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Journal articles on the topic 'Accommodation of the lens'

Author: Grafiati

Published: 4 June 2021

Last updated: 10 February 2022

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1

Li, Jin, Qi Chen, Zhibo Lin, Lin Leng, Fang Huang, and Ding Chen. "The Predictability of Preoperative Pilocarpine-Induced Lens Shift on the Outcomes of Accommodating Intraocular Lenses Implanted in Senile Cataract Patients." Journal of Ophthalmology 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/6127130.

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Purpose. To evaluate the predictability of lens shift induced by pilocarpine (LSPilo) on the outcomes of accommodating intraocular lens (Acc-IOL) implantation.Methods. Twenty-four eyes of 24 senile cataract patients who underwent phacoemulsification and Acc-IOL implantation were enrolled.LSPilowas evaluated with anterior segment optical coherence tomography (AS-OCT). At 3 months postoperatively, the best corrected distance visual acuities (BCDVA), distance-corrected near visual acuities (DCNVA), and subjective and objective accommodations were measured. IOL shifts under accommodation stimulus (IOLSAcc) were evaluated with AS-OCT.Results. The meanLSPilowas 112.29 ± 30.72 µm.LSPilowas not associated with any preoperative parameters. The meanIOLSAccwas 130.46 ± 42.71 µm. The mean subjective and objective accommodation were 1.54 ± 0.39 D and 1.27 ± 0.41 D, respectively. The mean postoperative BCDVA and DCNVA (log MAR value) were 0.22 ± 0.11 and 0.24 ± 0.12, respectively.LSPilopositively correlated withIOLSAcc(r=0.541;P=0.006), subjective accommodation (r=0.412;P=0.022), and objective accommodation (r=0.466;P=0.045), respectively.Conclusion.LSPilois an independent preoperative parameter associated with the postoperative Acc-IOL mobility and pseudophakic accommodation. It may offer valuable information for ophthalmologists in determining the suitable candidates for Acc-IOL implantation.

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2

Zhang, Wen-Wen, and Zheng-Gao Xie. "Advances in the Study of Lens Refilling." Journal of Ophthalmology 2020 (August 26, 2020): 1–10. http://dx.doi.org/10.1155/2020/8956275.

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The ultimate goal of cataract surgery is to restore the accommodation while restoring distance visual acuity. Different kinds of accommodative intraocular lens (IOLs) and surgical techniques have been suggested to apply during the surgery, but they showed poor postoperative accommodation. It is possible to achieve this goal by refilling the lens with an injectable polymer. We present a summary of the existing materials, methods, results, and some obstacles in clinical application that remain of lens refilling for restoration of accommodation. Two main problems have restricted the clinical application of this technique. One was the formation of postoperative secondary capsule opacification and the other was the different accommodative power after surgery.

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3

Gibson, George, Fiona Cruickshank, James Wolffsohn, and Leon Davies. "Optical Coherence Tomography Reveals Sigmoidal Crystalline Lens Changes during Accommodation." Vision 2, no. 3 (August 21, 2018): 33. http://dx.doi.org/10.3390/vision2030033.

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This study aimed to quantify biometric modifications of the anterior segment (AS) during accommodation and to compare them against changes in both accommodative demand and response. Thirty adults, aged 18–25 years were rendered functionally emmetropic with contact lenses. AS optical coherence tomography (AS-OCT) images were captured along the 180° meridian (Visante, Zeiss Meditec, Jena, Germany) under stimulated accommodative demands (0–4 D). Images were analysed and lens thickness (LT) was measured, applying a refractive index correction of 1.00. Accommodative responses were also measured sequentially through a Badal optical system fitted to an autorefractor (Shin Nippon NVision-K 5001, Rexxam, Japan). Data were compared with Dubbelman schematic eye calculations. Significant changes occurred in LT, anterior chamber depth (ACD), lens centroid (i.e., ACD + LT/2), and AS length (ASL = ACD + LT) with accommodation (all p < 0.01). There was no significant change in CT with accommodation (p = 0.81). Measured CT, ACD, and lens centroid values were similar to Dubbelman modelled parameters, however AS-OCT overestimated LT and ASL. As expected, the accommodative response was less than the demand. Interestingly, up until approximately 1.5 D of response (2.0 D demand), the anterior crystalline lens surface appears to be the primary correlate. Beyond this point, the posterior lens surface moves posteriorly resulting in an over-all sigmoidal trajectory. he posterior crystalline lens surface demonstrates a sigmoidal response with increasing accommodative effort.

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Croft, Mary Ann, Paul L. Kaufman, Kathryn S. Crawford, Michael W. Neider, Adrian Glasser, and Laszlo Z. Bito. "Accommodation dynamics in aging rhesus monkeys." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 275, no. 6 (December 1, 1998): R1885—R1897. http://dx.doi.org/10.1152/ajpregu.1998.275.6.r1885.

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Accommodation, the mechanism by which the eye focuses on near objects, is lost with increasing age in humans and monkeys. This pathophysiology, called presbyopia, is poorly understood. We studied aging-related changes in the dynamics of accommodation in rhesus monkeys aged 4–24 yr after total iridectomy and midbrain implantation of an electrode to permit visualization and stimulation, respectively, of the eye’s accommodative apparatus. Real-time video techniques were used to capture and quantify images of the ciliary body and lens. During accommodation in youth, ciliary body movement was biphasic, lens movement was monophasic, and both slowed as the structures approached their new steady-state positions. Disaccommodation occurred more rapidly for both ciliary body and lens, but with longer latent period, and slowed near the end point. With increasing age, the amplitude of lens and ciliary body movement during accommodation declined, as did their velocities. The latent period of lens and ciliary body movements increased, and ciliary body movement became monophasic. The latent period of lens and ciliary body movement during disaccommodation was not significantly correlated with age, but their velocity declined significantly. The age-dependent decline in amplitude and velocity of ciliary body movements during accommodation suggests that ciliary body dysfunction plays a role in presbyopia. The age changes in lens movement could be a consequence of increasing inelasticity or hardening of the lens, or of age changes in ciliary body motility.

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5

Marran, Lynn, and Clifton M. Schor. "Lens induced aniso-accommodation." Vision Research 38, no. 22 (November 1998): 3601–19. http://dx.doi.org/10.1016/s0042-6989(98)00064-9.

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6

Schachar, Ronald A. "Assessing intraocular lens accommodation." Journal of Cataract & Refractive Surgery 32, no. 5 (May 2006): 702–4. http://dx.doi.org/10.1016/j.jcrs.2006.01.051.

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7

Wang, Yuanyuan, Yilei Shao, and Yimin Yuan. "Simultaneously measuring ocular aberration and anterior segment biometry during accommodation." Journal of Innovative Optical Health Sciences 08, no. 02 (March 2015): 1550005. http://dx.doi.org/10.1142/s1793545815500054.

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In the human eye, accommodation is essential for functional vision. However, the mechanisms regulating accommodation and the ocular parameters affecting aberrations remain to be explored. In order to measure the alterations of ocular aberration and crystalline lens biometry during dynamic accommodative stimuli, we designed an optical coherence tomography with ultra-long penetration depth (UL-OCT) combined with a Shack–Hartmann wavefront sensor (SHWFS). This integrated set up measures human eye's anterior segment as well as monochromatic high-order aberrations (HOAs) with 6 μm resolution and (1/20) λ accuracy. A total of 10 healthy volunteers without ocular diseases were examined. Upon exposure to accommodative stimuli, the wavefront aberrations became larger. Among the anterior segment biometry, the anterior crystalline lens demonstrated significant curvature during accommodation and was the major cause of high-order aberration. These findings suggest that the front surface of the crystalline lens can significantly affect variation among aberrations, which is a key factor underlying the quality of human vision.

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8

Gerometta, R., A. C. Zamudio, D. P. Escobar, and O. A. Candia. "Volume change of the ocular lens during accommodation." American Journal of Physiology-Cell Physiology 293, no. 2 (August 2007): C797—C804. http://dx.doi.org/10.1152/ajpcell.00094.2007.

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During accommodation, mammalian lenses change shape from a rounder configuration (near focusing) to a flatter one (distance focusing). Thus the lens must have the capacity to change its volume, capsular surface area, or both. Because lens topology is similar to a torus, we developed an approach that allows volume determination from the lens cross-sectional area (CSA). The CSA was obtained from photographs taken perpendicularly to the lenticular anterior-posterior (A-P) axis and computed with software. We calculated the volume of isolated bovine lenses in conditions simulating accommodation by forcing shape changes with a custom-built stretching device in which the ciliary body-zonulae-lens complex (CB-Z-L) was placed. Two measurements were taken (CSA and center of mass) to calculate volume. Mechanically stretching the CB-Z-L increased the equatorial length and decreased the A-P length, CSA, and lens volume. The control parameters were restored when the lenses were stretched and relaxed in an aqueous physiological solution, but not when submerged in oil, a condition with which fluid leaves the lens and does not reenter. This suggests that changes in lens CSA previously observed in humans could have resulted from fluid movement out of the lens. Thus accommodation may involve changes not only in capsular surface but also in volume. Furthermore, we calculated theoretical volume changes during accommodation in models of human lenses using published structural parameters. In conclusion, we suggest that impediments to fluid flow between the aquaporin-rich lens fibers and the lens surface could contribute to the aging-related loss of accommodative power.

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9

Zhang, Junna, Yang Ni, Peng Li, Wen Sun, Mengyun Liu, Dongyu Guo, and Chixin Du. "Anterior Segment Biometry with Phenylephrine and Tropicamide during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography." Journal of Ophthalmology 2019 (February 25, 2019): 1–5. http://dx.doi.org/10.1155/2019/6827215.

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Purpose. To investigate the influence of phenylephrine and tropicamide on anterior segment biometry with ultralong scan depth optical coherence tomography (UL-OCT) during accommodation. Methods. In this study, 20 left eyes of healthy volunteers with a mean ± standard deviation age of 31.05 ± 5.84 years and a mean refraction of −1.16 ± 1.11 diopters (range 0∼−3.0 D) were imaged using UL-OCT after instillation of artificial tears, phenylephrine, and tropicamide in three follow-up trials, respectively. At each follow-up trial, two repeated measurements were performed at states of relax and 5D accommodative stimulation. The dimensional parameters included central corneal thickness (CCT), anterior chamber depth (ACD), pupil diameter (PD), lens thickness (LT), and horizontal radii of the lens anterior and posterior surface curvatures (LAC and LPC). Results. Tropicamide led to larger pupil, deeper ACD, thinner LT, and flatter crystalline lens surface (P<0.05). Phenylephrine induced an increase in PD (P<0.05), while no significant changes were seen in ACD, LT, LAC, and LPC (P>0.05). CCT did not change after both phenylephrine and tropicamide instillation in this study (P>0.05). Tropicamide induced the loss of accommodation and phenylephrine achieved pupil dilation without affecting the accommodation. PD, ACD decreased, LT increased significantly and the anterior and posterior surface of the lens in a 6.294 mm of diameter optical zone became steeper during accommodation after administration of phenylephrine (P<0.05). Conclusion. The anterior segment physiology changed after tropicamide instillation. Besides, tropicamide induced the loss of accommodation and phenylephrine preserved the accommodation with a larger pupil. And, the anterior and posterior surface of lens in a 6.294 mm of diameter optical zone became steeper during the accommodation.

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10

Ruan, Xiaoting, Zhenzhen Liu, Lixia Luo, and Yizhi Liu. "The Structure of the Lens and Its Associations with the Visual Quality." BMJ Open Ophthalmology 5, no. 1 (September 2020): e000459. http://dx.doi.org/10.1136/bmjophth-2020-000459.

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In humans, the lens is the organ with the ability to change morphology and refractive power, designated as accommodation, to focus light from various distances and obtain clear retinal image. The accommodative ability of the lens depends on its structure and biological parameters. The lens grows throughout the life, forming specific lens sutures and a unique gradient refractive index, and possesses regenerative ability under certain circumstances. Minimally invasive lens surgery that preserves endogenous lens epithelial stem/progenitor cells (LECs) can achieve functional lens regeneration in humans. The lens is the main source of intraocular aberration, especially intraocular higher-order aberrations (IHOAs) which is found to be binocularly symmetrical in phakic eyes. There is a compensation mechanism between corneal aberrations and lens aberrations. Therefore, the structure and the biological parameters of the lens, the binocular relationship of the lens and the correlation between the lens and cornea affect visual quality. This paper summarises the above findings and their current and potential applications in refractive surgeries, providing a comprehensive understanding of the lens as a strong determinant of visual quality in the optical system.

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11

Weale, R. A. "The Accommodation of Lens Implants." Ophthalmic Research 37, no. 3 (2005): 156–58. http://dx.doi.org/10.1159/000086169.

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12

Ben-nun, Joshua, and Jorge L. Alió. "Reply: Assessing intraocular lens accommodation." Journal of Cataract & Refractive Surgery 32, no. 5 (May 2006): 704–5. http://dx.doi.org/10.1016/j.jcrs.2006.01.056.

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13

Nishi, Yutaro, Kamiar Mireskandari, Peng Khaw, and Oliver Findl. "Lens refilling to restore accommodation." Journal of Cataract & Refractive Surgery 35, no. 2 (February 2009): 374–82. http://dx.doi.org/10.1016/j.jcrs.2008.10.054.

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14

Kaluzny, B. J. "Anterior Movement of the Crystalline Lens in the Process of Accommodation in Children." European Journal of Ophthalmology 17, no. 4 (July 2007): 515–20. http://dx.doi.org/10.1177/112067210701700406.

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Purpose To investigate changes of crystalline lens position during accommodation in children with emmetropia, myopia, and hyperopia. Methods A total of 188 children (372 eyes) from 4 to 19 years old (mean age 11.3±4.43) with cycloplegic refractive error within a range +9.00 D to −9.00 D were enrolled. After a general ophthalmic examination, ultrasound biometry was performed, with the eye at a maximal accommodative effort. Cycloplegia was induced by triple installation of 1% tropicamide drops and 30 minutes later the biometric examination was repeated. Results In emmetropic eyes in the process of accommodation, the anterior pole of the crystalline lens moved forward by 0.144±0.14 mm (p ≤ 0.001); the position of the posterior pole did not change. In myopic eyes, the anterior pole moved forward by 0.071±0.13 mm (p≤0.001) and the posterior pole moved backward by 0.039±0.10 mm (p=0.003). In hyperopic eyes, the whole lens translocated anteriorly: anterior pole moved forward by 0.242±0.16 mm (p≤ 0.001) and posterior pole moved forward by 0.036±0.09 mm (p≤0.001). Differences among emmetropia, myopia, and hyperopia were statistically significant. Forward movement of the posterior pole correlated with a low axial length of the eye, and also with plus refractive error and with a smaller accommodative increase of lens thickness. Conclusions In children, accommodative changes of the crystalline lens position depend on refractive status.

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15

Farouk, Mahmoud Mohamed, Takeshi Naito, Kayo Shinomiya, Hiroshi Eguchi, Khulood Mohammed Sayed, Toshihiko Nagasawa, Takashi Katome, and Yoshinori Mitamura. "Optical Coherence Tomography Reveals New Insights into the Accommodation Mechanism." Journal of Ophthalmology 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/510459.

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Purpose. To evaluate the movement of the anterior and posterior lens poles during naturally stimulated accommodation in children using anterior segment optical coherence tomography (OCT).Methods. This is a prospective, observational, noncomparative case series including 18 eyes of nine children. Analysis of the anterior segment in the accommodated and unaccommodated state (with cycloplegia) was done using anterior segment OCT. The main outcome measures were the position of the anterior and posterior lens poles (in relation to the cornea) and lens thickness (LT).Results. A Statistically significant forward movement of the anterior lens pole and backward movement of the posterior lens pole with an increase in LT were found during accommodation (P<0.001). There was no significant difference between the degree of movement of the anterior lens pole and the posterior lens pole during accommodation (P=0.944).Conclusions. Anterior segment OCT provides a rapid noncontact method for studying accommodation in children. The backward movement of the posterior lens pole during accommodation nearly equals the forward movement of its anterior pole. These data minimize the theoretical hydraulic effect of the vitreous during accommodation, adding more support to the capsular theory of Helmholtz.

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Neveu, Charles F., and Lawrence W. Stark. "The Virtual Lens." Presence: Teleoperators and Virtual Environments 7, no. 4 (August 1998): 370–81. http://dx.doi.org/10.1162/105474698565785.

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We describe a new type of feedback display based upon ocular accommodation, called the virtual lens, that maintains a focused projection of a CRT image on the retina independent of changes in accommodation, and that replaces the optical image-processing action of the crystalline lens with an arbitrary computable image transform. We describe some applications of the virtual lens in visual psychophysics and virtual environments.

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Zhang, Y., L. E. Mays, and P. D. Gamlin. "Characteristics of near response cells projecting to the oculomotor nucleus." Journal of Neurophysiology 67, no. 4 (April 1, 1992): 944–60. http://dx.doi.org/10.1152/jn.1992.67.4.944.

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1. Previous work has shown neurons just dorsal and lateral to the oculomotor nucleus that increase their firing rate with increases in the angle of ocular convergence. It has been suggested that the output of these midbrain near response cells might provide the vergence command needed by the medial rectus motoneurons. However, lens accommodation ordinarily accompanies convergence, and a subsequent study showed that only about one-half of these midbrain near response cells carried a signal related exclusively to vergence. One hypothesis suggested by this finding is that this subgroup of neurons might have a unique role in providing a "pure" vergence signal to the medial rectus motoneurons. 2. In the present study extracellular recordings were made from midbrain near response cells in monkeys while eye position and lens accommodation were measured. The monkeys viewed targets through an optical system that allowed the accommodative and ocular vergence demands to be manipulated independently. This approach was used to produce a partial dissociation of accommodative and vergence responses, so that an accommodative and vergence coefficient could be determined for each cell, by the use of the following equation FR = R0 + kda x AR + kdv x CR where FR is the firing rate of the near response cell, R0 is the predicted firing rate for a distant target, kda is the (dissociated) accommodation coefficient, AR is the accommodative response, kdv is the (dissociated) vergence coefficient, and CR is the convergence response. 3. The vergence and accommodation coefficients were determined for a large number of midbrain near response cells, including a subset that could be antidromically activated from the medial rectus subdivisions of the oculomotor nucleus. Some near response neurons were found with signals related exclusively to convergence (i.e., kdv greater than 0 and kda = 0), whereas several others had signals related exclusively to lens accommodation (i.e., kda greater than 0 and kdv = 0). The majority of the near response cells had signals related to both responses (i.e., kda not equal to 0 and kdv not equal to 0). Furthermore, the vergence and accommodation coefficients of near response cells appeared to be continuously distributed. Some cells had negative accommodation or vergence coefficients. 4. The 17 near response cells that could be antidromically activated from the oculomotor nucleus presumably provide vergence signals to the medial rectus motoneurons. Although all had positive vergence coefficients, only four of these cells carried signals that were related exclusively to vergence.(ABSTRACT TRUNCATED AT 400 WORDS)

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Koretz, Jane F., Christopher A. Cook, and Paul L. Kaufman. "Aging of the human lens: changes in lens shape upon accommodation and with accommodative loss." Journal of the Optical Society of America A 19, no. 1 (January 1, 2002): 144. http://dx.doi.org/10.1364/josaa.19.000144.

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Schachar, R. A., C. Tello, D. P. Cudmore, J. M. Liebmann, T. D. Black, and R. Ritch. "In vivo increase of the human lens equatorial diameter during accommodation." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 271, no. 3 (September 1, 1996): R670—R676. http://dx.doi.org/10.1152/ajpregu.1996.271.3.r670.

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The movement of the human lens equator during accommodation was examined in vivo. High-resolution ultrasound images of the lens equator were obtained from young human subjects whose amplitude of accommodation was controlled with 1% tropicamide and 2% pilocarpine. To avoid errors that otherwise arise from eye rotation or other movement, the cornea and sclera were used as positional references in comparative studies of the video images obtained from the unaccommodated and accommodated states. During accommodation, the movement at the lens equator involved small displacement; i.e., < 100 microns, and the equator did not move anteriorly or posteriorly but peripherally toward the sclera. These results indicate that the lens equator is under increased zonular tension during accommodation, in contradiction to Helmholtz's widely accepted theory of accommodation.

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Zamudio, Aldo C., Oscar A. Candia, Chi Wing Kong, Brian Wu, and Rosana Gerometta. "Surface change of the mammalian lens during accommodation." American Journal of Physiology-Cell Physiology 294, no. 6 (June 2008): C1430—C1435. http://dx.doi.org/10.1152/ajpcell.90623.2007.

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Classical theories suggest that the surface area of the crystalline lens changes during accommodation while the lens volume remains constant. Our recent work challenged this view by showing that the lens volume decreases as the lens flattens during unaccommodation. In this paper we investigate 1) the magnitude of changes in the surface of the in vitro isolated cow lens during simulated accommodation, as well as that of human lens models, determined from lateral photographs and the application of the first theorem of Pappus; and 2) the velocity of the equatorial diameter recovery of prestretched cow and rabbit lenses by using a custom-built software-controlled stretching apparatus synchronized to a digital camera. Our results showed that the in vitro cow lens surface changed in an unexpected manner during accommodation depending on how much tension was applied to flatten the lens. In this case, the anterior surface initially collapsed with a reduction in surface followed by an increase in surface, when the stretching was applied. In the human lens model, the surface increased when the lens unaccommodated. The lens volume always decreases as the lens flattens. An explanation for the unexpected surface change is presented and discussed. Furthermore, we determined that the changes in lens volume, as reflected by the speed of the equatorial diameter recovery in in vitro cow and rabbit lenses during simulated accommodation, occurred within a physiologically relevant time frame (200 ms), implying a rapid movement of fluid to and from the lens during accommodation.

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Hassan, Sadiq, Philips I. Ebisike, Christopher O. Timothy, Basheer A. Z. Chedi, Rabi Y. Sani, and Saudat G. Habib. "Accommodative-Convergence Mechanism failure in HIV-Positive Non Presbyopic Patient on Highly Active Anti-Retroviral Therapy: A case report." Journal of the Nigerian Optometric Association 22, no. 1 (August 14, 2020): 44–50. http://dx.doi.org/10.4314/jnoa.v22i1.7.

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Purpose: Accommodative-convergence mechanism failure could occur in non presbyopic HIV- sero positive patients on Highly Active Anti-Retroviral Therapy (HAART). This could be due to either direct neuronal infection by HIV, pathologic changes of the lens or the ciliary body or adverse effects of some individual drugs constituting the HAART regimen on the cranial nerves which play vital roles in the mechanism of accommodation and convergence. Case report: This is a case report of an accommodative- convergence mechanism failure in HIV positive non presbyopic 32-year-old male patient that was on HAART for more than five years. He presented with distance visual acuity (VA) of OD: 6/9 +2, OS: 6/9, and near visual acuity (NVA) of N24 both eyes, 3Δ esophoria at distance and 4Δ esophoria at near. Amplitude of accommodation (AA) was 3.50D and accommodative convergence/accommodation (AC/A) ratio was 6/1. Following comprehensive evaluation, his refractive correction was OD: Plano/-0.50DC X 180 6/5 and OS: Plano/-0.50DC X 90 6/5 at distance with near addition (Add) 2.50D N5. This was prescribed for regular wear in form of D-Top bifocal lens. Conclusion: These findings showed that HIV sero-positive adults on HAART could develop accommodativeconvergence mechanism failure, which may be characterized by low amplitude of accommodation, receded near point of convergence and high non presbyopic reading addition. These conditions may be under-recognized and need for reading addition of a non presbyopic age is often overlooked. Key Words: Accommodative-Convergence, HIV, Lateral Phoria, Refractive error.

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Buckhurst, Phillip J., Shehzad A. Naroo, and Sunil Shah. "Advanced Intraocular Lens Designs." European Ophthalmic Review 04, no. 01 (2010): 82. http://dx.doi.org/10.17925/eor.2010.04.01.82.

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Intraocular lenses (IOLs) have evolved since their introduction and spherical monofocal designs are no longer the only pseudophakic option. IOLs with a toric surface are able to correct astigmatism, but are dependent on the accuracy of placement. Haptic design is very important with toric IOLs as different designs demonstrate different post-operative rotational stability. Multifocal IOLs produce multiple focal points within the eye and so provide the capacity for simultaneous distance and near vision. Various mechanisms for creating these focal points exist, which determine how light is distributed. Accommodating IOLs use the optic shift principle in order to restore the accommodative response. Single and dual optic variations exist; however, the restoration of accommodation has been limited and variable with the current generation of these IOLs. Aspherical IOLs are designed to improve the optical quality of the image created by the IOL. Aspherical correcting IOLs are dependent on their centration and tilt. New phacoemulsification technology allows cataract removal through a sub-2mm incision, and microincisional IOLs can be implanted through these incisions, which results in minimal surgical impact on the cornea. Blue- and violet-blocking IOLs have been introduced, which might help prevent the development of age-related macular degeneration. Light-adjustable lenses are a relatively new technology and allow non-invasive post-operative adjustment of the IOL’s refractive power. This is a fast-moving area of research and development due to the high demands of clinical practice.

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Sokolowska, Anna, and Frank Thorn. "DOES ACCOMMODATION ALTER CRYSTALLINE LENS POSITION?" Optometry and Vision Science 79, Supplement (December 2002): 219. http://dx.doi.org/10.1097/00006324-200212001-00414.

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Chien, Chang-Hai M., Tseng Huang, and Ronald A. Schachar. "A Model for Crystalline Lens Accommodation." Comprehensive Therapy 29, no. 2-3 (2003): 166–75. http://dx.doi.org/10.1385/comp:29:2-3:166.

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Chien, Chang-Hai M., Tseng Huang, and Ronald A. Schachar. "A model for crystalline lens accommodation." Comprehensive Therapy 29, no. 2-3 (June 2003): 166–75. http://dx.doi.org/10.1007/s12019-003-0020-9.

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26

Travers, M. "Lens fibre shape changes in accommodation." Ophthalmic and Physiological Optics 6, no. 2 (1986): 246. http://dx.doi.org/10.1016/0275-5408(86)90027-x.

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Chien, Chang-Hai M., Tseng Huang, and Ronald A. Schachar. "Analysis of human crystalline lens accommodation." Journal of Biomechanics 39, no. 4 (January 2006): 672–80. http://dx.doi.org/10.1016/j.jbiomech.2005.01.017.

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West, J. A., J. G. Sivak, and M. J. Doughty. "Functional morphology of lenticular accommodation in the young chicken (Gallus domesticus)." Canadian Journal of Zoology 69, no. 8 (August 1, 1991): 2183–93. http://dx.doi.org/10.1139/z91-305.

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The morphology of the accommodative apparatus in chicks has not been fully characterized, and the accommodative mechanism is not well understood. A detailed study of the ciliary muscle and ciliary process morphology in newly hatched and 2-week-old chicks has been carried out in this investigation. The methods include light microscopy and scanning and transmission electron microscopy. Accommodation is induced with nicotine sulphate in young chicks to compare the morphology of the accommodative apparatus in a relaxed and accommodated state. This study confirms the striated nature of the ciliary muscle in the developing chick eye and the direct articulation of the ciliary processes with the annular pad of the lens. The muscle fibers of the nicotine-treated eyes are shorter than those of the control eyes and appear contracted. Quantitatively, the fibers of the nicotine-treated eyes have a significantly shorter sarcomere length than control eye muscle fibers. The ciliary folds of the nicotine-treated eyes are very convoluted and are significantly shorter in length than control eye folds. Evidence from this investigation suggests that the contraction of the ciliary muscle causes the ciliary folds to exert direct force onto the annular pad of the lens during accommodation.

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Stokkermans, Thomas J., Jeremy C. Reitinger, George Tye, Chiu-Yen Kao, Sangeetha Ragupathy, Huachun A. Wang, and Carol B. Toris. "Accommodative Exercises to Lower Intraocular Pressure." Journal of Ophthalmology 2020 (December 18, 2020): 1–7. http://dx.doi.org/10.1155/2020/6613066.

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Purpose. This study investigated how a conscious change in ocular accommodation affects intraocular pressure (IOP) and ocular biometrics in healthy adult volunteers of different ages. Methods. Thirty-five healthy volunteers without ocular disease or past ocular surgery, and with refractive error between −3.50 and +2.50 diopters, were stratified into 20, 40, and 60 year old (y.o.) age groups. Baseline measurements of central cornea thickness, anterior chamber depth, anterior chamber angle, cornea diameter, pupil size, and ciliary muscle thickness were made by autorefraction and optical coherence tomography (OCT), while IOP was measured by pneumotonometry. Each subject’s right eye focused on a target 40 cm away. Three different tests were performed in random order: (1) 10 minutes of nonaccommodation (gazing at the target through lenses that allowed clear vision without accommodating), (2) 10 minutes of accommodation (addition of a minus 3 diopter lens), and (3) 10 minutes of alternating between accommodation and nonaccommodation (1-minute intervals). IOP was measured immediately after each test. A 20-minute rest period was provided between tests. Data from 31 subjects were included in the study. ANOVA and paired t-tests were used for statistical analyses. Results. Following alternating accommodation, IOP decreased by 0.7 mmHg in the right eye when all age groups were combined ( p = 0.029). Accommodation or nonaccommodation alone did not decrease IOP. Compared to the 20 y.o. group, the 60 y.o. group had a thicker ciliary muscle within 75 μm of the scleral spur, a thinner ciliary muscle at 125–300 μm from the scleral spur, narrower anterior chamber angles, shallower anterior chambers, and smaller pupils during accommodation and nonaccommodation ( p ’s < 0.01). Conclusion. Alternating accommodation, but not constant accommodation, significantly decreased IOP. This effect was not lost with aging despite physical changes to the aging eye. A greater accommodative workload and/or longer test period may improve the effect.

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Langenbucher, Achim, Stefan Huber, Nhung X. Nguyen, Berthold Seitz, Gabriele C. Gusek-Schneider, and Michael Küchle. "Measurement of accommodation after implantation of an accommodating posterior chamber intraocular lens." Journal of Cataract & Refractive Surgery 29, no. 4 (April 2003): 677–85. http://dx.doi.org/10.1016/s0886-3350(02)01893-x.

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Nishi, Okihiro, Yutaro Nishi, Shiao Chang, and Kayo Nishi. "Accommodation amplitudes after an accommodating intraocular lens refilling procedure: In vivo update." Journal of Cataract & Refractive Surgery 40, no. 2 (February 2014): 295–305. http://dx.doi.org/10.1016/j.jcrs.2013.06.028.

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Küchle, Michael, Berthold Seitz, Achim Langenbucher, Peter Martus, and Nhung X. Nguyen. "Stability of refraction, accommodation, and lens position after implantation of the 1CU accommodating posterior chamber intraocular lens." Journal of Cataract & Refractive Surgery 29, no. 12 (December 2003): 2324–29. http://dx.doi.org/10.1016/s0886-3350(03)00413-9.

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Mitsukawa, Tadahiro, Yumi Suzuki, Yosuke Momota, Shun Suzuki, and Masakazu Yamada. "Effects of 0.01% Atropine Instillation Assessed Using Swept-Source Anterior Segment Optical Coherence Tomography." Journal of Clinical Medicine 10, no. 19 (September 25, 2021): 4384. http://dx.doi.org/10.3390/jcm10194384.

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In this paper, we assessed the short-term effects of 0.01% atropine eye drops on anterior segment parameters by performing ocular biometry using a swept-source anterior segment optical coherence tomography system (AS-OCT). We recruited 17 healthy volunteers (10 men and 7 women aged 24–35 years) with no history of eye disease. Participants without accommodative demand demonstrated significant mydriasis 1 h after the atropine instillation (4.58 ± 0.77 to 5.41 ± 0.83 mm). Pupil diameters with a 5 diopter (D) accommodative stimulus at 1 h (4.70 ± 1.13 mm) and 24 h (4.05 ± 1.06 mm) after atropine instillation were significantly larger than those at baseline (3.71 ± 0.84 mm). Barring pupil diameter, no other biometric parameters significantly changed at any point in time after atropine instillation without accommodative demand. However, with an accommodative stimulus, anterior chamber depth (ACD) at 1 h and posterior curvature of the lens at 1 and 24 h were both significantly larger than those before atropine instillation. Using AS-OCT, we detected a slight decrease in the accommodation response of ocular biometric components evoked by 0.01% atropine instillation. Morphologically, our measurements suggested a change in the ACD and horizontal radius of the lens’ posterior surface curvatures due to the subtle reduction of accommodation.

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Obstfeld, Henri. "Crystalline lens accommodation and anterior chamber depth." Ophthalmic and Physiological Optics 9, no. 1 (January 1989): 36–40. http://dx.doi.org/10.1111/j.1475-1313.1989.tb00802.x.

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CHUPROV, A., Y. KUDRYAVTSEVA, and V. KUDRYAVTSEV. "Hardness of a crystalline lens and accommodation." Acta Ophthalmologica 87 (September 2009): 0. http://dx.doi.org/10.1111/j.1755-3768.2009.3346.x.

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Abolmaali, A., R. A. Schachar, and T. Le. "Sensitivity study of human crystalline lens accommodation." Computer Methods and Programs in Biomedicine 85, no. 1 (January 2007): 77–90. http://dx.doi.org/10.1016/j.cmpb.2006.08.005.

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37

Planten, J. Th. "Age and the lens ? refraction and accommodation." Documenta Ophthalmologica 67, no. 1-2 (1987): 53–57. http://dx.doi.org/10.1007/bf00142697.

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Lee, Min Jae, Sang-Yeob Kim, Byeong-Yeon Moon, Dong-Sik Yu, and Hyun Gug Cho. "Change Amplitude of Accommodation and Lens Adaptation after Adding Spherical Lens." Korean Journal of Vision Science 19, no. 3 (September 30, 2017): 275–81. http://dx.doi.org/10.17337/jmbi.2017.19.3.275.

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Marussich, Lauren, Fabrice Manns, Derek Nankivil, Bianca Maceo Heilman, Yue Yao, Esdras Arrieta-Quintero, Arthur Ho, Robert Augusteyn, and Jean-Marie Parel. "Measurement of Crystalline Lens Volume During Accommodation in a Lens Stretcher." Investigative Opthalmology & Visual Science 56, no. 8 (July 1, 2015): 4239. http://dx.doi.org/10.1167/iovs.15-17050.

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40

Lin, J. T. "New Formulas Comparing the Accommodation in Human Lens and Intraocular Lens." Journal of Refractive Surgery 21, no. 2 (March 1, 2005): 200–201. http://dx.doi.org/10.3928/1081-597x-20050301-19.

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41

Myagkov, Alexander, and Pavel Karamyshev. "Revisiting the influence of accommodation and accommodation disorders on the process of development and progression of myopia (literature review)." Eye 22, no. 129 (March 2020): 34–43. http://dx.doi.org/10.33791/2222-4408-2020-1-34-43.

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Purpose. To analyze domestic and foreign scientific publications over the past 5 years, reflecting the issues of accommodation and accommodation disorders. To assess the presence or absence of changes in the classification of accommodation disorders. To evaluate the role of various accommodation disorders in the development and progression of myopia. Relevance. Given the significant increase in the number of people with myopia in recent decades, interest in the study of accommodation and accommodation disorders has increased again. This is due not only to the fact that accommodative insufficiency (AI, weak accommodation), is considered one of the leading factors in the development of myopia, but also because the use of one or another method of myopia control affects the process of accommodation, increasing or reducing accommodation reserves, affecting the functioning of the binocular system. New developments in the field of visualization of intraocular structures (anterior segment imaging by OCT, Sheimpflug imaging, UBM) allows carry out previously impossible studies of changes in the crystalline lens, ciliary body, at different levels of accommodation response, in different age groups in vivo, which itself affects the development and testing of new concepts related to the mechanism of the accommodation. Thus, the dynamics of the changes that are taking place motivates ophthalmologists to take a fresh look at the already established concepts of the accommodation mechanism, to assess the consistency of previously adopted approaches to the classification of accommodation disorders, which in turn can affect changes in the tactics of myopia control, which is especially crucial as myopization of the population, especially in children, is accelerating every day. Our task was to evaluate domestic and foreign scientific publications over the past 5 years, reflecting the results of studies of the accommodation mechanism, assessing the influence of accommodation disorders on the progression of myopia. The task was also to assess the prospect of creating a unified classification of accommodative disturbances, the ability to create a unified algorithm for controlling progression, based on accommodation parameters. Search strategy. A review of English and Russian sources related to the study of the mechanism of accommodation was conducted; the effect of accommodation disorders on the progression of myopia and their classification was studied using the following databases: PubMed, Cyberleninka, Google scholar, Elibrary. The search depth was 5 years (2014-2019), excluding the historical sources. The sources included: - original research; - historical issue, scanned publications; - studies / descriptions of accommodation disorders and their relationship with myopia; - abstracts and full-text publications; - literary reviews; - monographies. The exclusion criteria were: - themed issues with closed or restricted access. During the process of searching and processing information, the data obtained were not systematized according to the level of reliability due to the fact that the purpose of the review is to obtain a general idea of the views on this issue, assess the presence or absence of unity in the formation of diagnostic criteria, without the task of suggesting practical recommendations. The following search queries were made to search the databases: a) English-language sources - mechanism of accommodation, accommodation AND history issue, accommodation AND Helmholtz AND Tsherning, accommodation AND myopia, accommodation AND myopia control AND myopia progression, accommodation disorders OR accommodation anomalies, accommodative excess AND accommodative infacility AND accommodative insufficiency, epidemiology myopia AND etiology myopia, near work AND myopia AND children; b) Russian-language sources - the history of the study of accommodation, the mechanism of accommodation, classification of accommodation disorders, accommodation, accommodation disorders with myopia, accommodation and the progression of myopia, weakness of accommodation, habitual excess tension of accommodation; progressive myopia, myopia control.

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Nguyen, Nhung X., B. Seitz, S. Reese, A. Langenbucher, and M. K�chle. "Accommodation after Nd: YAG capsulotomy in patients with accommodative posterior chamber lens 1CU." Graefe's Archive for Clinical and Experimental Ophthalmology 243, no. 2 (December 14, 2004): 120–26. http://dx.doi.org/10.1007/s00417-004-1041-5.

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43

Sitka, M. M., S. G. Bodrova, and N. A. Pozdeyeva. "The Effectiveness of Different Optical Correction Methods in Children and Adolescents with Progressive Myopia Based on a Comparative Evaluation of the Accommodation and Axial Length of Eyes." Ophthalmology in Russia 15, no. 2S (July 28, 2018): 65–72. http://dx.doi.org/10.18008/1816-5095-2018-2s-65-72.

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Objective: to determine optimal method of progressive myopia optical correction in children and adolescents.Patients and methods. Conducted 5-year prospective clinical and instrumental examination of 494 children with myopia using orthokeratology lenses, soft contact lenses and glasses. 61 children (the average age 11.7 ± 2.36 years) with myopia –2.87 ± 1.1 D and astigmatism –0.58 ± 0.27 D used orthokeratological lens. 92 children (the average age 12.8 ± 1.51 years) with myopia –3.66 ± 1.07 D, astigmatism –0.53 ± 0.18 D wore soft contact lens. 79 children (the average age 11.52 ± 1.78 years) with myopia –1.59 ± 1.08 D, astigmatism –0.71 ± 0.54 D used glasses with monofocal lenses, with full correction. The control group consisted of 249 children (the average age 9.1 ± 1.14 years) with initial emmetropia. Determination of refraction, subjective and objective determination of accommodation, and axial length of the eye (“IOL-master”) was conducted in children.Results. The maximum progression of myopia was observed in younger children (8–9 years). Correction of myopia with orthokeratology lenses (OKLs) was accompanied by the lowest dynamics of changes in axial length (axial elongation 0,44 ± 0,32 mm) compared to the correction with soft contact lenses (SCLs) (axial elongation 0,73 ± 0,36 mm), spectacle correction (axial elongation 1,39 ± 0,47 mm) and the control group (axial elongation 0,6 ± 0,41 mm). In all children with myopia, at the beginning of the study, there were reduced values reserve of relative accommodation and an objective accommodative response. Correction of myopia with OKLs (p = 0,0002) and SCLs (p = 0,036) provides the normalization of subjective and objective reserve indication of relative accommodation in both age group in comparison of spectacles correction.Conclusion. Correction with orthokeratology lens in children with progressive myopia contributes to the minimum growth length of the eye. Correction of myopia OKLs and MKL improves of subjective and objective indicators of relative accommodation reserve.

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Andison, M. E., and J. G. Sivak. "The functional morphology of the retractor lentis muscle of a teleost fish, Astronotus ocellatus." Canadian Journal of Zoology 72, no. 11 (November 1, 1994): 1880–86. http://dx.doi.org/10.1139/z94-256.

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Visual teleost species such as the oscar, Astronotus ocellatus, accommodate by moving the lens within the eye. This movement is controlled by a smooth muscle, the retractor lentis. We observed two components in the accommodative lens movement: a nasotemporal and a mediolateral component. In the present study, the anatomical basis of these two components was investigated. Photographs of freshly dissected specimens were used to determine the position and relative size of the retractor lentis muscle in situ. Light microscopy sections reveal two fibre orientations within the muscle. Scanning electron micrographs illustrate that the muscle ligament fans out in two primary directions where it inserts into the lens capsule. The observation that two independent lens movements occur during accommodation is supported anatomically by the orientation of the fibres within the muscle and by the nature of the insertion of the ligament into the lens capsule.

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Gomes, Jessica, and Sandra Franco. "Crystalline lens imaging during accommodation with a slit-scanning tomography system: preliminary results." EPJ Web of Conferences 238 (2020): 12015. http://dx.doi.org/10.1051/epjconf/202023812015.

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A slit-scanning tomography system previously developed in the Centre of Physics of University of Minho allows to capture images of the eye and posteriorly calculus of the biometric (thickness and curvature) and optical (wavefront aberrations) properties of the corneal and crystalline lens surfaces. It is intended to optimise the system for an accurate computing of these properties of the crystalline lens in the relaxed state and during ocular accommodation. In this study, preliminary experimental results of the crystalline lens imaging of a subject during accommodation are presented.

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IWASAKI, Tsuneto, Kenji IBI, and Shinobu AKIYA. "VDT work and eye-dominance in lens accommodation." Japanese journal of ergonomics 34, Supplement (1998): 346–47. http://dx.doi.org/10.5100/jje.34.supplement_346.

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Takeda, Tsunehiro, Hiroshi Endo, and Keizo Hashimoto. "1604 Accommodation related MEG in human lens cotrol." Neuroscience Research 28 (January 1997): S205. http://dx.doi.org/10.1016/s0168-0102(97)90560-5.

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Qiao, Wen, Frank S. Tsai, Sung Hwan Cho, Huimin Yan, and Yu-Hwa Lo. "Fluidic Intraocular Lens With a Large Accommodation Range." IEEE Photonics Technology Letters 21, no. 5 (March 2009): 304–6. http://dx.doi.org/10.1109/lpt.2008.2010779.

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Schachar, Ronald A., and Guojun G. Liao. "Ocular lens does not change volume during accommodation." American Journal of Physiology-Cell Physiology 293, no. 5 (November 2007): C1727—C1728. http://dx.doi.org/10.1152/ajpcell.00266.2007.

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May, Paul J., and Paul D. Gamlin. "Is Primate Lens Accommodation Unilaterally or Bilaterally Controlled?" Investigative Opthalmology & Visual Science 61, no. 8 (July 7, 2020): 5. http://dx.doi.org/10.1167/iovs.61.8.5.

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