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Severinsky, Boris. "Silicone Hydrogel Miniscleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia." International Journal of Keratoconus and Ectatic Corneal Diseases 3, no. 3 (2014): 127–29. http://dx.doi.org/10.5005/jp-journals-10025-1092.
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ABSTRACT Purpose To report successful visual rehabilitation of post refractive surgery keratoectasia shortly after corneal collage crosslinking (CXL) procedure achieved with silicone hydrogel mini-scleral (SHmS) contact lens. Materials and methods A 29-year-old woman attended to our clinic with complaints on decreased vision in her left eye. Twelve years earlier she underwent bilateral laser-assisted in situ keratomileusis (LASIK) procedure for myopia correction. Corneal topography revealed bilateral central keratoectasia with maximal keratometry values of 55.4 Diopter (D) for her right eye and 59.7 D for the left, corneal thicknesses were 422 and 443 respectively. The patient underwent an uneventful CXL procedure in her left eye and was fitted with SHmS lens 5 weeks later. The lens was designed to rest over the patients’ sclera and perilimbal cornea and vault the central cornea with minimal support over it. Results SHmS lens fitting resulted in significant subjective improvement in visual acuity (from 20/200, unaided to 20/25, contact lens corrected). The patient was able to wear the lens upto 10 hours a day with stable contact lens corrected vision. No contact lens related complications, such as edema or neovascularization were observed during 3 months follow-up period. As a result of successful restoration of vision in the CXL-treated eye, the patient was scheduled for the procedure in her other eye. Conclusion SHmS contact lens should be considered as an option for the visual rehabilitation of corneas shortly after collagen corneal crosslinking procedure. This novel contact lens modality made from flexible and highly gas permeable material minimizes contact lens influence on corneal recovery after CXL and provides an excellent visual outcome. How to cite this article Severinsky B. Silicone Hydrogel Mini-scleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia. Int J Kerat Ect Cor Dis 2014;3(3):127-129.
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Kaluzny, Bartlomiej J., Joanna Stachura, Patryk Mlyniuk, Alfonso Jimenez-Villar, Magdalena Wietlicka-Piszcz, and Ireneusz Grulkowski. "Change in the geometry of positive- and negative-powered soft contact lenses during wear." PLOS ONE 15, no. 11 (2020): e0242095. http://dx.doi.org/10.1371/journal.pone.0242095.
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Contact lens wear causes mutual interactions between the ocular surface and the lens, which may affect comfort as well as vision. The aim of this study was to examine deformations in modern positive- and negative-powered silicone hydrogel soft contact lenses (SiH SCLs) after 7 days of continuous wear. This pre-post interventional study included 64 eyes: 42 eyes with myopia of -3.00 D and 22 eyes with hyperopia of +3.00 D. All patients underwent general ophthalmic examination, corneal topography/tomography, total corneal and epithelial thickness mapping, and specular microscopy before and after the wearing period. SiH SCLs made of senofilcon A were worn continuously for 7 days on all eligible eyes. The geometry of the new and used lenses was measured 3 to 6 minutes after removal in two perpendicular planes using a custom-made swept source optical coherence tomography (SS-OCT) system for in vitro measurements. The anterior and posterior radii of curvature decreased in -3.00 D lenses in two perpendicular planes. This effect correlated significantly with average keratometry of the cornea. Sagittal lens height was lower in +3.00 D lens after wear, which correlated moderately with the corneal sagittal height. A significant decrease in central corneal epithelial thickness was observed after wearing +3.0 D lenses. In conclusion, SiH SCLs made of senofilcon A undergo minor deformations after 7-day continuous wear. Geometry modifications are different for -3.00 D and +3.00 D lenses, and they imitate the shape of the anterior eye surface. These geometric changes are accompanied by a decrease in the central thickness of corneal epithelium after +3.00 D lens wear.
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Ozkurt, Yelda, Mehmet Atakan, Tugba Gencaga, and Sezen Akkaya. "Contact Lens Visual Rehabilitation in Keratoconus and Corneal Keratoplasty." Journal of Ophthalmology 2012 (2012): 1–4. http://dx.doi.org/10.1155/2012/832070.
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Keratoconus is the most common corneal distrophy. It’s a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.
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Belousova, Elena. "OKVision® Onefit™ Mini-Scleral Lenses Fitting Guide." Eye 127, no. 2019-3 (2019): 47–52. http://dx.doi.org/10.33791/2222-4408-2019-3-47-52.
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Corneal topography has been widely used in medical practice over recent years and it has helped to detect keratectasias of various genesis more often and in the earlier stages. The emergence of the new polymer materials with high oxygen permeability made it possible to wear scleral contact lenses safely, that also resulted in their popularization. Scleral gas permeable lenses are an effective method of vision correction not only for various ectasias, but also for ametropia, presbyopia and other refractive pathologies. Scleral contact lenses do not directly touch the cornea and the limbus area, whereas tear firm under the lens physically smoothes out all of the existing defects and irregularities of the corneal surface, thus creating a ”cornea-tear-lens“ unified optical system. As a result, visual acuity increases significantly. In addition, scleral lenses ensure excellent comfort starting from the first minutes of wearing due to a larger diameter, no direct contact with the cornea and relatively low mobility. Scleral lenses ensure high visual functions and comfort owing to their specific self-supporting design, which is rested on the sclera. Selection and fitting of scleral contact lenses is simple and can be mastered by any ophthalmologist
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DeNaeyer, Gregory. "Profilometry. Using Corneo-scleral topography for scleral lens fitting." Eye 21, no. 128 (2019): 19–22. http://dx.doi.org/10.33791/2222-4408-2019-4-19-22.
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The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.
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Andrienko, G. V. "Visualization and assessment of the anterior surface of the cornea by corneal topography (Part II)." EYE GLAZ 22, no. 3(131) (2020): 43–51. http://dx.doi.org/10.33791/2222-4408-2020-3-43-51.
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Goal. To introduce ophthalmologists and optometrists to the basics of corneal topography. Corneal topography is the main method for assessing corneal surface regularity, the violation of which leads to a deterioration in its refractive properties and a decrease in the quality of vision. The first part of the workshop (The EYE GLAZ. 2020 (22), № 2) presented the main types of topography maps and keratometry data. In the second part, considerations are made regarding mastering the skills of capturing high-quality images and choice of color maps for analysis. Topography patterns as well as topographic signs of keratoconus are also discussed. Conclusion. Placido-based corneal topographers are a useful tool for evaluating the anterior corneal surface, fitting contact lenses and diagnosing keratoconus. Slit-scanning topographers, additionally, are capable of corneal pachymetry and analyzing the posterior surface of the cornea, which allows for carrying out a more detailed assessment and diagnosing keratoconus at preclinical stage.
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Andrienko, Gulnara. "The visualization and assessment of the anterior surface of the cornea using video keratotopography." Eye 22, no. 130 (2020): 36–42. http://dx.doi.org/10.33791/2222-4408-2020-2-36-42.
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Corneal topography is the main method for assessing the regularity of the surface of the cornea. Corneal irregularity leads to a deterioration in its refractive properties and a decrease in the quality of vision. Learning the basics of corneal topography will help determine the choice of a color map for a specific situation, as well as understand and analyze the data associated with these maps. This article describes the main types of topographic maps, various patterns of corneal shape in normal and pathological conditions and how to use the data obtained to design and fit contact lenses. Despite the fact that images may vary depending on topographers used, the information presented in this article is universal.
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Andrienko, Gulnara. "The visualization and assessment of the anterior surface of the cornea using video keratotopography." Eye 22, no. 130 (2020): 36–43. http://dx.doi.org/10.33791/2222-4408-2020-2-36-43.
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Corneal topography is the main method for assessing the regularity of the surface of the cornea. Corneal irregularity leads to a deterioration in its refractive properties and a decrease in the quality of vision. Learning the basics of corneal topography will help determine the choice of a color map for a specific situation, as well as understand and analyze the data associated with these maps. This article describes the main types of topographic maps, various patterns of corneal shape in normal and pathological conditions and how to use the data obtained to design and fit contact lenses. Despite the fact that images may vary depending on topographers used, the information presented in this article is universal.
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Spiteri, Natasha, Anshoo Choudhary, and Stephen Kaye. "Pigmentation of the Cornea Secondary to Tinted Soft Contact Lens Wear." Case Reports in Ophthalmological Medicine 2012 (2012): 1–2. http://dx.doi.org/10.1155/2012/852304.
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Purpose. To report a case of pigmented corneal iron lines following use of tinted soft contact lenses (CL).Methods. A retrospective case report.Results. A 16-year-old girl was referred with suspected CL-related keratopathy OU, having recently switched to tinted soft monthly disposable CLs (8.4/14.0 −3.00 OD, −3.25 OS Aquamarine SofLens Natural Colours, Bausch and Lomb, New York, USA). Both corneas exhibited symmetric superficial corneal pigmented iron lines, which gradually disappeared following discontinuation of CL wear.Conclusions. Pigmented corneal rings have been reported in normal ageing corneas, in certain pathological conditions, and in association with altered corneal topography following LASIK and orthokeratology. We suspect a poorly fitting CL resulted in localised tear pooling between the CL and cornea, and subsequent iron pigment deposition, similar to that seen with orthokeratology. Cosmetic CLs bought via the Internet can be used in an unsupervised manner, with possible impacts on visual function and potential complications.
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Azam, Raisul, Aysworya Mohapatra, and Gaurav Dubey. "Visual Acuity Approach to a Patient with a Rose-K Contact Lens - A Case Report." International Journal of Health Sciences and Research 11, no. 7 (2021): 380–84. http://dx.doi.org/10.52403/ijhsr.20210752.
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Objective- Providing a healthy satisfactory visual acuity approach to a patient of Keratoconus fitted with a Rose-K contact lens. Introduction- Rose K lens is an effective option for visual improvement in irregular cornea such as Keratoconus. Contact lenses are the mainstay therapy for Keratoconus and are the treatment modality of choice in 90% of patients due to corneal surface irregularity. Case History- A 32-year-old female patient visited at Ahooja Eye & Dental Institute, Gurugram, with the chief complaint of diminished vision in her left eye for the last one month. The patient did not complain about diminished vision in the right eye. Earlier, the patient had diagnosed with the case of Keratoconus somewhere else and suggested to be continued with the glasses. The patient had a history of spectacles in the last 7 years and using the current prescription for the last 4 months. Visual acuity for distance & near, with glass and the current prescription was recorded. Conclusion- In our case, after all the presented findings and trial, one pair of Rose K2 lenses of varying total diameter and optic zone diameter was ordered. The patient was asked to visit for lens collection and follow up after 6 months. Lastly, it is advised that all Rose k practitioners keep at least two to three trial lenses, assess the fit in each fit, and choose lenses based on corneal topography. Key words: Rose K Contact Lenses, Keratoconus, Visual Acuity, Topography.
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Bezditko, P. A., та R. A. Parhomets. "Analysis of the Influence of Corneal Parameters on the Pattern of Myopia Progression when Using Orthokeratology Lenses in Children". Ukrainian journal Ophthalmology, № 2(13) (червень 2021): 39–46. http://dx.doi.org/10.30702/ophthalmology30062021-13.2.39-46/17.7-05.
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The progressive course of myopia is one of the most important medical and social problems worldwide. In Ukraine, the relative incidence of moderate myopia ranges from 8.9 to 30.8 % in schoolchildren and in final-year students, mild and moderate myopia is found, according to various data, in 30-68 % of individuals. Some researchers have tried to determine the shape of the cornea and its relationship to the eye size in myopia, but conflicting data have been obtained, so the issue needs further investigation. The aim. To analyze the effect of corneal eccentricity (Ex) in children with myopia on the increase of the axial length of the eye when using orthokeratology lenses (OKL). Methods. The study involved 60 children (117 eyes) aged 7 to 15 years with uncomplicated mild and moderate myopia from –0.75 to –5.0 diopters by spherical equivalent. Biometry was performed using an ultrasound scanner before the start of refractive therapy or prescription of glasses and then every 6 months of observation. Corneal topography was also performed with determination of keratometry and Ex in flat and steep meridians (Oculus Easygraph topographer, Germany). MoonLens OKL with combined design were selected for all the subjects. Results. In patients with mild myopia, there was direct strong correlation between the value of Ex, both in a flat and in a steep meridian, and the axial length at the beginning of the therapy which equaled to 0.28 (p = 0.011) There was also a strong direct relationship between the value of the initial Ex and the difference in refraction (ΔR) after 24 months of observation which equaled to 0.32 (p = 0.001). Assessment of the correlation between the initial value of keratometry and the axial length revealed negative correlation between –0.69 in the group with mild myopia (p<0.001) and –0.67 in children with moderate myopia (p<0.001). There was no correlation of the effect of Ex on the annual gradient of myopia progression in the study. Conclusions. There is no correlation between the baseline Ex and the annual gradient of myopia progression on the background of the use of OKL because the corneal profile changes and there are other factors influencing the pattern of the axial length change. A direct correlation between the baseline Ex and the annual changes in refraction (ΔR) was revealed.
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Ezhova, E. A., I. A. Melikhova, and S. V. Balalin. "Value of Confocal Microscopy of the Cornea in Assessment of the Adaptation Period at Patients with Myopia when Using Orthokeratological Lenses." Ophthalmology in Russia 15, no. 2S (2018): 183–88. http://dx.doi.org/10.18008/1816-5095-2018-2s-183-188.
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Purpose: tо study the histomorphological state of the cornea with the help of confocal microscopy in patients with myopia in the period of adaptation to orthokeratological contact lenses (OCL).Patients and methods. The study of the histomorphological status of the cornea was performed in the central optical, middle peripheral and perilimbal zones using confocal microscopy (ConfoScan-4) in 72 patients (144 eyes) with low myopia (38 people, 76 eyes) and middle myopia (34 persons, 68 eyes) after the appointment of OCL within 1 to 12 months.Results. The maximum significant increase in the degree of epithelial changes in the central optical zone of the cornea was recorded after 7 days of the application of OCL and an increase of nerve fibers activation, the number of activated keratocytes — after 1 month. There were noted the degree of changes in the epithelium, the number of activated keratocytes after 1 month and the degree of activation of nerve fibers after 3 months in the middle peripheral zone of the cornea. At a period of 12 months of the using of OCL in the central optical zone and middle peripheral zone of the cornea the index of the degree of changes in the epithelium, nerve fibers, and the number of activated keratocytes was stabilized. In the perilimbal zone of the cornea the histomorphological parameters did not differ from the initial data at the observation periods, except for innervation. The densities of keratocytes in various layers of the stroma, endothelial cells did not change statistically throughout the study.Conclusions. The results of the histomorphological indices made it possible to single out a “stressful” period of adaptation lasting 1 month, a transitional period of 1 to 3 months and a stable adaptation period, the formation of which was noted after 12 months of the application of OKL. Stable densities of keratocytes in various layers of the corneal stroma, endothelial cells during the entire period of observation indicated a fairly good tolerability of OCL.
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Tikhonova, Olga, Nikolai Pashtaev, Nadezhda Pozdeyeva, et al. "Influence of scleral lenses on visual acuity and aberrations in patients with irregular cornea." Eye 126, no. 2019-2 (2019): 32–39. http://dx.doi.org/10.33791/2222-4408-2019-2-32-39.
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Purpose: To analyze changes of functional parame¬ters and aberrations before fitting and after using rigid gas-permeable scleral lenses (RGPSCL) in patients with irregular cornea. Material and methods. 21 patients (29 eyes) with irregular astigmatism of various etiology were enrolled in this study. The patients could not achieve good visual aсuity in glasses, standard soft or rigid corneal contact lenses. Complex ophthalmologic examination was per¬formed: autorefractometry, visometry, biomicroscopy, computer corneal topography, aberrometry on “OPD-Scan II” (“Nidek”, Japan) before fitting scleral lenses and during the period of their wearing. Results and discussion. The results demonstrat¬ed significant visual acuity improvement after RGP¬SCL fitting in all observed patients. UCVA amounted to 0.1±0.18, BCVA in glasses amounted to 0.4±0.26, BCVA in RGPSCL amounted to 0.7±0.1. An increase of best-corrected visual acuity in RGPSCL was statistically significant in patients after keratoplasty, after intra-stromal corneal ring segments (ICRS) implantation, af¬ter refractive laser surgery (RLS) and in cases of mixed astigmatism. We have found that the correction of ker¬atoconus with the use of RGPSCL resulted in a decrease of the root mean square value (RMS), measured in the 3 mm and 5 mm zones by 2.5 times and 4 times, re¬spectively. In patients wearing RGPSCL after kerato¬plasty, statistically significant decrease in RMS was observed in the 3 mm zone (by 3.85 times) and in the 5 mm zone (by 2.99 times). In patients wearing RGPSCL after implantation of intrastromal corneal ring segment (ICRS), RMS in the 3 mm zone decreased by 1.5 times. In patients wearing RGPSCL after refractive laser surgery (RLS) RMS was 2.5 times lower in the 3 mm zone and 2.8 times lower in the 5 mm zone. In case of mixed astigmatism correction with RGPSCL, RMS increased by 1.6 times in the 3 mm zone and practically did not change in the 5 mm zone. Conclusion. The results obtained demonstrated significant visual acuity improvement in all observed patients. The sub-lens-space filled with tear forms a unified “cornea-tear-scleral contact lens” optic system that corrects unevenness of cornea, decreases amount of high-order aberrations (HOA) and provides a clear stable vision.
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Ermolyuk, Fedor. "Clinical manifestations and diagnosis of keratoconus. Treatment of iatrogenic keratoconus." Spravočnik vrača obŝej praktiki (Journal of Family Medicine), no. 7 (July 1, 2020): 37–42. http://dx.doi.org/10.33920/med-10-2007-05.
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Keratoconus is a dystrophic disease of the cornea, when it is thinned with the formation of a conus-like protrusion (protrusion of the cornea). This disease belongs to the group of keratectasia, it has a multifactorial nature and occurs in approximately 25 % of all corneal pathologies. The disease can be either primary, which is based on dystrophic changes in the cornea, or secondary, which develops against the background of prenatal keratitis. Keratoconus of iatrogenic origin, which develops as a result of refractive eye microsurgery, has become widespread during the last 20 years. Most often primary keratoconus manifests during puberty, progresses to 30–40 years, after which its development slows down. An early clinical manifestation of this corneal pathology is a progressive decrease in visual acuity, development of double vision (binocular diplopia) with the development of a strong headache against this background. Monocular polyopia — images and symbols with multiple contours — develops subsequently. Severe dry eyes, itching, photophobia appear in advanced stages. Diagnosis of keratoconus in some cases can be a significant difficulty, since the use of conventional research methods only allow to suspect refractive errors in the form of myopia or astigmatism. It is necessary to take into account the impossibility of correcting visual impairment using conventional methods — glasses or contact lenses — to make correct diagnosis. As a rule, diagnosis of keratoconus requires use of expanded spectrum of instrumental research methods.
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Knezović, Igor, Mirna Belovari Višnjić, and Hrvoje Raguž. "Late Stage of Corneal Decompensation Caused by Progressive Keratoconus: Can We Treat It and Save the Cornea?" Case Reports in Ophthalmological Medicine 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/795826.
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Aim. To report a case of 40-year-old male with progressive bilateral keratoconus who had undergone transepithelial phototherapeutic keratectomy (TE-PTK) and corneal collagen cross-linking (CXL) using hypoosmolar riboflavin solution in a same day procedure.Methods. Eye examination showed that UCDVA on both eyes was 0,01 according to Snellen charts, and slit lamp biomicroscopy showed paracentral diffuse intrastromal corneal haze. Anterior OCT marked stromal hyperreflective zones and localized paracentral thinning of the cornea. Scheimpflug tomography noted keratoconus stages III-IV on both eyes. After 40/35 microns TE-PTK, a CXL was performed for 30 minutes using hypoosmolar riboflavin solution. The left eye was treated first and the right eye 1 month after. Follow-up period was 10 months.Results. One month after the treatment both eyes showed improvement in corneal topography and the UCDVA was better. Eight months after the treatment BSCVA improved to 0,6 in both eyes using Rose K2 contact lenses and remained stable.Conclusion. TE-PTK and CXL using hypotonic riboflavin solution as a same day procedure have been shown to be a safe and promising method in this case of progressive keratoconus. It was necessary to consider certain parameters that could influence the safety and the final outcome of this combined protocol.
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Seitz, Berthold, Achim Langenbucher, Tobias Hager, Edgar Janunts, Moatasem El-Husseiny, and Nora Szentmáry. "Penetrating Keratoplasty for Keratoconus – Excimer Versus Femtosecond Laser Trephination." Open Ophthalmology Journal 11, no. 1 (2017): 225–40. http://dx.doi.org/10.2174/1874364101711010225.
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Background: In case of keratoconus, rigid gas-permeable contact lenses as the correction method of first choice allow for a good visual acuity for quite some time. In a severe stage of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no more tolerated. In case of existing contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis. Methods: In case of advanced keratoconus – especially after corneal hydrops due to rupture of Descemet’s membrane – penetrating keratoplasty (PKP) still is the surgical method of first choice. Noncontact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in case of “keratoconus recurrences” due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size („as large as possible – as small as necessary“). Limbal centration will be preferred intraoperatively due to optical displacement of the pupil. During the last 10 years femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach. Results: Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces “vertical tilt” and “horizontal torsion” of the graft in the recipient bed, thus resulting in significantly less “all-sutures-out” keratometric astigmatism (2.8 vs. 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. Refractive outcomes of femtosecond laser keratoplasty, however, resemble that of the motor trephine. Conclusions: In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination with intraoperative pitfalls and high postoperative astigmatism.
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Kaiserman, Igor, Lily Karmona, Tzahi Sela, Oz Franco, Avi Shoshani, and Gur Munzer. "Simultaneous Topography-guided Surface Ablation with Collagen Cross-linking for Keratoconus." International Journal of Keratoconus and Ectatic Corneal Diseases 5, no. 2 (2016): 71–76. http://dx.doi.org/10.5005/jp-journals-10025-1124.
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ABSTRACT Purpose In this article, we present the results of eight eyes of patients who underwent combined same-day partial topography-guided surface ablation followed by accelerated collagen cross-linking (CXL) procedure at Care-Vision Laser Centers to achieve stabilization of corneal ectasia and enhance visual rehabilitation in keratoconus. Materials and methods A retrospective nonrandomized review of 8 eyes of 6 patients who underwent the Athens Protocol for progressive keratoconus. Each patient underwent topography-guided ablation followed by CXL procedure. Follow-up Follow-up was done on day 1, day 7, and then at 1, 3, 6, and 12 months. Results There was a rapid and significant improvement in uncorrected visual acuity and best-corrected visual acuity in 100% eyes, a reduction of keratometric values, and symmetry between vertical hemimeridians. Topographic evaluation showed a marked improvement in irregularity. There were no signs of keratoconic progression noted in any of the eyes on last follow-up. No adverse events were reported in any patient. Conclusion Simultaneous surface ablation + CXL seems to be a promising treatment capable of offering patients functional vision and halting progression of the disorder. Precis Simultaneous topography-guided custom ablation treatment and photorefractive keratectomy with CXL offers keratoconic patients intolerant to contact lenses both stabilization of the cornea and improved functional vision with spectacles correction. How to cite this article Karmona L, Sela T, Franco O, Shoshani A, Munzer G, Kaiserman I. Simultaneous Topography-guided Surface Ablation with Collagen Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2016;5(2):71-76.
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Sakhnov, S. N., O. A. Klokova, A. V. Piskunov, R. O. Damashauskas, M. S. Geidenrich, and E. I. Dyakonova. "New avenues of preoperative evaluation before corneal refractive surgery during the COVID-19 pandemic." Russian Journal of Clinical Ophthalmology 21, no. 2 (2021): 72–77. http://dx.doi.org/10.32364/2311-7729-2021-21-2-72-77.
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Aim: to assess the reproducibility and comparability of measurements produced by Visionix VX130+ and their consistency with data produced by Topcon KR-800, NT-530P, Oculyzer, and RTVue-100. Patients and Methods: 124 patients (248 eyes) aged 18–45 years (mean age 25.24±7.5 years) were enrolled. Refractometry, IOP levels, and pachymetry measured by Visionix VX130+ system (LLC “Visionix Rus” — affiliated company of Luneau Technology Operations) were compared to the readings produced by Topcon KR-800 Auto Kerato-Refractometer (Topcon, Japan), Nidek NT-530P non-contact tonometer (Nidek, Japan), CT200 Goldman applanation tonometer (Reichert, USA), ALLEGRO Oculyzer (WaveLight AG, Germany), and RTVue-100 (Optovue, USA). Results: refractometry produced by Visionix VX130+ is highly reproducible and stable. Mean spread of spherical equivalent was 0.22±0.22 D and mean spread of cylindrical equivalent was 0.23±0.16 D. No significant differences were revealed between refractometry readings produced by Visionix VX130+ and Topcon KR-800 in patients with myopia (p>0.05). Both Visionix VX130+ and Nidek NT-530P (automated IOP measurements) produce two values, i.e., with and without corneal thickness. Our findings suggest that mean values are virtually similar in Visionix VX130+ group (p>0.05) while Nidek NT-530P produces significant differences (p<0.05). Mean central corneal thickness (CCT) measured by Visionix VX130+ was almost similar to CCT measured by Oculyzer (the difference was 3.8±2.23 μm, р>0.05) and greater than CCT measured by RTVue-100 (р<0.05). Conclusion: clinical trials comparing the readings produced by Visionix VX 130+ and other devices whose reliability was evidenced by long-term clinical experience have demonstrated that Visionix VX 130+ multifunctional diagnostic system is fully in line with the COVID-19 pandemic requirements. This device provides the measurements for performing safe and effective corneal refractive surgery for refractive errors. Keywords: corneal refractive procedure, pneumotonometry, aberrometry, corneal topography, pachymetry, cornea, intraocular pressure. For citation: Sakhnov S.N., Klokova O.A., Piskunov A.V. et al. New avenues of preoperative evaluation before corneal refractive surgery during the COVID-19 pandemic. Russian Journal of Clinical Ophthalmology. 2021;21(2):72–77. DOI: 10.32364/2311-7729-2021-21-2-72-77.
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Barbara, Ramez, and Adel Barbara. "How to improve Visual Acuity after Intrastromal Corneal Ring Segments? Implantation for Keratoconus and Post-LASIK Ectasia." International Journal of Keratoconus and Ectatic Corneal Diseases 3, no. 2 (2014): 69–75. http://dx.doi.org/10.5005/jp-journals-10025-1082.
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ABSTRACT Keratoconus (KC) is an ecstatic corneal disease that causes irregular astigmatism which cannot be corrected by glasses, the irregular astigmatism causes loss of visual acuity (VA) both the uncorrected and the corrected VA, in addition to deterioration in the quality of vision. Contact lenses (CLs) improve the VA but cannot be tolerated in many cases due to several causes, such as loss of motivation, atopic and allergic conjunctivitis that are more frequently associated with KC and dry eyes. Intrastromal corneal ring segments implanted in keratoconic eyes improve uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), reduce myopia, astigmatism, high order aberrations (HOA) and regularizes the cornea (less irregular astigmatism), similar results are achieved in the treatment of post-LASIK and post PRK ectasia. These results were confirmed in long-term follow-up. The more advanced the KC the more is the effect of the ICRS but the less the functional VA achieved and vice versa. Thicker rings are more effective, and the smaller the optical zone the more is the effect of the ICRS. The aim of ICRS implantation in KC is not to be free of glasses or CL but to enable the patient of seeing with glasses or to tolerate CL in order to prevent or delay the need for penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK). In many cases, we can achieve a functional and satisfactory UCVA with no need for glasses and this is the case in nonadvanced KC but not in the advanced cases. In some cases, the results achieved need additional means to improve VA in order to get satisfactory VA. There are nonsurgical and surgical means to improve VA after ICRS, these means will be reviewed in this article. How to cite this article Barbara A, Barbara R. How to improve Visual Acuity after Intrastromal Corneal Ring Segments? Implantation for Keratoconus and Post-LASIK Ectasia. Int J Kerat Ect Cor Dis 2014;3(2):69-75.
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Mohamed, R. F., R. M. F. Elghazawy, S. M. Fawzy, and T. A. Badran. "Assessment of Epithelial Thickness in Keratoconic Patients Before and After Intracorneal Ring Segment Implantation Using Anterior Segment Optical Coherence Tomography." QJM: An International Journal of Medicine 113, Supplement_1 (2020). http://dx.doi.org/10.1093/qjmed/hcaa058.004.
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Abstract Background Keratoconus, the most common primary corneal ectasia, is a bilateral asymmetric corneal degeneration accompanied with local corneal thinning and occurs mostly in the inferior and central part of the cornea, it usually causes high myopia and irregular astigmatism which results in poor quality of vision. Based on disease severity, many treatment modalities exist including glasses and contact lenses for mild to moderate disease, while corneal graft preserved for more advanced disease. In advent of alternative treatments, intrastromal ring implantation have been introduced which improves visual acuity and optical aberrations and also corrects refractive errors and mean keratometric data, anterior segment Optical cohehernce Tomography epithelial mapping is anew modality to assess epithelial thickness. Objective: To investigate epithelial thickness changes in keratoconic patients before and after intracorneal ring segment implantation using AS OCT. Methods: Thirty eyes with early to moderate keratoconus were included in this prospective interventional case series study which has been conducted at patients from Ain shams university hospitals, after the approval of the research ethical committee in the Faculty of Medicine, Ain Shams University between March to October. All cases underwent a Complete ophthalmological examination before surgery. the examination included Visual acuity assessment and Best corrected visual acuity. Slit Lamp Biomicroscopy examination with fundus examination through dilated pupil using D lens & Corneal Topography, Anterior segment Optical cohehernce Tomography Epithelial mapping(zeiss). Results: we found that epithelial thickness showing statistically significant change comparing pre and post operative epithelial mapping especially in certain areas in the map,area ( _ ),( _ ) mm. Conclusion: There is increase in epithelium thickness in keratoconic corneas after intracorneal ring segment implantation to compensate for stromal irregularities in patients with keratoconus.
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Jiang, Fan, Xiaopeng Huang, Houxue Xia, et al. "The Spatial Distribution of Relative Corneal Refractive Power Shift and Axial Growth in Myopic Children: Orthokeratology Versus Multifocal Contact Lens." Frontiers in Neuroscience 15 (June 9, 2021). http://dx.doi.org/10.3389/fnins.2021.686932.
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PurposeTo determine if the spatial distribution of the relative corneal refractive power shift (RCRPS) explains the retardation of axial length (AL) elongation after treatment by either orthokeratology (OK) or multifocal soft contact lenses (MFCLs).MethodsChildren (8–14 years) were enrolled in the OK (n = 35) or MFCL (n = 36) groups. RCRPS maps were derived by computing the difference between baseline and 12-month corneal topography maps and then subtracting the apex values. Values at the same radius were averaged to obtain the RCRPS profile, from which four parameters were extracted: (1) Half_x and (2) Half_y, i.e., the x- and y-coordinates where each profile first reached the half peak; (3) Sum4 and (4) Sum7, i.e., the summation of powers within a corneal area of 4- and 7-mm diameters. Correlations between AL elongation and these parameters were analyzed by multiple linear regression.ResultsAL elongation in the OK group was significantly smaller than that in the MFCL group (p = 0.040). Half_x and Half_y were also smaller in the OK group than the MFCL group (p &lt; 0.001 each). Half_x was correlated with AL elongation in the OK group (p = 0.005), but not in the MFCL group (p = 0.600). In an analysis that combined eyes of both groups, Half_x was correlated with AL elongation (β = 0.161, p &lt; 0.001).ConclusionsThe OK-induced AL elongation and associated RCRPS Half_x were smaller than for the MFCL. Contact lenses that induce RCRPS closer to the corneal center may exert better myopia control.
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Raqqad, Nancy Al, Naser Al Fgara, and Mohammad Dros. "Toric and Phakic IOLs for the Treatment of Astigmatism and/or High Myopia: Our Experience at Prince Hashem Hospital Zarqa." Journal of Advances in Medicine and Medical Research, March 9, 2019, 1–6. http://dx.doi.org/10.9734/jammr/2018/v28i1230045.
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Aim: to share our experience in treating patients with high myopia and or astigmatism using toric and phakic intraocular lenses at Prince Hashem Hospital in Jordan.
 Patients and Methods: This is a retrospective study of fifty eyes of 36 patients who were treated between June 2015 and July 2016 at Prince Hashem Hospital in Jordan. Patients’ age ranged between 22 years and 54 years. All patients had high myopia (≥6 dipoters) and/or astigmatism and were not eligible for surface laser ablation and intolerant to contact lenses. Preoperative best corrected visual acuity BCVA, ophthalmological slit lamp examination, manifest and cycloplegic refraction, corneal topography using Oculus Pentacam and IOL master were obtained in all patients.
 Results: In all the patients preoperative refraction ranged between -4 to -33 sphere and -3.5 to -8 cylinder. Phacoemulsification and implantation of toric intraocular lenses (IOL) was done in 21 patients, Visian implantable collamer lens (sphere and toric ICL) were implanted in 18 patients and toric iris claw lenses (Ophthec Artisan/ Artiflex) were used for the remaining 11 patients. All surgical procedures were done under local anesthesia. All patients showed improvement in their visual acuity after surgery and spectacle independence.
 Complications were minimal in the form of lens rotation resulting in decrease in BCVA seen in 3 patients with toric IOLs and two Visian ICLs patients. High intraocular pressure was seen in one patient.
 Mean follow-up period was between 6 months to 1 year.
 Conclusion: Toric and phakic IOLs can be very useful in correcting astigmatism and or myopia. Proper patient selection and counseling is essential to ensure best refractive outcome and avoid complications.
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Pateras, E., and A. Nousi. "The Reliability between Placido Topography and Scheimpflug Topography in Normal Corneas with Astigmatism less Than 0.50 Dc." Ophthalmology Research: An International Journal, April 3, 2020, 27–35. http://dx.doi.org/10.9734/or/2020/v12i130140.
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Purpose: This Clinical research was targeted to experimentally investigate the reliability between Placido topography and Scheimpflug topography in normal corneas with astigmatism ≤ ±0.50 Dc by comparing the refractive powers at the 4 main meridians (180⁰ - 90⁰) in order to study any differences between the two topographers and their reliability. Comparing the reliability measurements of Placido disk topography (CSO- Modi 02 Corneal Topographer with Phoenix Full & Pupil Module Software) with those of a high-resolution rotating Scheimpflug camera (Pentacam-Oculus,) and assess the agreement between these two topographers in measuring corneal power in normal eyes without astigmatism (≤ 0.50 Dc).
 Methods and Materials: Measurements were taken from 56 eyes corresponding to a proportion of patients, of which 26 were men with a mean age of ± 30 years and 30 were women with a mean age of ± 27 years. Refractive power maps were taken from the anterior cornea, having results for the steep meridian value (Ks), the flat meridian value (Kf), mean keratometric value (Km), and cornea astigmatism (Ks-Kf). The same examiner took all the data from measuring these 56 eyes. The results for each refractive map from the two topographers was taken with values for meridians (180⁰- 90⁰). Then the there was a statistical analysis comparing the values of (CSO) and (Pentacam) for those 56 eyes measured.
 Results: The statistical analysis for all meridians based on the results and as far as normal corneas with astigmatism ≤ ±0.50 Dc are concerned, the Placido topography (CSO) and Scheimpflug imaging technique (Pentacam), can be considered as equivalent in terms of diagnostic credibility and accuracy for primary health care, fitting contact lenses, etc. as the correlation coefficient r did not show any important differences for both instruments. For the 90⁰ meridian the correlation coefficient was 0.79, Significance level P=0.0001 and 95% confidence interval ranges from 0.67 to 0.87. For the 180⁰ meridian the correlation coefficient was 0.48, Significance level P<0.0001 and 95% confidence interval ranges from 0.25 to 0.66.
 Conclusion: In terms of diagnosis of pathology and follow-up, contact lens fitting especially for the anterior cornea surface these two instruments can work quite the same that’s why a small clinical practitioner should have at least a Placido topographer. Corneal topography is an important instrument in order to measure the shape and refractive power of the cornea. Corneal topography gives practitioners an important tool to fit contact lenses asses the power and the cornea shape and helps to evaluate complications of the contact lens in relation with the corneal surface. These instruments continue to develop techniques and software in order to investigate and evaluate corneal surfaces and the integrity of the tear film, so that they can provide better solutions for their contact lens patients.
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Kang, Pauline, Vinod Maseedupally, Paul Gifford, and Helen Swarbrick. "Predicting corneal refractive power changes after orthokeratology." Scientific Reports 11, no. 1 (2021). http://dx.doi.org/10.1038/s41598-021-96213-x.
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AbstractThis study aimed to characterise corneal refractive power (CRP) changes along the principal corneal meridians during orthokeratology (OK). Nineteen myopes (mean age 28 ± 7 years) were fitted with OK lenses in both eyes. Corneal topography was captured before and after 14 nights of OK lens wear. CRP was calculated for the central 8 mm cornea along the horizontal and vertical meridians. The central-paracentral (CPC) power ratio was calculated as the ratio between maximum central and paracentral CRP change from individual data. There was a significant reduction in CRP at all locations in the central 4 mm of the cornea (all p < 0.001) except at 2 mm on the superior cornea (p = 0.071). A significant increase in CRP was evident in the paracentral zone at 2.5, 3 and 3.5 mm on the nasal and superior cornea and at 3.5 and 4 mm on the temporal cornea (all p < 0.05). No significant change in CRP was measured in the inferior cornea except decreased CRP at 2.5 mm (p < 0.001). CPC power ratio in the nasal and temporal paracentral regions was 2.49 and 2.23, respectively, and 2.09 for both the inferior and superior paracentral corneal regions. Our results demonstrates that OK induced significant changes in CRP along the horizontal and vertical corneal meridians. If peripheral defocus changes are inferred from corneal topography, this study suggests that the amount of myopia experienced on the peripheral retina was greater than twice the amount of central corneal power reduction achieved after OK. However, this relationship may be dependent on lens design and vary with pupil size. CPC power ratios may provide an alternative method to estimate peripheral defocus experienced after OK.
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Zhong, Xingwu, Richard Wu, Gang Tan, et al. "The efficacy of the Hiline gas permeable contact lens for the management of Keratoconus." Canadian Journal of Optometry 69, no. 2 (2007). http://dx.doi.org/10.15353/cjo.69.716.
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Purpose: To investigate the efficacy of the Hiline® gas permeable contact lens (Hiline® GP) for keratoconus in clinical practice in correcting visual acuity.
 Methods: 218 eyes of 126 patients with keratoconus were fitted with Hiline® lenses. The fit of the lenses was evaluated. Visual acuity measurements were taken with spectacle lenses and with the Hiline lenses. The period of follow-up to observe for complications ranged from 3 to 27 months.
 Results: In all eyes, the Hiline® GP provided acceptable vision. There was a statistically significant improvement in vision with the Hiline® GP compared with spectacle lenses (t=10.90, p<0.0001). Initial evaluation showed that 169 lenses (77.52%) demonstrated a three-pointtouch relationship with the cornea 38 lenses (17.43%) had an apical clearance relationship with the cornea and 11 lenses (5.05%) had an apical bearing relationship. No severe complications were observed.
 Conclusions: Using corneal topography as a guide, a high success rate was achieved with the Hiline® GP design. It is easy to reach the ideal fit and to improve the visual acuity. These indicate the usefulness of Hiline® lens in clinical practice.
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Singh, Kirti, Mainak Bhattacharyya, Abhishek Goel, Ritu Arora, Nikhil Gotmare, and Himshikha Aggarwal. "Orthokeratology in Moderate Myopia: A Study of Predictability and Safety." Journal of Ophthalmic and Vision Research, April 6, 2020. http://dx.doi.org/10.18502/jovr.v15i2.6739.
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Purpose: Literature is relatively silent on safety profile and predictability of orthokeratology lenses in terms of myopia correction and prevention of further progression, especially in semi-tropical countries; this study was designed to fill this gap.
 Methods: This prospective, intervention case series enrolled 30 eyes of 30 patients with myopia up to –5.5 diopters (D). Patients were randomized into two groups of 15 each; the study group was prescribed overnight orthokeratology (OK) lenses, while the control group used daily wear conventional soft contact lenses. Follow-up examinations were performed after 1 h and 6 h, and then at 1, 7, 15, 30 days, and 4 months post lens wear. Uncorrected visual acuity (UCVA), contrast sensitivity, keratometry, central corneal thickness (CCT), and tear film break up time (TBUT) were evaluated at each follow-up examination.
 Results: All patients attained a visual acuity of 0.00 Logarithm of the Minimum Angle of Resolution (logMAR) after one week of lens use, which was maintained throughout the study period. While patients allotted to the study group had a gain of 8.1 Snellen lines (UCVA), those in the control group gained 8.9 lines (BCVA) at the end of follow-up period. In the OK group, cornea showed a flattening of 0.8 D (mean keratometry) after single overnight usage of OK lens and overall flattening of 1.2 D compared to baseline, at the end of four months. The change in contrast sensitivity, corneal endothelial specular count, axial length and tear film status was not significant in either group.
 Conclusion: Orthokeratology is an effective and safe modality to correct moderate myopia in motivated young adults. No side effects were encountered after a short-term follow-up in participants who resided in semi-tropical environments.
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Lopes-Ferreira, Daniela, Alicia Ruiz-Pomeda, Belén Peréz-Sanchéz, António Queirós, and César Villa-Collar. "Ocular and corneal aberrations changes in controlled randomized clinical trial MiSight® Assessment Study Spain (MASS)." BMC Ophthalmology 21, no. 1 (2021). http://dx.doi.org/10.1186/s12886-021-01865-y.
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Abstract Background To compare ocular and corneal inherent aberrations in the naked eyes of randomly selected children fitted with MiSight contact lenses (CL) for myopia control, versus children corrected with single-vision spectacles (control), over a 24-months period. Methods Children aged 8 to 12 years, with myopia (-0.75 to -4.00 D sphere) and astigmatism (< -1.00 D cylinder) were randomly assigned to the lens study group (MiSight) or the control group (single-vision spectacles). The root mean square aberration (RMS) was determined as corneal (RMS_C), corneal high order RMS (HO_RMS_C), corneal low order RMS (LO_RMS_C), ocular (total) RMS (RMS_T), ocular high order RMS (HO_RMS_T), ocular low order RMS (LO_RMS_T), corneal spherical aberration (SA_C) and ocular SA (SA_T) were calculated by aberrometry measures at the baseline, on 12-months and 24-months visits. A 5 mm diameter was defined for the analysis in all visits for all subjects. Only the dominant eye was analyzed. Results Seventy-four subjects completed the clinical trial: 41 subjects from the MiSight group (age: 11.01 ± 1.23 years) and 33 from the single-vision group (age: 10.12 ± 1.38 years). RMS_T significantly changed (0.57 ± 0.20 µm, p = 0.029) after 24-months in the control group. In the MiSight group no significant changes were registered (p > 0.05). The SA_C and SA_T did not reveal significant changes between visits or between groups (p > 0.05). Conclusions Along 2 years, MiSight CL did not induce significant changes in RMS of anterior cornea or total ocular RMS. Contrary, in control group the RMS_T significantly changed as response of greater eye growth and myopia progression. The results obtained in present study allow to predict corneal or total aberration changes, in children, in response of wearing of MiSight lens along the time. Trial registration : ClinicalTrials.gov Identifier: NCT01917110.