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1
Moore, Bret A., Innfarn Yoo, Luke P. Tyrrell, Bedrich Benes, and Esteban Fernandez-Juricic. "FOVEA: a new program to standardize the measurement of foveal pit morphology." PeerJ 4 (April 11, 2016): e1785. http://dx.doi.org/10.7717/peerj.1785.
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The fovea is one of the most studied retinal specializations in vertebrates, which consists of an invagination of the retinal tissue with high packing of cone photoreceptors, leading to high visual resolution. Between species, foveae differ morphologically in the depth and width of the foveal pit and the steepness of the foveal walls, which could influence visual perception. However, there is no standardized methodology to measure the contour of the foveal pit across species. We present here FOVEA, a program for the quantification of foveal parameters (width, depth, slope of foveal pit) using images from histological cross-sections or optical coherence tomography (OCT). FOVEA is based on a new algorithm to detect the inner retina contour based on the color variation of the image. We evaluated FOVEA by comparing the fovea morphology of two Passerine birds based on histological cross-sections and its performance with data from previously published OCT images. FOVEA detected differences between species and its output was not significantly different from previous estimates using OCT software. FOVEA can be used for comparative studies to better understand the evolution of the fovea morphology in vertebrates as well as for diagnostic purposes in veterinary pathology. FOVEA is freely available for academic use and can be downloaded at:http://estebanfj.bio.purdue.edu/fovea.
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Bringmann, Andreas, Jan Darius Unterlauft, Renate Wiedemann, Thomas Barth, Matus Rehak, and Peter Wiedemann. "Two different populations of Müller cells stabilize the structure of the fovea: an optical coherence tomography study." International Ophthalmology 40, no. 11 (July 6, 2020): 2931–48. http://dx.doi.org/10.1007/s10792-020-01477-3.
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Abstract Purpose To document with spectral-domain optical coherence tomography the structural stabilization of the fovea and the sealing of outer macular defects by Müller cells. Methods A retrospective case series of 45 eyes of 34 patients is described. Results In cases of a cystic disruption of the foveola as in macular telangiectasia type 2 and vitreomacular traction, the Müller cell cone provides the structural stability of the fovea. In cases of a detachment or disruption of the Müller cell cone, e.g., in foveal pseudocysts, outer lamellar holes, and degenerative and tractional lamellar holes, Müller cells of the foveal walls may provide the structural stability of the fovea by the formation of a hyperreflective external limiting membrane (ELM) which bridges the holes in the central outer nuclear layer (ONL). Müller cells of the foveal walls and parafovea mediate the regeneration of the foveal architecture in cases of outer lamellar and full-thickness macular holes. The regeneration proceeds by a centripetal displacement of photoreceptor cell somata which closes the holes in the central ONL. The closure may be supported by the formation of a glial tissue band at the ELM which seals the hole. Conclusions The Müller cell cone provides the foveal stability in cases of a cystic disruption of the foveola. The structural stability of the outer foveal layers is mainly provided by the Müller cells of the foveal walls and parafovea; these cells also mediate the regeneration of the outer fovea in cases of a defect of the central ONL.
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THOMAS, LAURA P., and STEVEN L. BUCK. "Foveal and extra-foveal influences on rod hue biases." Visual Neuroscience 23, no. 3-4 (May 2006): 539–42. http://dx.doi.org/10.1017/s0952523806233509.
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Green, blue and short-wavelength-red rod hue biases are strongest and most reliable with large, dimly-mesopic, extra-foveal stimuli but tend to diminish when stimuli are confined to a small area of the central fovea. This study explores how the stimulation of foveal and extra-foveal areas interact in determining rod hue biases, and whether large stimuli are as effective for revealing rod hue biases when foveally centered as when eccentrically centered. We assessed rod influence by measuring wavelengths of unique green and unique yellow (with 1-s duration, 1 log scot td stimuli and a staircase procedure) under bleached and dark-adapted conditions. We measured unique hues with foveally centered 2°- and 7.4°-diameter disks, a 7.4° (outer) × 2° (inner) diameter annulus, and a 7°-eccentric, 7.4°-diameter disk. The rod green bias (shift of unique yellow locus) was typically <10 nm and remained fairly constant across spatial configurations, indicating no special foveal influence. The rod blue bias (shift of unique green) varied more among observers and spatial configurations, reaching up to 47 nm. However, stimuli covering the fovea typically produced no rod blue bias. Thus, the present results add differences in spatial dependence (i.e., foveal/extra-foveal interaction) between green and blue rod biases to previously demonstrated differences (e.g., differences in amount of light level dependence, in time course and in the spectral range influenced by each bias).
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Tang, Peter, Keiji Fujio, Robert Strauch, Melvin Rosenwasser, and Taiichi Matsumoto. "The Optimal Suture Placement and Bone Tunnels for TFCC Repair: A Cadaveric Study." Journal of Wrist Surgery 07, no. 05 (June 26, 2018): 375–81. http://dx.doi.org/10.1055/s-0038-1661361.
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Background Transosseous repair of foveal detachment of the triangular fibrocartilage complex (TFCC) is effective for distal radioulnar joint stabilization. However, studies of the optimal foveal and TFCC suture positions are scant. Purpose The purpose of this study was to clarify the optimal TFCC suture position and bone tunnels for transosseous foveal repair. Materials and Methods Seven cadavers were utilized. The TFCC was incised at the foveal insertion and sutured at six locations (TFCCs 1–6) using inelastic sutures. Six osseous tunnels were created in the fovea (foveae 1–6). Fovea 2 is located at the center of the circle formed by the ulnar head overlooking the distal end of the ulna (theoretical center of rotation); fovea 5 is located 2 mm ulnar to fovea 2. TFCC 5 is at the ulnar apex of the TFCC disc; TFCC 4 is 2 mm dorsal to TFCC 5. TFCC 1 to 6 sutures were then placed through each of the six osseous tunnels, resulting in 36 combinations, which were individually tested. The forearm was placed in five positions between supination and pronation, and the degree of suture displacement was measured. The position with the least displacement indicated the isometric point of the TFCC and fovea. Results The mean distance of suture displacement was 2.4 ± 1.6 mm. Fovea 2, combined with any TFCC location, (0.7 ± 0.6 mm) and fovea group 5, combined with TFCC 4 location (0.8 ± 0.8) or with TFCC 5 location (0.9 ± 0.6) had statistically shorter suture displacements than any other fovea groups. Conclusion For TFCC transosseous repair, osseous tunnel position was more important than TFCC suture location.
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LEE, HIE RIN, and KEELY M. BUMSTED O’BRIEN. "Morphological and behavioral limit of visual resolution in temperate (Hippocampus abdominalis) and tropical (Hippocampus taeniopterus) seahorses." Visual Neuroscience 28, no. 4 (June 23, 2011): 351–60. http://dx.doi.org/10.1017/s0952523811000149.
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AbstractSeahorses are visually guided feeders that prey upon small fast-moving crustaceans. Seahorse habitats range from clear tropical to turbid temperate waters. How are seahorse retinae specialized to mediate vision in these diverse environments? Most species of seahorse have a specialization in their retina associated with acute vision, the fovea. The purpose of this study was to characterize the fovea of temperate Hippocampus abdominalis and tropical H. taeniopterus seahorses and to investigate their theoretical and behavioral limits of visual resolution. Their foveae were identified and photoreceptor (PR) and ganglion cell (GC) densities determined throughout the retina and topographically mapped. The theoretical limit of visual resolution was calculated using formulas taking into account lens radius and either cone PR or GC densities. Visual resolution was determined behaviorally using reactive distance. Both species possess a rod-free convexiclivate fovea. PR and GC densities were highest along the foveal slope, with a density decrease within the foveal center. Outside the fovea, there was a gradual density decrease towards the periphery. The theoretically calculated visual resolution on the foveal slope was poorer for H. abdominalis (5.25 min of arc) compared with H. taeniopterus (4.63 min of arc) based on PR density. Using GC density, H. abdominalis (9.81 min of arc) had a lower resolution compared with H. taeniopterus (9.04 min of arc). Behaviorally, H. abdominalis had a resolution limit of 1090.64 min of arc, while H. taeniopterus was much smaller, 692.86 min of arc. Although both species possess a fovea and the distribution of PR and GC is similar, H. taeniopterus has higher PR and GC densities on the foveal slope and better theoretical and behaviorally measured visual resolution compared to H. abdominalis. These data indicate that seahorses have a well-developed acute visual system, and tropical seahorses have higher visual resolution compared to temperate seahorses.
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Bringmann, Andreas, Jan Darius Unterlauft, Thomas Barth, Renate Wiedemann, Leon Kohen, Matus Rehak, and Peter Wiedemann. "Foveal regeneration after resolution of cystoid macular edema without and with internal limiting membrane detachment: presumed role of glial cells for foveal structure stabilization." International Journal of Ophthalmology 14, no. 6 (June 18, 2021): 818–33. http://dx.doi.org/10.18240/ijo.2021.06.06.
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AIM: To document with spectral-domain optical coherence tomography the morphological regeneration of the fovea after resolution of cystoid macular edema (CME) without and with internal limiting membrane (ILM) detachment and to discuss the presumed role of the glial scaffold for foveal structure stabilization. METHODS: A retrospective case series of 38 eyes of 35 patients is described. Of these, 17 eyes of 16 patients displayed foveal regeneration after resolution of CME, and 6 eyes of 6 patients displayed CME with ILM detachment. Eleven eyes of 9 patients displayed other kinds of foveal and retinal disorders associated with ILM detachment. RESULTS: The pattern of edematous cyst distribution, with or without a large cyst in the foveola and preferred location of cysts in the inner nuclear layer or Henle fiber layer (HFL), may vary between different eyes with CME or in one eye during different CME episodes. Large cysts in the foveola may be associated with a tractional elevation of the inner foveal layers and the formation of a foveoschisis in the HFL. Edematous cysts are usually not formed in the ganglion cell layer. Eyes with CME and ILM detachment display a schisis between the detached ILM and nerve fiber layer (NFL) which is traversed by Müller cell trunks. ILM detachment was also found in single eyes with myopic traction maculopathy, macular pucker, full-thickness macular holes, outer lamellar holes, and glaucomatous parapapillary retinoschisis, and in 3 eyes with Müller cell sheen dystrophy (MCSD). As observed in eyes with MCSD, cellophane maculopathy, and macular pucker, respectively, fundus light reflections can be caused by different highly reflective membranes or layers: the thickened and tightened ILM which may or may not be detached from the NFL, the NFL, or idiopathic epiretinal membranes. In eyes with short single or multiple CME episodes, the central fovea regenerated either completely, which included the disappearance of irregularities of the photoreceptor layer lines and the reformation of a fovea externa, or with remaining irregularities of the photoreceptor layer lines. CONCLUSION: The examples of a complete regeneration of the foveal morphology after transient CME show that the fovea may withstand even large tractional deformations and has a conspicuous capacity of structural regeneration as long as no cell degeneration occurs. It is suggested that the regenerative capacity depends on the integrity of the threedimensional glial scaffold for foveal structure stabilization composed of Müller cell and astrocyte processes. The glial scaffold may also maintain the retinal structure after loss of most retinal neurons as in late-stage MCSD.
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CORNISH, ELISA E., MICHELE C. MADIGAN, RICCARDO NATOLI, ANGELA HALES, ANITA E. HENDRICKSON, and JAN M. PROVIS. "Gradients of cone differentiation and FGF expression during development of the foveal depression in macaque retina." Visual Neuroscience 22, no. 4 (July 2005): 447–59. http://dx.doi.org/10.1017/s0952523805224069.
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Cones in the foveola of adult primate retina are narrower and more elongated than cones on the foveal rim, which in turn, are narrower and more elongated than those located more eccentric. This gradient of cone morphology is directly correlated with cone density and acuity. Here we investigate the hypothesis that fibroblast growth factor (FGF) signaling mediates the morphological differentiation of foveal cones—in particular, the mechanism regulating the elongation of foveal cones. We used immunoreactivity to FGF receptor (R) 4, and quantitative analysis to study cone elongation on the horizontal meridian of macaque retinae, aged between foetal day (Fd) 95 and 2.5 years postnatal (P 2.5y). We also used in situ hybridization and immunohistochemistry to investigate the expression patterns of FGF2 and FGFR1–4 at the developing fovea, and three other sample locations on the horizontal meridian. Labeled RNA was detected using the fluorescent marker “Fast Red” (Roche) and levels of expression in cone inner segments and in the ganglion cell layer (GCL) were compared using confocal microscopy, optical densitometry, and tested for statistical significance. Our results show that morphological differentiation of cones begins near the optic disc around Fd 95, progressing toward the developing fovea up until birth, approximately. Levels of FGF2 and FGFR4 mRNAs expression are low in foveal cones, compared with cones closer to the optic disc, during this period. There is no similar gradient of FGF2 mRNA expression in the ganglion cell layer of the same sections. Maturation of foveal cones is delayed until the postnatal period. The results suggest that a wave of cone differentiation spreads from the disc region toward the developing fovea during the second half of gestation in the macaque. A gradient of expression of FGFR4 and FGF2 associated with the wave of differentiation suggests that FGF signalling mediates cone narrowing and elongation.
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Angermann, Reinhard, Nikolaos E. Bechrakis, Teresa Rauchegger, Marina Casazza, Yvonne Nowosielski, and Claus Zehetner. "Effect of Timing on Visual Outcomes in Fovea-Involving Retinal Detachments Verified by SD-OCT." Journal of Ophthalmology 2020 (February 22, 2020): 1–5. http://dx.doi.org/10.1155/2020/2307935.
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Purpose. To investigate the impact of surgical delay after the objectivation of the foveal status by spectral-domain optical coherence tomography (SD-OCT) on visual outcomes in patients with rhegmatogenous retinal detachment (RRD) with foveal involvement. Methods. A retrospective dataset analysis of 508 eyes of 504 consecutive patients with primary RRD was performed. The primary outcome measure was the best-corrected visual acuity as a function of time between the assessment of the foveal status with SD-OCT upon initial examination at the department and RRD repair. Results. In total, 188 eyes (37.0%) had a complete foveal detachment and 31 (6.1%) eyes had a bisected fovea by the retinal detachment. A hundred eyes with total foveal detachment received surgery within 24 h and 65 eyes between 24 h and 72 h. Visual outcomes for eyes with detached fovea were significantly better when treated within 24 h (0.47 ± 0.39) compared with those treated between 24 h and 72 h (0.84 ± 0.66; p=0.01) after objectivation of the foveal status with SD-OCT. Pars plana vitrectomy was performed in 174 (92.6%) eyes and scleral buckling surgery in 14 (7.4%) eyes with complete foveal involvement of RRD. Conclusions. Our findings suggest improved visual outcomes for patients receiving surgery within 24 h after a definitive diagnosis of fovea-involving RRD compared to surgical interventions that were further delayed.
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Shelchkova, Natalya, and Martina Poletti. "Modulations of foveal vision associated with microsaccade preparation." Proceedings of the National Academy of Sciences 117, no. 20 (May 1, 2020): 11178–83. http://dx.doi.org/10.1073/pnas.1919832117.
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It is known that attention shifts prior to a saccade to start processing the saccade target before it lands in the foveola, the high-resolution region of the retina. Yet, once the target is foveated, microsaccades, tiny saccades maintaining the fixated object within the fovea, continue to occur. What is the link between these eye movements and attention? There is growing evidence that these eye movements are associated with covert shifts of attention in the visual periphery, when the attended stimuli are presented far from the center of gaze. Yet, microsaccades are primarily used to explore complex foveal stimuli and to optimize fine spatial vision in the foveola, suggesting that the influences of microsaccades on attention may predominantly impact vision at this scale. To address this question we tracked gaze position with high precision and briefly presented high-acuity stimuli at predefined foveal locations right before microsaccade execution. Our results show that visual discrimination changes prior to microsaccade onset. An enhancement occurs at the microsaccade target location. This modulation is highly selective and it is coupled with a drastic impairment at the opposite foveal location, just a few arcminutes away. This effect is strongest when stimuli are presented closer to the eye movement onset time. These findings reveal that the link between attention and microsaccades is deeper than previously thought, exerting its strongest effects within the foveola. As a result, during fixation, foveal vision is constantly being reshaped both in space and in time with the occurrence of microsaccades.
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SPRINGER, ALAN D., DAVID TROILO, DANIEL POSSIN, and ANITA E. HENDRICKSON. "Foveal cone density shows a rapid postnatal maturation in the marmoset monkey." Visual Neuroscience 28, no. 6 (November 2011): 473–84. http://dx.doi.org/10.1017/s0952523811000332.
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AbstractThe spatial and temporal pattern of cone packing during marmoset foveal development was explored to understand the variables involved in creating a high acuity area. Retinal ages were between fetal day (Fd) 125 and 6 years. Cone density was determined in wholemounts using a new hexagonal quantification method. Wholemounts were labeled immunocytochemically with rod markers to identify reliably the foveal center. Cones were counted in small windows and density was expressed as cones × 103/mm2 (K). Two weeks before birth (Fd 125–130), cone density had a flat distribution of 20–30 K across the central retina encompassing the fovea. Density began to rise at postnatal day 1 (Pd 1) around, but not in, the foveal center and reached a parafoveal peak of 45–55 K by Pd 10. Between Pd 10 and 33, there was an inversion such that cone density at the foveal center rose rapidly, reaching 283 K by 3 months and 600 K by 5.4 months. Peak foveal density then diminished to 440 K at 6 months and older. Counts done in sections showed the same pattern of low foveal density up to Pd 1, a rapid rise from Pd 30 to 90, followed by a small decrease into adulthood. Increasing foveal cone density was accompanied by 1) a reduction in the amount of Müller cell cytoplasm surrounding each cone, 2) increased stacking of foveal cone nuclei into a mound 6–10 deep, and 3) a progressive narrowing of the rod-free zone surrounding the fovea. Retaining foveal cones in a monolayer precludes final foveal cone densities above 60 K. However, high foveal adult cone density (300 K) can be achieved by having cone nuclei stack into columns and without reducing their nuclear diameter. Marmosets reach adult peak cone density by 3–6 months postnatal, while macaques and humans take much longer. Early weaning and an arboreal environment may require rapid postnatal maturation of the marmoset fovea.
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Bringmann, Andreas, Jan Darius Unterlauft, Renate Wiedemann, Thomas Barth, Matus Rehak, and Peter Wiedemann. "Degenerative lamellar macular holes: tractional development and morphological alterations." International Ophthalmology 41, no. 4 (January 12, 2021): 1203–21. http://dx.doi.org/10.1007/s10792-020-01674-0.
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Abstract Purpose The development of degenerative lamellar macular holes (DLH) is largely unclear. This study was aimed at documenting with spectral-domain optical coherence tomography the tractional development and morphological alterations of DLH. Methods A retrospective case series of 44 eyes of 44 patients is described. Results The development of DLH is preceded for months or years by tractional deformations of the fovea due to the action of contractile epiretinal membranes (ERM) and/or the partially detached posterior hyaloid, or by cystoid macular edema (CME). DLH may develop after a tractional stretching and thickening of the foveal center, from a foveal pseudocyst, after a detachment of the foveola from the retinal pigment epithelium, a disruption of the foveal structure due to CME, and after surgical treatment of tractional lamellar or full-thickness macular holes (FTMH). The foveal configuration of a DLH can be spontaneously reestablished after short transient episodes of CME and a small FTMH. A DLH can evolve to a FTMH by traction of an ERM. Surgical treatment of a DLH may result in an irregular regeneration of the foveal center without photoreceptors. Conclusions Tractional forces play an important role in the development of DLH and in the further evolution to FTMH. It is suggested that a DLH is the result of a retinal wound repair process after a tractional disruption of the Müller cell cone and a degeneration of Henle fibers, to prevent a further increase in the degenerative cavitations.
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Mota, Ágata, Sofia Fonseca, Ângela Carneiro, Augusto Magalhães, Elisete Brandão, and Fernando Falcão-Reis. "Isolated Foveal Hypoplasia: Tomographic, Angiographic and Autofluorescence Patterns." Case Reports in Ophthalmological Medicine 2012 (2012): 1–3. http://dx.doi.org/10.1155/2012/864958.
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Purpose. To report clinical aspects, tomographic, angiographic, and autofluorescence patterns of two cases of isolated foveal hypoplasia.Methods. Foveal hypoplasia was found in a 23-year-old male patient and in a 64-year-old woman with impaired visual acuity of unknown etiology that remained unchanged for years.Results. In the first case, spectral-domain optical coherence tomography (SD-OCT) showed reduced foveal pit and continuity of inner retinal layers in the fovea. Photoreceptor layer had a normal thickness centrally. The foveal avascular zone (FAZ) was absent in the flourescein angiogram (FA). Fundus autofluorescence showed reduced foveal attenuation of autofluorescence. In the second patient, there was the same pattern in SD-OCT, with normal aspect in FA and only a slightly reduced foveal attenuation of autofluorescence.Conclusion. OCT, as a noninvasive and quick method, is helpful in the diagnosis of foveal hypoplasia. FA and fundus autofluorescence were less sensitive.
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Rogowska, Anna, Łukasz Obrycki, Zbigniew Kułaga, Claudia Kowalewska, and Mieczysław Litwin. "Remodeling of Retinal Microcirculation Is Associated With Subclinical Arterial Injury in Hypertensive Children." Hypertension 77, no. 4 (April 2021): 1203–11. http://dx.doi.org/10.1161/hypertensionaha.120.16734.
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The aim of the study was to assess the relationship between hypertensive target organ damage and vessel density (VD), foveal thickness, thickness of retinal nerve fiber layer, ganglion cell complex, and foveal avascular zone (FAZ) using optical coherence tomography angiography in a nonselected group of hypertensive children. One hundred fifty-seven children (56 girls) in mean age 14.9±2.9 years, in whom arterial hypertension was ultimately diagnosed were included in the study. FAZ, whole, fovea, parafovea superficial VD, whole, fovea, parafovea deep VD, foveal thickness, retinal nerve fiber layer, and ganglion cell complex were taken into analysis. Both absolute and standardized values of carotid intima-media thickness correlated with the larger FAZ area ( P =0.035, r =0.17; P =0.01, r =0.2, respectively). Subjects with increased carotid intima-media thickness had significantly larger FAZ ( P =0.024), reduced fovea superficial VD ( P =0.039), and foveal thickness ( P =0.007). Left ventricular hypertrophy and increased carotid-femoral pulse wave velocity were not associated with optical coherence tomography angiography parameters. Multiple linear regression revealed that the only determinant of FAZ and foveal thickness was higher carotid intima-media thickness–SD score, and for fovea superficial VD, the only determinant was central systolic blood pressure. In conclusion, hypertensive children present with signs of remodeling of microcirculation and decreased neural layer of retina associated with hypertensive macrocirculation remodeling expressed as increased carotid intima-media thickness and elevated central systolic blood pressure.
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SPRINGER, ALAN D. "New role for the primate fovea: A retinal excavation determines photoreceptor deployment and shape." Visual Neuroscience 16, no. 4 (July 1999): 629–36. http://dx.doi.org/10.1017/s0952523899164034.
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In humans, an increasing density of foveal cone photoreceptors occurs slowly over several years after birth, and accounts for a region that subserves high visual acuity. Concurrently, inner retinal cells move centrifugally away from the foveal center. Such developmental rearrangements reflect complex cellular remodeling after the retinal neuronal cells have differentiated and have formed synapses. Explaining foveal morphogenesis is difficult, because differentiated neuronal cells seem incapable of moving actively. Presented here is a biomechanical explanation of how the above events occur. This hypothesis assumes that the cellular movements throughout the retinal layers occur passively as the eye grows and the retina is stretched. Retinal stretch was simulated using virtual engineering models that were analyzed with finite element analysis. A pit combined with retinal stretch causes the retinal layers to deform in a way that accounts for both the centrifugal and centripetal movement of various retinal cell types. Axially directed, tensile forces associated with stretching the retinal tissue surrounding the pit also accounts for the elongated morphology of foveal cone photoreceptors. These simulations suggest that a pit is required for both the centripetal displacement of cone cells toward the center of the fovea, and for the elongated foveal cone morphology. Since the primate fovea may have minimal impact on acuity, its primary role may be to initiate foveal morphogenesis in slowly developing eyes.
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Leisser, Christoph, and Oliver Findl. "Foveal-Sparing ILM Peeling in a Case with Vitreomacular Traction and Foveal Detachment." Case Reports in Ophthalmology 12, no. 1 (April 12, 2021): 182–85. http://dx.doi.org/10.1159/000510957.
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A pseudophakic female patient, 80 years of age, presented with a vitreomacular traction and foveal detachment at her right eye. To avoid development of a full-thickness macular hole during surgery, foveal-sparing ILM peeling was performed. After surgery, distance-corrected visual acuity increased from 0.3 to 0.6 (Snellen) 3 months after surgery and fovea was re-attached again with restoration of the retinal layers.
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Soliman, Sameh E., Cynthia VandenHoven, Leslie D. Mackeen, and Brenda L. Gallie. "Vision and visual potential for perifoveal retinoblastoma after optical coherence tomographic-guided sequential laser photocoagulation." British Journal of Ophthalmology 103, no. 6 (July 5, 2018): 753–60. http://dx.doi.org/10.1136/bjophthalmol-2018-312125.
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Background/aimsTo assess tumour control, vision and anatomical visual potential in eyes with perifoveal retinoblastoma treated by sequential photocoagulation from the antifoveal tumour edge inwards, avoiding treatment near the fovea. Patients were monitored for tumour control, foveal and perifoveal anatomy at each treatment session by optical coherence tomography (OCT) and treated for amblyopia when the other eye had better vision.MethodsEyes with perifoveal retinoblastoma treated between 1 January 2011 and 31 May 2017 with laser therapy after chemotherapy for juxtafoveal (fovea clear of tumour but <3000 µm from tumour edge) or foveolar retinoblastoma (tumour underlying fovea) were retrospectively reviewed for tumour control without recurrence, anatomical success (foveal pit preservation and/or restoration with ≥500 µm perifoveal retina free of tumour and scar) and functional success (acceptable (>0.1 decimal) or good (>0.3 decimal) visual acuity (VA)).ResultsTwenty-two eyes (14 juxtafoveal, 8 foveolar tumours) of 20 patients (19 bilateral, 1 familial and 11 females) were included. No juxtafoveal tumour had tumour recurrence, and 13/14 patients showed foveal pit preservation with ≥500 µm of perifoveal retina tumour free. Foveolar tumours had significant worse anatomical outcomes: failure to restore foveal pit or perifoveal retina (8/8, p=0.001) and tumour recurrences (5/8, p=0.001). Functional success with acceptable VA was achieved in 12/14 juxtafoveal and 5/8 foveal tumours eyes (p=0.01). Amblyopia therapy data were insufficient to evaluate impact on VA.ConclusionsAnatomical visual potential and functional vision were better in juxtafoveal than foveolar retinoblastoma treated with foveal-sparing laser photocoagulation guided by OCT. The role of amblyopia therapy requires a prospective study.
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Keles, Ali, Cagri Ilhan, Mehmet Yasin Teke, and Kemal Tekin. "Septo-optic dysplasia with fovea plana: A case report." European Journal of Ophthalmology 30, no. 5 (June 12, 2020): NP36—NP40. http://dx.doi.org/10.1177/1120672120934961.
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Septo-optic dysplasia (SOD) is characterized by optic nerve hypoplasia, pituitary gland hypoplasia, and midline abnormalities of the brain. The phenotype of SOD is highly heterogeneous, and the existence of at least two features is considered sufficient for diagnosis. Fovea plana is the absence of a foveal pit in the central fovea, and despite being a developmental abnormality of the fovea, good visual acuity may be retained in some individuals. In this case, a 12-year-old female presented to the ophthalmology clinic with the complaint of blurred vision in her right eye. In dilated fundus examination, optic disc hypoplasia and no foveal light reflex were seen. Magnetic resonance imaging and optical coherence tomography revealed optic nerve, brain midline, and foveal abnormalities. The patient was diagnosed as having SOD with optic nerve hypoplasia and septum pellucidum agenesis, and fovea plana. Both SOD and fovea plana are rare conditions, and there are several reports in the literature that separately describe their clinical features. The most important aspect of this case report is to reveal the unusual co-existence of SOD and fovea plana in a young patient.
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Bagheri, Saghar, Ines Lains, Rebecca F. Silverman, Ivana Kim, Dean Eliott, Rufino Silva, John Miller, et al. "Percentage of Foveal vs Total Macular Geographic Atrophy as a Predictor of Visual Acuity in Age-Related Macular Degeneration." Journal of VitreoRetinal Diseases 3, no. 5 (August 22, 2019): 278–82. http://dx.doi.org/10.1177/2474126419859454.
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Purpose: This article investigates the relationship between visual acuity (VA), total area of geographic atrophy (GA), and percentage of foveal GA. Methods: A multicenter, retrospective, cross-sectional study was conducted of patients with GA due to age-related macular degeneration. Demographics, VA, fundus autofluorescence (FAF), and spectral-domain optical coherence tomography (SD-OCT) images were collected. Using FAF images aided by SD-OCT, fovea-sparing status, GA pattern, total GA size, and percentage of GA covering the foveal area—within a 1.5-mm-diameter circle centered on the fovea centralis—were assessed. Univariable and multiple linear regression analyses were performed. Results: Fifty-four eyes (mean age, 78.7 ±7.7 years [SD], 60.0% female) were studied. Mean VA was 0.8 ± 0.6 logarithm of the minimum angle of resolution (Snellen equivalent 20/126 ± 20/80), mean total GA 8.8 ± 6.7 mm2, and mean percentage of foveal GA was 71.5 ± 30.9%. Of all assessed eyes, 48.2% (n = 26) presented with multifocal GA, and 18.5% (n = 10) had foveal sparing. Multiple regression analysis revealed that, controlling for age and GA pattern, the percentage of foveal GA presented a statistically significant association with VA (ß = 0.41, P = .004). No significant associations were observed with mean total GA size, while controlling for the same variables (ß = 0.010, P = .440). Conclusions: Percentage of foveal GA was significantly associated with VA impairment, although the same was not verified for total GA area. These findings suggest that percentage of foveal GA may represent a more useful tool for assessing the impact of GA on VA. Further validation is needed in larger cohorts.
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Fan, Xiaoxu, Lan Wang, Hanyu Shao, Daniel Kersten, and Sheng He. "Temporally flexible feedback signal to foveal cortex for peripheral object recognition." Proceedings of the National Academy of Sciences 113, no. 41 (September 26, 2016): 11627–32. http://dx.doi.org/10.1073/pnas.1606137113.
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Recent studies have shown that information from peripherally presented images is present in the human foveal retinotopic cortex, presumably because of feedback signals. We investigated this potential feedback signal by presenting noise in fovea at different object–noise stimulus onset asynchronies (SOAs), whereas subjects performed a discrimination task on peripheral objects. Results revealed a selective impairment of performance when foveal noise was presented at 250-ms SOA, but only for tasks that required comparing objects’ spatial details, suggesting a task- and stimulus-dependent foveal processing mechanism. Critically, the temporal window of foveal processing was shifted when mental rotation was required for the peripheral objects, indicating that the foveal retinotopic processing is not automatically engaged at a fixed time following peripheral stimulation; rather, it occurs at a stage when detailed information is required. Moreover, fMRI measurements using multivoxel pattern analysis showed that both image and object category-relevant information of peripheral objects was represented in the foveal cortex. Taken together, our results support the hypothesis of a temporally flexible feedback signal to the foveal retinotopic cortex when discriminating objects in the visual periphery.
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Scherberich, Jan, Roxana Taszus, Alexander Stoessel, and Manuela Nowotny. "Comparative micromechanics of bushcricket ears with and without a specialized auditory fovea region in the crista acustica." Proceedings of the Royal Society B: Biological Sciences 287, no. 1929 (June 24, 2020): 20200909. http://dx.doi.org/10.1098/rspb.2020.0909.
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In some insects and vertebrate species, the specific enlargement of sensory cell epithelium facilitates the perception of particular behaviourally relevant signals. The insect auditory fovea in the ear of the bushcricket Ancylecha fenestrata (Tettigoniidae: Phaneropterinae) is an example of such an expansion of sensory epithelium. Bushcricket ears developed in convergent evolution anatomical and functional similarities to mammal ears, such as travelling waves and auditory foveae, to process information by sound. As in vertebrate ears, sound induces a motion of this insect hearing organ (crista acustica), which can be characterized by its amplitude and phase response. However, detailed micromechanics in this bushcricket ear with an auditory fovea are yet unknown. Here, we fill this gap in knowledge for bushcricket, by analysing and comparing the ear micromechanics in Ancylecha fenestrata and a bushcricket species without auditory fovea ( Mecopoda elongata , Tettigoniidae: Mecopodinae) using laser-Doppler vibrometry. We found that the increased size of the crista acustica, expanded by a foveal region in A. fenestrata , leads to higher mechanical amplitudes and longer phase delays in A. fenestrata male ears. Furthermore, area under curve analyses of the organ oscillations reveal that more sensory units are activated by the same stimuli in the males of the auditory fovea-possessing species A. fenestrata . The measured increase of phase delay in the region of the auditory fovea supports the conclusion that tilting of the transduction site is important for the effective opening of the involved transduction channels. Our detailed analysis of sound-induced micromechanics in this bushcricket ear demonstrates that an increase of sensory epithelium with foveal characteristics can enhance signal detection and may also improve the neuronal encoding.
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Diaz Araya, Claudia, and Jan M. Provis. "Evidence of photoreceptor migration during early foveal development: A quantitative analysis of human fetal retinae." Visual Neuroscience 8, no. 6 (June 1992): 505–14. http://dx.doi.org/10.1017/s0952523800005605.
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AbstractWe have analyzed aspects of photoreceptor topography in wholemounts of human fetal retinae in the age range 13–24 weeks of gestation. Fetal retinae were stained with cresyl violet and the sizes and packing densities of rods and cones analyzed in the conventional manner.Cones and rods were present within a differentiating region, free of mitotic figures and approximately centered on the putative fovea, represented by the foveal cone mosaic. At 13 weeks of gestation the foveal cone mosaic was clearly differentiated, cone nuclei reaching a packing density of 14,200 per mm; a small number of rods were present in the immediately adjacent region. The packing densities of both rods and cones in these regions gradually increased and the area of the foveal cone mosaic gradually decreased throughout the age range sampled, although individual variations were evident. By 24 weeks of gestation, cone density was approximately 38,000 per mm in the foveal cone mosaic. The maximum rod density observed was 59,200 per mm in the region surrounding the foveal cone mosaic in a specimen of 20–21 weeks of gestation. In all specimens, maximum cone density occurred within the foveal cone mosaic and gradually declined towards the periphery of the differentiating region; a pronounced inverse relationship between cone soma diameter and packing density was also observed. The evidence strongly suggests that both rods and cones migrate centripetally, that is towards the center of the developing fovea, from early in development, possibly from the time that they first differentiate. The implications of these findings for fovealdevelopment are discussed.
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Song, Hongxin, Ethan A. Rossi, and David R. Williams. "Reduced foveal cone density in early idiopathic macular telangiectasia." BMJ Open Ophthalmology 6, no. 1 (January 2021): e000603. http://dx.doi.org/10.1136/bmjophth-2020-000603.
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ObjectiveIdiopathic macular telangiectasia (MacTel) is considered primarily a vascular disease affecting juxtafoveal retinal capillaries. However, recent evidence suggests that neuronal changes may occur early in disease development. We used high-resolution adaptive optics retinal imaging to elucidate the foveal cone photoreceptor changes at a cellular level in patients with MacTel.Methods and analysisWe used adaptive optics scanning light ophthalmoscopy (AOSLO) to evaluate the foveal cone photoreceptors in the less-affected eye of patients with asymmetric MacTel. AOSLO images of cone photoreceptors were obtained in a 4°×4° area centred on the foveola. Individual cone positions were identified within a 2°×2° area centred on the fovea, using semiautomatic cone marking software with manual correction, permitting calculation of a map of cone density.ResultsIn all participants, one eye was affected with MacTel, the fellow eye was clinically normal or near normal, with visual acuity of 20/25 or better and subtle angiographic leakage. The foveal cone mosaics were continuous with tight packing and cones exhibited normal reflectivity. However, cone density was significantly lower for all participants (mean=80 733 cones/mm2) within 0.5° than the cone density previously reported for normal eyes.ConclusionsFoveal cone density is lower than normal in the clinically less-affected eyes of patients with asymmetric MacTel. This suggests that cone photoreceptor loss may precede classic obvious vascular changes in idiopathic MacTel.
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Song, Hongxin, Ethan A. Rossi, and David R. Williams. "Reduced foveal cone density in early idiopathic macular telangiectasia." BMJ Open Ophthalmology 6, no. 1 (January 2021): e000603. http://dx.doi.org/10.1136/bmjophth-2020-000603.
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ObjectiveIdiopathic macular telangiectasia (MacTel) is considered primarily a vascular disease affecting juxtafoveal retinal capillaries. However, recent evidence suggests that neuronal changes may occur early in disease development. We used high-resolution adaptive optics retinal imaging to elucidate the foveal cone photoreceptor changes at a cellular level in patients with MacTel.Methods and analysisWe used adaptive optics scanning light ophthalmoscopy (AOSLO) to evaluate the foveal cone photoreceptors in the less-affected eye of patients with asymmetric MacTel. AOSLO images of cone photoreceptors were obtained in a 4°×4° area centred on the foveola. Individual cone positions were identified within a 2°×2° area centred on the fovea, using semiautomatic cone marking software with manual correction, permitting calculation of a map of cone density.ResultsIn all participants, one eye was affected with MacTel, the fellow eye was clinically normal or near normal, with visual acuity of 20/25 or better and subtle angiographic leakage. The foveal cone mosaics were continuous with tight packing and cones exhibited normal reflectivity. However, cone density was significantly lower for all participants (mean=80 733 cones/mm2) within 0.5° than the cone density previously reported for normal eyes.ConclusionsFoveal cone density is lower than normal in the clinically less-affected eyes of patients with asymmetric MacTel. This suggests that cone photoreceptor loss may precede classic obvious vascular changes in idiopathic MacTel.
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Wade, Alex R., Alyssa A. Brewer, Jochem W. Rieger, and Brian A. Wandell. "Functional measurements of human ventral occipital cortex: retinotopy and colour." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 357, no. 1424 (August 29, 2002): 963–73. http://dx.doi.org/10.1098/rstb.2002.1108.
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Human colour vision originates in the cone photoreceptors, whose spatial density peaks in the fovea and declines rapidly into the periphery. For this reason, one expects to find a large representation of the cone–rich fovea in those cortical locations that support colour perception. Human occipital cortex contains several distinct foveal representations including at least two that extend onto the ventral surface: a region thought to be critical for colour vision. To learn more about these ventral signals, we used functional magnetic resonance imaging to identify visual field maps and colour responsivity on the ventral surface. We found a visual map of the complete contralateral hemifield in a 4 cm 2 region adjacent to ventral V3; the foveal representation of this map is confluent with that of areas V1/2/3. Additionally, a distinct foveal representation is present on the ventral surface situated 3–5 cm anterior from the confluent V1/2/3 foveal representations. This organization is not consistent with the definition of area V8, which assumes the presence of a quarter field representation adjacent to V3v. Comparisons of responses to luminance–matched coloured and achromatic patterns show increased activity to the coloured stimuli beginning in area V1 and extending through the new hemifield representation and further anterior in the ventral occipital lobe.
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Shrier, Eric M., Christopher R. Adam, Brian Spund, Sofya Glazman, and Ivan Bodis-Wollner. "Interocular Asymmetry of Foveal Thickness in Parkinson Disease." Journal of Ophthalmology 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/728457.
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Purpose. To quantify interocular asymmetry (IA) of foveal thickness in Parkinson disease (PD) versus that of controls.Design. Prospective case-control series.Methods.In vivoassessment of foveal thickness of 46 eyes of 23 PD patients and 36 eyes of 18 control subjects was studied using spectral domain optical coherence tomography (SD-OCT). Inner versus outer layer retinal segmentation and macular volumes were quantified using the manufacturer's software, while foveal thickness was measured using the raw data from each eye in a grid covering a 6 by 6 mm area centered on the foveola in 0.25 mm steps. Thickness data were entered into MATLAB software.Results. Macular volumes differed significantly at the largest (Zone 3) diameter centered on the foveola (ETDRS protocol). By segmenting inner from outer layers, we found that the IA in PD is mostly due to changes on the slope of the foveal pit at the radial distances of 0.5 and 0.75 mm (1.5 mm and 1 mm diameter).Conclusions. About half of the PD patients had IA of the slope of the foveal pit. IA is a potentially useful marker of PD and is expected to be comparable across different SD-OCT equipment. Data of larger groups may be developed in future multicenter studies.
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Hernandez-Moreno, Laura, Natacha Moreno Perdomo, Tomas S. Aleman, Karthikeyan Baskaran, and Antonio Filipe Macedo. "Absent Foveal Pit, Also Known as Fovea Plana, in a Child without Associated Ocular or Systemic Findings." Case Reports in Ophthalmological Medicine 2018 (July 26, 2018): 1–5. http://dx.doi.org/10.1155/2018/2146826.
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The purpose of this report is to describe a case of bilateral foveal hypoplasia in the absence of other ophthalmological or systemic manifestations. We characterize the case of a 9-year-old Caucasian male who underwent full ophthalmologic examination, including functional measures of vision and structural measurements of the eye. Best corrected visual acuity was 0.50 logMAR in the right eye and 0.40 logMAR in the left eye. Ophthalmoscopy revealed a lack of foveal reflex that was further investigated. Optical coherence tomography (OCT) confirmed the absence of foveal depression (pit). OCT images demonstrated the abnormal structure of retina in a region in which we expected a fovea; these findings were decisive to determine the cause of reduced acuity in the child.
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Collin, Shaun P., Darren J. Lloyd, and Hans–Joachim Wagner. "Foveate vision in deep–sea teleosts: a comparison of primary visual and olfactory inputs." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 355, no. 1401 (September 29, 2000): 1315–20. http://dx.doi.org/10.1098/rstb.2000.0691.
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The relative importance of vision in a foveate group of alepocephalid teleosts is examined in the context of a deep–sea habitat beyond the penetration limits of sunlight. The large eyes of Conocara spp. possess deep convexiclivate foveae lined with Müller cells comprising radial shafts of intermediate filaments and horizontal processes. Photoreceptor cell (171.8 × 10 3 rods mm −2 ) and retinal ganglion cell (11.9 × 10 3 cells mm −2 ) densities peak within the foveal clivus and the perifoveal slopes, respectively, with a centro–peripheral gradient between 3:1 (photoreceptors) and over 20:1 (ganglion cells). The marked increase in retinal sampling localized in temporal retina, coupled with a high summation ratio (13:1), suggest that foveal vision optimizes both spatial resolving power and sensitivity in the binocular frontal visual field. The elongated optic nerve head is comprised of over 500 optic papillae, which join at the embryonic fissure to form a thin nervous sheet behind the eye. The optic nerve is divided into two axonal bundles; one receiving input from the fovea (only unmyelinated axons) and the other from non–specialized retinal regions (25% of axons are myelinated), both of which appear to be separated as they reach the visual centres of the central nervous system. Comparison of the number of primary (first–order) axonal pathways for the visual (a total of 63.4 × 10 6 rod photoreceptors) and olfactory (a total of 15.24 × 10 5 olfactory nerve axons) inputs shows a marked visual bias (ratio of 41:1). Coupled with the relative size of the optic tecta (44.0 mm 3 ) and olfactory bulbs (0.9 mm 3 ), vision appears to play a major role in the survival of these deep–sea teleosts and emphasizes that ecological and behavioural strategies account for significant variation in sensory brain structure.
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Hafed, Ziad M., Chih-Yang Chen, Xiaoguang Tian, Matthias P. Baumann, and Tong Zhang. "Active vision at the foveal scale in the primate superior colliculus." Journal of Neurophysiology 125, no. 4 (April 1, 2021): 1121–38. http://dx.doi.org/10.1152/jn.00724.2020.
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The primate superior colliculus (SC) has recently been shown to possess both a large foveal representation as well as a varied visual processing repertoire. This structure is also known to contribute to eye movement generation. Here, we describe our current understanding of how SC visual and movement-related signals interact within the realm of small eye movements associated with the foveal scale of visuomotor behavior. Within the SC’s foveal representation, there is a full spectrum of visual, visual-motor, and motor-related discharge for fixational eye movements. Moreover, a substantial number of neurons only emit movement-related discharge when microsaccades are visually guided, but not when similar movements are generated toward a blank. This represents a particularly striking example of integrating vision and action at the foveal scale. Beyond that, SC visual responses themselves are strongly modulated, and in multiple ways, by the occurrence of small eye movements. Intriguingly, this impact can extend to eccentricities well beyond the fovea, causing both sensitivity enhancement and suppression in the periphery. Because of large foveal magnification of neural tissue, such long-range eccentricity effects are neurally warped into smaller differences in anatomical space, providing a structural means for linking peripheral and foveal visual modulations around fixational eye movements. Finally, even the retinal-image visual flows associated with tiny fixational eye movements are signaled fairly faithfully by peripheral SC neurons with relatively large receptive fields. These results demonstrate how studying active vision at the foveal scale represents an opportunity for understanding primate vision during natural behaviors involving ever-present foveating eye movements.
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Sally, Sharon L., and Rick Gurnsey. "Foveal and extra-foveal orientation discrimination." Experimental Brain Research 183, no. 3 (July 18, 2007): 351–60. http://dx.doi.org/10.1007/s00221-007-1048-3.
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Weldon, Kimberly, Alexandra Woolgar, Anina Rich, and Mark Williams. "The fovea is essential for peripheral vision: The effect of foveal distractors on extra-foveal perception." Journal of Vision 15, no. 12 (September 1, 2015): 609. http://dx.doi.org/10.1167/15.12.609.
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Mäkelä, P., R. Näsänen, and J. Rovamo. "Identifying Facial Images in the Visual Periphery." Perception 26, no. 1_suppl (August 1997): 279. http://dx.doi.org/10.1068/v970073.
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Identification sensitivity for four different faces was measured at the fovea and in the periphery to find out whether foveal and peripheral visual performance in this complex spatial task can be made equivalent simply by changing image magnification. Identification sensitivity was measured as a function of image magnification. The lowest contrast for identification was determined by a 4AFC method. Observers indicated via the keyboard which of the four faces was presented on the CRT screen. The images were shown monocularly at the fovea and at 2.5, 5, and 10 deg eccentricities in the nasal visual field of the right eye (eccentricity measured from the right- hand edge of the image). If scaling is successful, the foveal and peripheral sensitivity vs size functions collapse together when shifted along the size dimension only (Watson, 1987 Journal of the Optical Society of America A4 1579). Although the foveal and peripheral sensitivity functions could be superimposed, they did not fully superimpose without also shifting them in vertical direction, as foveal sensitivity at largest sizes was slightly superior to that of any eccentric location. Thus, size scaling alone was not adequate for this task, in agreement with the contrast sensitivity results of Valeton and Watson (1990 Perception19 Supplement, 393). In this identification task, performance deteriorated towards the periphery at approximately the same rate as visual acuity, when the size corresponding to half-maximal sensitivity at each eccentricity was used as a measure.
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AHMAD, KAREEM M., KARL KLUG, STEVE HERR, PETER STERLING, and STAN SCHEIN. "Cell density ratios in a foveal patch in macaque retina." Visual Neuroscience 20, no. 2 (March 2003): 189–209. http://dx.doi.org/10.1017/s0952523803202091.
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We examine the assumptions that the fovea contains equal numbers of inner (invaginating or ON) and outer (flat or OFF) midget bipolar cells and equal numbers of inner and outer diffuse bipolar cells. Based on reconstruction from electron photomicrographs of serial thin sections through the fovea of a macaque monkey, we reject both assumptions. First, every foveal L and M cone is presynaptic to one inner and one outer midget bipolar cell; however, S cones are presynaptic to one outer but no inner midget bipolar cell. Second, we measure the density of all foveal cells in the same patch of fovea, affording accurate cell density ratios. For each foveal cone pedicle, at a density of 26,500 mm−2, there is close to one (0.88) outer diffuse bipolar cell but only 0.40 inner diffuse bipolar cells. This asymmetry may be related to differences in resolution and sensitivity for light increments and decrements. We also find one (1.01) Müller cell, one (1.01) amacrine cell in the inner nuclear layer, and close to one (0.83) horizontal cell for each cone pedicle. In addition, for each S cone, there are two inner S-cone bipolar cells and two small bistratified ganglion cells. In total, there are 3.4 cone bipolar cells per cone but only 2.6 ganglion cells per cone. The latter ratio is enough to accommodate one midget ganglion cell for each midget bipolar cell.
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Battaglia Parodi, Maurizio, Pierluigi Iacono, Alexandros Papayannis, Giorgio Alto, Alessio Buzzotta, Alessandro Arrigo, Maria Vittoria Cicinelli, and Francesco Bandello. "Near-infrared fundus autofluorescence in early age-related macular degeneration." European Journal of Ophthalmology 30, no. 6 (October 29, 2019): 1448–53. http://dx.doi.org/10.1177/1120672119885047.
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Purpose: To describe the patterns on near-infrared fundus autofluorescence in eyes affected by early age-related macular degeneration. Design: Cross-sectional observational case series. Participants: A total of 84 eyes of 84 patients suffering from early age-related macular degeneration (>63 μm but <125 μm drusen and no-to-mild retinal pigment epithelium abnormalities) were enrolled. Methods: Patients underwent best-corrected visual acuity, biomicroscopy, infrared reflectance, short-wavelength fundus autofluorescence, and near-infrared fundus autofluorescence. Eyes were classified according to different patterns of near-infrared fundus autofluorescence. Main outcome was definition of relative prevalence and features of each near-infrared fundus autofluorescence pattern; secondary outcomes were correlation between near-infrared fundus autofluorescence and short-wavelength fundus autofluorescence and between near-infrared fundus autofluorescence patterns and best-corrected visual acuity. Results: Four different patterns of near-infrared fundus autofluorescence identified: normal foveal signal (Pattern A, 7%); normal foveal signal with hyperautofluorescent/hypoautofluorescent spots not involving the fovea (Pattern B, 65.5%); hyperautofluorescent/hypoautofluorescent spots involving the fovea (Pattern C, 15.5%); patchy pattern (Pattern D, 12%). best-corrected visual acuity was lower in eyes with foveal signal alteration (Patterns C and D). Conclusion: Near-infrared fundus autofluorescence pattern in early age-related macular degeneration might be suggestive of visual function deterioration when the fovea is involved. Longitudinal studies are warranted to confirm our preliminary results.
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Sjöstrand, Johan, and Zoran Popović. "Structural consequences of arrested foveal development in preterms with persisting signs of immaturity." Eye 34, no. 6 (October 23, 2019): 1077–85. http://dx.doi.org/10.1038/s41433-019-0627-4.
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Abstract Purpose To evaluate the impact of structural changes in a limited sample of adult preterms with foveal immaturity from optical coherence tomography (OCT) B-scan images and to estimate layer displacement and changes in areal and volume magnification within the inner fovea. Subjects and methods Layer thickness was measured in conventional and directional OCT scans from eight preterms with different degrees of foveal immaturity (24–33 weeks of gestation, 22–33 years of age) and five controls (20–33 years of age). We obtained reflectivity profiles of the outer plexiform layer (OPL) and manual segmentation data of the inner nuclear layer (INL) and the combined ganglion cell layer (GCL) and inner plexiform layer (IPL) at specified eccentricities from 300 to 900 µm. Displacement of cumulative thickness curves of preterms compared with that of the controls was used to estimate retardation of layer displacement. Changes in areal magnification and layer thickness were used to construct a structural model of redistribution within the fovea of preterms. Results Retardation of centrifugal layer displacement of OPL and all inner retinal layers (IRL) was marked in both preterm groups with foveal immaturity, whereas retardation was marginal in the preterm group without clinical signs of immaturity. Retarded displacement within the IRL and OPL had a major impact on available space within the central fovea. Conclusions A marked retardation of displacement was demonstrated for all IRL within the immature fovea of preterms with decreased areal and volume magnification and reduced space available for synaptic communication coupled to the degree of immaturity.
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Motamedi, Seyedamirhosein, Frederike C. Oertel, Sunil K. Yadav, Ella M. Kadas, Margit Weise, Joachim Havla, Marius Ringelstein, et al. "Altered fovea in AQP4-IgG–seropositive neuromyelitis optica spectrum disorders." Neurology - Neuroimmunology Neuroinflammation 7, no. 5 (June 23, 2020): e805. http://dx.doi.org/10.1212/nxi.0000000000000805.
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ObjectiveTo investigate disease-specific foveal shape changes in patients with neuromyelitis optica spectrum disorders (NMOSDs) using foveal morphometry.MethodsThis cross-sectional study included macular spectral domain optical coherence tomography scans of 52 eyes from 28 patients with aquaporin-4 immunoglobulin G (AQP4-IgG)-seropositive NMOSD, 116 eyes from 60 patients with MS, and 123 eyes from 62 healthy controls (HCs), retrospectively, and an independent confirmatory cohort comprised 33/33 patients with NMOSD/MS. The fovea was characterized using 3D foveal morphometry. We included peripapillary retinal nerve fiber layer (pRNFL) thickness and combined macular ganglion cell and inner plexiform layer (GCIPL) volume to account for optic neuritis (ON)-related neuroaxonal damage.ResultsGroup comparison showed significant differences compared with HC in the majority of foveal shape parameters in NMOSD, but not MS. Pit flat disk area, average pit flat disk diameter, inner rim volume, and major slope disk length, as selected parameters, showed differences between NMOSD and MS (p value = 0.017, 0.002, 0.005, and 0.033, respectively). This effect was independent of ON. Area under the curve was between 0.7 and 0.8 (receiver operating characteristic curve) for discriminating between NMOSD and MS. Pit flat disk area and average pit flat disk diameter changes independent of ON were confirmed in an independent cohort.ConclusionsFoveal morphometry reveals a wider and flatter fovea in NMOSD in comparison to MS and HC. Comparison to MS and accounting for ON suggest this effect to be at least in part independent of ON. This supports a primary retinopathy in AQP4-IgG–seropositive NMOSD.
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Potier, Simon, Mindaugas Mitkus, Francesco Bonadonna, Olivier Duriez, Pierre-François Isard, Thomas Dulaurent, Marielle Mentek, and Almut Kelber. "Eye Size, Fovea, and Foraging Ecology in Accipitriform Raptors." Brain, Behavior and Evolution 90, no. 3 (2017): 232–42. http://dx.doi.org/10.1159/000479783.
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Birds with larger eyes are predicted to have higher spatial resolution because of their larger retinal image. Raptors are well known for their acute vision, mediated by their deep central fovea. Because foraging strategies may demand specific visual adaptations, eye size and fovea may differ between species with different foraging ecology. We tested whether predators (actively hunting mobile prey) and carrion eaters (eating dead prey) from the order Accipitriformes differ in eye size, foveal depth, and retinal thickness using spectral domain optical coherence tomography and comparative phylogenetic methods. We found that (1) all studied predators (except one) had a central and a temporal fovea, but all carrion eaters had only the central fovea; (2) eye size scaled with body mass both in predators and carrion eaters; (3) predators had larger eyes relative to body mass and a thicker retina at the edge of the fovea than carrion eaters, but there was no difference in the depth of the central fovea between the groups. Finally, we found that (4) larger eyes generally had a deeper central fovea. These results suggest that the visual system of raptors within the order Accipitriformes may be highly adapted to the foraging strategy, except for the foveal depth, which seems mostly dependent upon the eye size.
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Wu, Jing, Sebastian M. Waldstein, Alessio Montuoro, Bianca S. Gerendas, Georg Langs, and Ursula Schmidt-Erfurth. "Automated Fovea Detection in Spectral Domain Optical Coherence Tomography Scans of Exudative Macular Disease." International Journal of Biomedical Imaging 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/7468953.
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In macular spectral domain optical coherence tomography (SD-OCT) volumes, detection of the foveal center is required for accurate and reproducible follow-up studies, structure function correlation, and measurement grid positioning. However, disease can cause severe obscuring or deformation of the fovea, thus presenting a major challenge in automated detection. We propose a fully automated fovea detection algorithm to extract the fovea position in SD-OCT volumes of eyes with exudative maculopathy. The fovea is classified into 3 main appearances to both specify the detection algorithm used and reduce computational complexity. Based on foveal type classification, the fovea position is computed based on retinal nerve fiber layer thickness. Mean absolute distance between system and clinical expert annotated fovea positions from a dataset comprised of 240 SD-OCT volumes was 162.3 µm in cystoid macular edema and 262 µm in nAMD. The presented method has cross-vendor functionality, while demonstrating accurate and reliable performance close to typical expert interobserver agreement. The automatically detected fovea positions may be used as landmarks for intra- and cross-patient registration and to create a joint reference frame for extraction of spatiotemporal features in “big data.” Furthermore, reliable analyses of retinal thickness, as well as retinal structure function correlation, may be facilitated.
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Ghoshal, Rituparna, Sharanjeet Sharanjeet-Kaur, Norliza Mohamad Fadzil, Somnath Ghosh, NorFariza Ngah, and Roslin Azni Abd Aziz. "Baseline Optical Coherence Tomography Parameters That May Influence 6 Months Treatment Outcome of Polypoidal Choroidal Vasculopathy Eyes with Combination Therapy: A Short-Term Pilot Study." International Journal of Environmental Research and Public Health 18, no. 10 (May 18, 2021): 5378. http://dx.doi.org/10.3390/ijerph18105378.
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Although optical coherence tomography (OCT) parameters have assisted in the diagnosis of polypoidal choroidal vasculopathy (PCV), its potential to evaluate treatment outcomes has not been established. The purpose of this pilot study was to evaluate baseline OCT parameters that may influence treatment outcome in PCV eyes with combination therapy. In this single-centered, prospective study, patients were recruited with at least one treatment-naïve PCV eye and treated with combination therapy of intravitreal anti-vascular endothelial growth factor and photodynamic therapy. Best-corrected distance and near visual acuity (DVA and NVA), and contrast sensitivity (CS) were recorded at baseline and six months after treatment. OCT parameters were determined. Twenty-six eyes of 26 patients aged between 51 to 83 years were evaluated. In eyes that had disrupted external limiting membrane (ELM), photoreceptors inner and outer segment (IS-OS) junction at 1000 micron of fovea at baseline showed low mean visual functions after 6 months of treatment. Eyes with foveal sub-retinal fluid (SRF) and polyp at central 1000 micron of fovea at baseline showed significantly worse DVA and CS after six months. Thus, the presence of foveal SRF, foveal polyp, disrupted ELM, and IS-OS junction at baseline significantly influenced the six months’ visual outcome in PCV eyes treated with combination therapy.
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Currant, Hannah, Pirro Hysi, Tomas W. Fitzgerald, Puya Gharahkhani, Pieter W. M. Bonnemaijer, Anne Senabouth, Alex W. Hewitt, et al. "Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images." PLOS Genetics 17, no. 5 (May 12, 2021): e1009497. http://dx.doi.org/10.1371/journal.pgen.1009497.
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Optical Coherence Tomography (OCT) enables non-invasive imaging of the retina and is used to diagnose and manage ophthalmic diseases including glaucoma. We present the first large-scale genome-wide association study of inner retinal morphology using phenotypes derived from OCT images of 31,434 UK Biobank participants. We identify 46 loci associated with thickness of the retinal nerve fibre layer or ganglion cell inner plexiform layer. Only one of these loci has been associated with glaucoma, and despite its clear role as a biomarker for the disease, Mendelian randomisation does not support inner retinal thickness being on the same genetic causal pathway as glaucoma. We extracted overall retinal thickness at the fovea, representative of foveal hypoplasia, with which three of the 46 SNPs were associated. We additionally associate these three loci with visual acuity. In contrast to the Mendelian causes of severe foveal hypoplasia, our results suggest a spectrum of foveal hypoplasia, in part genetically determined, with consequences on visual function.
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ATZEI, A. "New trends in arthroscopic management of type 1-B TFCC injuries with DRUJ instability." Journal of Hand Surgery (European Volume) 34, no. 5 (July 20, 2009): 582–91. http://dx.doi.org/10.1177/1753193409100120.
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Advances in radiocarpal and distal radioulnar joint (DRUJ) diagnostic arthroscopy permits a treatment-oriented classification of triangular fibrocartilage complex (TFCC) peripheral tears: 1) repairable distal tears; 2) repairable complete tears; 3) repairable proximal tears; 4) non-repairable tears; and 5) tears associated with DRUJ arthritis. Class 1 tears should be sutured; Class 2 and 3 are associated with DRUJ instability and require TFCC reattachment to the fovea; Class 4 tears need reconstruction using a tendon graft and Class 5 tears require an arthroplasty. Arthroscopic assisted TFCC foveal reattachment is possible through the direct foveal portal, a dedicated DRUJ working portal. Arthroscopic TFCC reconstruction using a tendon graft showed promising results.
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Pelli, Denis G., Sarah J. Waugh, Marialuisa Martelli, Sebastian J. Crutch, Silvia Primativo, Keir X. Yong, Marjorie Rhodes, et al. "A clinical test for visual crowding." F1000Research 5 (January 19, 2016): 81. http://dx.doi.org/10.12688/f1000research.7835.1.
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Crowding is a major limitation of visual perception. Because of crowding, a simple object, like a letter, can only be recognized if clutter is a certain critical spacing away. Crowding is only weakly associated with acuity. The critical spacing of crowding is lowest in the normal fovea, and grows with increasing eccentricity in peripheral vision. Foveal crowding is more prominent in certain patient groups, including those with strabismic amblyopia and apperceptive agnosia. Crowding may lessen with age during childhood as reading speed increases. The range of crowding predicts much of the slowness of reading in children with developmental dyslexia. There is tantalizing evidence suggesting that the critical spacing of crowding indicates neural density (participating neurons per square deg) in the visual cortex. Thus, for basic and applied reasons, it would be very interesting to measure foveal crowding clinically in children and adults with normal and impaired vision, and to track the development of crowding during childhood. While many labs routinely measure peripheral crowding as part of their basic research in visual perception, current tests are not well suited to routine clinical testing because they take too much time, require good fixation, and are mostly not applicable to foveal vision. Here we report a new test for clinical measurement of crowding in the fovea. It is quick and accurate, works well with children and adults, and we expect it to work well with dementia patients as well. The task is to identify a numerical digit, 1-9, using a new “Pelli” font that is identifiable at tiny width (0.02 deg, about 1 minarc, in normal adult fovea). This allows quick measurement of the very small (0.05 deg) critical spacing in the normal adult fovea, as well as with other groups that have higher critical spacing. Preliminary results from healthy adults and children are presented.
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Folk, James C. "Foveal Cysts." Archives of Ophthalmology 116, no. 9 (September 1, 1998): 1177. http://dx.doi.org/10.1001/archopht.116.9.1177.
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Sánchez-Vicente, José L., Miguel Contreras-Díaz, Laura Llerena-Manzorro, Trinidad Rueda, Fernando López-Herrero, Fredy E. Molina-Socola, Ana Muñoz-Morales, and Enrique Rodríguez de la Rúa-Franch. "FOVEAL HYPOPLASIA." Retinal Cases & Brief Reports 12, no. 2 (2018): 122–26. http://dx.doi.org/10.1097/icb.0000000000000440.
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FRY, GLENN A. "Foveal Photopigments." Optometry and Vision Science 69, no. 6 (June 1992): 417–22. http://dx.doi.org/10.1097/00006324-199206000-00001.
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Durrani, Asad F., and Mark W. Johnson. "Foveal Tuft." Retina 41, no. 7 (July 2021): e47-e48. http://dx.doi.org/10.1097/iae.0000000000003201.
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Tuten, William S., and Wolf M. Harmening. "Foveal vision." Current Biology 31, no. 11 (June 2021): R701—R703. http://dx.doi.org/10.1016/j.cub.2021.03.097.
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Matziridi, Maria, Mijke O. Hartendorp, Eli Brenner, and Jeroen B. J. Smeets. "Does Perisaccadic Compression Require Foveal Vision?" Perception 43, no. 11 (January 1, 2014): 1214–24. http://dx.doi.org/10.1068/p7666.
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People make systematic errors when localizing a stimulus that is presented briefly near the time of a saccade. These errors have been interpreted as compression towards the position that is fixated after the saccade. Normally, fixating a position means that its image falls on the fovea. Macular degeneration (MD) damages the central retina, obliterating foveal vision. Many people with MD adopt a new retinal locus for fixation, called the preferred retinal locus (PRL). If the compression of space during the saccade is a special characteristic of the fovea, possibly due to the high density of cones that is found in the fovea, one might expect people lacking central vision to show no compression of space around the time of a saccade. If the compression of space during the saccade is related to the position that is fixated after the saccade, one would expect compression towards the PRL, despite the lack of a high density of cones in this area. We found that a person with MD showed a clear compression towards her PRL. We conclude that perisaccadic compression is related to the position that is fixated after the saccade rather than to the high density of receptors in the fovea.
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Wu, Kun-Chao, Ji-Neng Lv, Hui Yang, Feng-Mei Yang, Rui Lin, Qiang Lin, Ren-Juan Shen, et al. "Nonhuman Primate Model of Oculocutaneous Albinism with TYR and OCA2 Mutations." Research 2020 (March 11, 2020): 1–11. http://dx.doi.org/10.34133/2020/1658678.
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Human visual acuity is anatomically determined by the retinal fovea. The ontogenetic development of the fovea can be seriously hindered by oculocutaneous albinism (OCA), which is characterized by a disorder of melanin synthesis. Although people of all ethnic backgrounds can be affected, no efficient treatments for OCA have been developed thus far, due partly to the lack of effective animal models. Rhesus macaques are genetically homologous to humans and, most importantly, exhibit structures of the macula and fovea that are similar to those of humans; thus, rhesus macaques present special advantages in the modeling and study of human macular and foveal diseases. In this study, we identified rhesus macaque models with clinical characteristics consistent with those of OCA patients according to observations of ocular behavior, fundus examination, and optical coherence tomography. Genomic sequencing revealed a biallelic p.L312I mutation in TYR and a homozygous p.S788L mutation in OCA2, both of which were further confirmed to affect melanin biosynthesis via in vitro assays. These rhesus macaque models of OCA will be useful animal resources for studying foveal development and for preclinical trials of new therapies for OCA.
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Lavidor, Michal, and Vincent Walsh. "A Magnetic Stimulation Examination of Orthographic Neighborhood Effects in Visual Word Recognition." Journal of Cognitive Neuroscience 15, no. 3 (April 1, 2003): 354–63. http://dx.doi.org/10.1162/089892903321593081.
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The split-fovea theory proposes that visual word recognition is mediated by the splitting of the foveal image, with letters to the left of fixation projected to the right hemisphere (RH) and letters to the right of fixation projected to the left hemisphere (LH). We applied repetitive transcranial magnetic stimulation (rTMS) over the left and right occipital cortex during a lexical decision task to investigate the extent to which word recognition processes could be accounted for according to the split-fovea theory. Unilateral rTMS significantly impaired lexical decision latencies to centrally presented words, supporting the suggestion that foveal representation of words is split between the cerebral hemispheres rather than bilateral. Behaviorally, we showed that words that have many orthographic neighbors sharing the same initial letters (“lead neighbors”) facilitated lexical decision more than words with few lead neighbors. This effect did not apply to end neighbors (orthographic neighbors sharing the same final letters). Crucially, rTMS over the RH impaired lead-, but not end-neighborhood facilitation. The results support the split-fovea theory, where the RH has primacy in representing lead neighbors of a written word.
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Sacconi, Riccardo, Enrico Borrelli, Eleonora Corbelli, Luigi Capone, Alessandro Rabiolo, Adriano Carnevali, Marco Casaluci, et al. "Quantitative changes in the ageing choriocapillaris as measured by swept source optical coherence tomography angiography." British Journal of Ophthalmology 103, no. 9 (October 25, 2018): 1320–26. http://dx.doi.org/10.1136/bjophthalmol-2018-313004.
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AimTo analyse quantitative optical coherence tomography angiography (OCTA) parameters of choriocapillaris (CC) at the foveal, perifoveal and parafoveal regions in healthy subjects of different age.MethodsIn this observational cross-sectional study, consecutive healthy subjects underwent swept source OCTA (PLEX Elite 9000, Carl Zeiss Meditec, USA). 3×3 mm and 6×6 mm scans centred on the fovea were acquired analysed and postprocessed with thresholding and binarisation processes. The main outcome measures included CC quantitative OCTA features (perfusion density (PD), vessel length density (VLD) and vessel diameter index (VDI)) at the foveal, perifoveal and parafoveal regions, and their relationship with age.ResultsSeventy-two eyes (72 patients, mean age 47.4±19.2 years, mean axial length 24.0±0.7 mm) were included. The mean PD was statistically lower in the foveal region compared with the parafoveal region in 3×3 mm scans (p=0.009). In subjects aged 70–80, PD of the foveal region was significantly reduced compared with the perifoveal region in 6×6 mm scans (p=0.008). A strong negative correlation was found between PD and ageing in the foveal, parafoveal and perifoveal regions (p<0.001 in all analyses). Furthermore, PD in the nasal-perifoveal region was significantly lower than the temporal-perifoveal region (p=0.005). No significant correlation was found between VLD and age in all regions, whereas VDI was strictly correlated with age (p<0.001).ConclusionsWe reported in vivo a strong negative correlation between PD and ageing in the CC of healthy subjects. This reduction seems related to a reduced diameter, and not to a reduced number, of capillaries. The age-related changes were higher in the central area compared with the perifoveal area.