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Background: To report the refractive outcomes of StreamLight transepithelial photorefractive keratectomy (PRK). Methods: A retrospective case series was conducted which included a total of 205 eyes of 109 patients who underwent StreamLight transepithelial PRK using the Alcon Wavelight EX500 excimer laser. All eyes had myopia or myopic astigmatism, and the preoperative spherical equivalent (SEQ) ranged from −0.63D to −7.25D. The primary postoperative outcomes were UDVA, CDVA and subjective refraction measured at least 3 months postoperatively. Results: Postoperatively, 196 eyes (95.6%) had a UDVA of 20/20 or better. The mean SEQ was −0.05 ± 0.31D and 189 eyes (92.2%) were within ±0.50D of the target SEQ. The mean refractive astigmatism was −0.28 ± 0.27D, and 181 eyes (88.3%) had ≤ 0.50D of astigmatism. The mean safety and efficacy indices were 1.01 ± 0.08 and 0.97 ± 0.12, respectively. Eight eyes lost 1 line of CDVA. Six of these were noted to have significant dry eyes and 2 had corneal haze. No eye lost two or more lines of CDVA. Conclusions: StreamLight transepithelial PRK results in excellent refractive outcomes for myopia and myopic astigmatism. [ABSTRACT FROM AUTHOR]

Shohei Nishida,1 Yasuya Inomata,1 Akira Hirata2 1Inomata Eye Clinic, Kumamoto City, Kumamoto, Japan; 2Hayashi Eye Hospital, Fukuoka City, Fukuoka, JapanCorrespondence: Shohei Nishida; Yasuya Inomata, Email shohei.n.0126@outlook.jp; inoyas@kxb.biglobe.ne.jpPurpose: We examined differences in the accuracy of three intraocular lens (IOL) calculation formulas: the traditional Sanders-Retzlaff-Kraff/Theoretical (SRK/T) formula; the Barrett Universal II (BU II) formula, which is a new-generation IOL calculation formula; and the postoperative spherical equivalent prediction using artificial intelligence and linear algorithms developed by Debellemanière, Gatinel, and Saad formula (PEARL-DGS [PEARL]) formula, and evaluated factors that cause postoperative refractive error (PE).Patients and Methods: The study included 205 patients (205 eyes) with a mean age of 75.2 ± 8.7 years who underwent cataract surgery at our institution from December 2018 to October 2023. The PE of the three IOL calculation formulas was calculated and compared. Multivariate logistic regression analysis was performed with a PE higher than ± 0.50 D as the dependent variable, and age, sex, axial length (AL), mean keratometry (mean K), anterior chamber depth (ACD), lens thickness (LT), and white-to-white (WTW) as independent variables.Results: The mean PE (ME) ± standard deviation of the SRK/T, BU II, and PEARL formulas was 0.11 ± 0.52, 0.11 ± 0.50, and 0.21 ± 0.50 D, respectively. MEs of the three IOL calculation formulas were significantly different from 0 (p < 0.01). The median absolute error (MedAE) was not significantly different among the three IOL calculation formulas (p = 0.83). The percentage of PE within ± 0.50 D was not significantly different among the three IOL calculation formulas (p = 0.13). Multivariate logistic regression analysis showed that the significantly associated factors with PE higher than ± 0.50 D were AL, ACD, and LT for the SRK/T formula, sex and LT for the BU II formula, and LT for the PEARL formula (all p < 0.05).Conclusion: In the BU II and PEARL formulas, AL was excluded as a factor affecting PE, indicating that LT was a risk factor.Keywords: cataract, lens thickness, logistic models, refractive surgical procedures

Introduction: Laser Subepithelial Keratomileusis (LASEK) is a type of surface ablation laser surgery that offers a solution to patients for correcting their ametropia. In rare instances, LASEK has been associated with complications such as the development of postoperative haze, infection, and poor visual outcomes. Imaging features detected within the patient’s cornea using In-Vivo Confocal Microscopy (IVCM) have aided in identifying the cellular basis of complications like these. Aim: To observe and describe the morphological changes seen on IVCM in patients following LASEK surgery. Materials and Methods: This observational study aimed to assess the quantity and morphology of anterior and posterior keratocytes in adults aged 18 years and older. Five participants (9 eyes) who presented for follow-up appointments following LASEK surgery at Manchester Royal Eye Hospital (MREH), United Kingdom, from July to December 2018 were recruited for the study. The cell counts of the anterior and posterior keratocytes were calculated using the Heidelberg Eye Explorer software. The images were analysed with the Image J program (National Institutes of Health, Bethesda, USA). Nerve fibers were assessed using the ACCMetrics program (University of Manchester, UK). The t-test was used to establish the statistical association between variables. Results: Morphological changes, such as zones of hyperreflectivity beneath the epithelium, were observed in all the recruited participants. Immune cells and sub-basal nerve abnormalities were detected in several participants. The number of keratocytes in the anterior stroma of all the participants was found to be much lower compared to that of the control. Only participant number 3 had a greater number of keratocytes in the anterior stromal layer (454 and 514 cells/mm2) compared to the other participants, who had a cell count ranging between 156 to 262 cells/mm2. Conclusion: It is evident that visible changes are noted both quantitatively and morphologically in both the anterior and posterior keratocytes postoperatively. More research is required with larger controlled studies to investigate the IVCM imaging biomarkers and morphological features that represent the wound healing process and the factors influencing visual outcomes, ensuring that postoperative complications can be minimised.

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Laser Subepithelial Keratomileusis (LASEK) is a type of surface ablation laser surgery that offers a solution to patients for correcting their ametropia. In rare instances, LASEK has been associated with complications such as the development of postoperative haze, infection, and poor visual outcomes. Imaging features detected within the patient's cornea using In-Vivo Confocal Microscopy (IVCM) have aided in identifying the cellular basis of complications like these. Aim: To observe and describe the morphological changes seen on IVCM in patients following LASEK surgery. Materials and Methods: This observational study aimed to assess the quantity and morphology of anterior and posterior keratocytes in adults aged 18 years and older. Five participants (9 eyes) who presented for follow-up appointments following LASEK surgery at Manchester Royal Eye Hospital (MREH), United Kingdom, from July to December 2018 were recruited for the study. The cell counts of the anterior and posterior keratocytes were calculated using the Heidelberg Eye Explorer software. The images were analysed with the Image J program (National Institutes of Health, Bethesda, USA). Nerve fibers were assessed using the ACCMetrics program (University of Manchester, UK). The t-test was used to establish the statistical association between variables. Results: Morphological changes, such as zones of hyperreflectivity beneath the epithelium, were observed in all the recruited participants. Immune cells and sub-basal nerve abnormalities were detected in several participants. The number of keratocytes in the anterior stroma of all the participants was found to be much lower compared to that of the control. Only participant number 3 had a greater number of keratocytes in the anterior stromal layer (454 and 514 cells/mm2) compared to the other participants, who had a cell count ranging between 156 to 262 cells/mm2. Conclusion: It is evident that visible changes are noted both quantitatively and morphologically in both the anterior and posterior keratocytes postoperatively. More research is required with larger controlled studies to investigate the IVCM imaging biomarkers and morphological features that represent the wound healing process and the factors influencing visual outcomes, ensuring that postoperative complications can be minimised. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective: To study vertex-optical distance variation and estimate its impact on manifest refraction. Methods: Prospective study in a private clinic using the Vision-S™ 700 with five forehead positions. Forehead on the third position showed the closest vertex-optical distance of 12mm. Results: Analysis of 52 eyes from 26 patients revealed mean differences in vertex-optical distance of 12.25mm (right eye) and 11.75mm (left eye). A 2mm change in vertex-optical distance resulted in a 0.05D change for a 5D spherical equivalent and 0.20D for a 10D equivalent. Conclusion: Vertex-optical distance varies among patients and is influenced by forehead adjustment. These variations impact refraction accuracy and treatment evaluation. Adjusting the forehead to the third position on the Vision-S™ 700 is recommended.

Objective: Recent studies imply extensive applications for the human amniotic membrane (hAM) and its extract inmedicine and ophthalmology. The content of hAM meets many requirements in eye surgeries, such as refractivesurgery as the most important and commonly used method for treating the dramatically increasing refractive errors.However, they are associated with complications such as corneal haziness and corneal ulcer. This study was designedto evaluate the impact of amniotic membrane extracted eye drop (AMEED) on Trans-PRK surgery complications.Materials and Methods: This interventional and historical study was performed during two years (July 1, 2019-September1, 2020). Thirty-two patients (64 eyes), including 17 females and 15 males, aged 20 to 50 years (mean age of 29.59 ±6.51) with spherical equivalent between -5 to -1.5 underwent Trans Epithelial Photorefractive Keratectomy (Trans-PRK)surgery. One eye was selected per case (case group) and the other eye was considered as control. Randomizationwas done using the random allocation rule. The case group was treated with AMEED, and the artificial tear drop every4 hours. The control eyes received artificial tear drops instilled every 4 hours. The evaluation continued for three daysafter the Trans-PRK surgery.Results: A significant decrease in CED size was found in the AMEED group on the second day after surgery (P=0.046).Also, this group had a substantial reduction in pain, hyperemia, and haziness.Conclusion: This study showed that AMEED drop can increase the healing rate of corneal epithelial lesions after Trans-PRK surgery and reduce the early and late complications of Trans-PRK surgery. Researchers and Ophthalmologistsshould consider AMEED as a selection in patients with persistent corneal epithelial defects and patients who havedifficulty in corneal epithelial healing. We understood AMEED has a different effect on the cornea after surgery;therefore, the researcher must know AMEED’s exact ingredients and help expand AMEED uses.

ABSTRACT LASIK is a refractive surgical procedure in which a corneal flap is created to expose the corneal stromal bed. Preoperative estimation of corneal flap thickness is necessary to calculate the percentage tissue altered in LASIK, an important quantitative risk factor for ectasia. The objective of this study was to assess flap thickness and calculate percentage tissue altered to check if unexpectedly thicker flaps and higher percentage tissue altered could pose as risk factors of ectasia. Four subjects (eight eyes) were submitted to mechanical LASIK in 2009 and 2010. Pre and postoperative clinical and tomographic data were reviewed. Mean preoperative estimated percentage tissue altered was 39.18±1.31%, which was borderline for increased ectasia risk when considering the limit of 40%. However, when considering the postoperatively measured flap thickness, the actual mean percentage tissue altered turned out to be 45.17 ± 4.13%, which was significantly higher than predicted preoperatively (p=0.002). Unexpectedly higher postoperative percentage tissue altered may be responsible for corneal ectasia after mechanical LASIK.

Objective: Unusual setting of medical care. Background: Refractive surgery is one of the most frequently performed ocular surgeries worldwide. Implantation of the posterior chamber phakic intraocular lens has advantages over laser vision correction, especially in high refractive error cases. We present a case of a young adult women with poor vision who underwent bilateral posterior chamber phakic intraocular lens explantation due to high vault, shallow anterior chambers, and a picture of cone-rod dystrophy. Case Report: A 23-year-old woman was referred for poor vision following an implantation of bilateral toric implantable collamer lens (ICL) implantation when she was 18 years old for high myopic astigmatism and anisometropia. On presentation, the best corrected visual acuity was 4-6/200 and 2-3/200 in the right eye and left eye, respectively. Slit lamp examination indicated a clear cornea with pigment deposition on the endothelium, high ICL vault, shallow anterior chamber, and bowing of the iris bilaterally. The patient underwent bilateral removal of the ICLs on separate visits, yet the vision remained unchanged. Diagnostics revealed that the patient had bull's eye maculopathy with atrophy due to her cone-rod dystrophy, which caused the poor vision. Conclusions: This report emphasizes the need for careful and appropriate patient and intraocular size selection for refractive surgery. It indicates the importance of thorough medical examination, including genetic testing, fundus examination, and optical coherence tomography when retinal dystrophy is suspected. Generally, close followup is crucial in the setting of high vaulting following ICL implantation to prevent secondary complications. [ABSTRACT FROM AUTHOR]

Objective: Recent studies imply extensive applications for the human amniotic membrane (hAM) and its extract in medicine and ophthalmology. The content of hAM meets many requirements in eye surgeries, such as refractive surgery as the most important and commonly used method for treating the dramatically increasing refractive errors. However, they are associated with complications such as corneal haziness and corneal ulcer. This study was designed to evaluate the impact of amniotic membrane extracted eye drop (AMEED) on Trans-PRK surgery complications. Materials and Methods: This randomized controlled trial was performed during two years (July 1, 2019-September 1, 2020). Thirty-two patients (64 eyes), including 17 females and 15 males, aged 20 to 50 years (mean age of 29.59 ± 6.51) with spherical equivalent between -5 to -1.5 underwent Trans Epithelial Photorefractive Keratectomy (Trans-PRK) surgery. One eye was selected per case (case group) and the other eye was considered as control. Randomization was done using the random allocation rule. The case group was treated with AMEED, and the artificial tear drop every 4 hours. The control eyes received artificial tear drops instilled every 4 hours. The evaluation continued for three days after the Trans-PRK surgery. Results: A significant decrease in CED size was found in the AMEED group on the second day after surgery (P=0.046). Also, this group had a substantial reduction in pain, hyperemia, and haziness. Conclusion: This study showed that AMEED drop can increase the healing rate of corneal epithelial lesions after TransPRK surgery and reduce the early and late complications of Trans-PRK surgery. Researchers and Ophthalmologists should consider AMEED as a selection in patients with persistent corneal epithelial defects and patients who have difficulty in corneal epithelial healing. We understood AMEED has a different effect on the cornea after surgery; therefore, the researcher must know AMEED’s exact ingredients and help expand AMEED uses (registration number: TCTR20230306001). [ABSTRACT FROM AUTHOR]

PURPOSE: To describe the clinical and intraoperative findings of an anatomic abnormality in children that resembles sagging eye syndrome documented in older adults and that led to recurrent esotropia after surgery. METHODS: We reviewed records of 4 patients with substantial recurrent esotropia after bilateral medial rectus recession who required subsequent surgery combining lateral rectus resection with correction of the anatomic abnormality affecting the lateral rectus path. Binocular alignment was sequentially analyzed. RESULTS: Three young patients (2-3 years of age) presented with acquired esotropia but minimal cycloplegic refractive error. The fourth patient (14 years of age) initially had moderate hyperopia and partially accommodative esotropia, but subsequently developed marked bilateral overelevation in adduction. In all patients, esotropia recurred within 5Δ of preoperative deviation after bilateral medial rectus recession. Surgical exposure demonstrated that bilateral lateral rectus paths were inferiorly displaced more than one-half tendon width from their normal paths near the globes equator, despite normal scleral insertions. Equatorial myopexy and lateral rectus resection resulted in stable esotropia correction. CONCLUSIONS: Lateral rectus sag in children creates a type of acquired esotropia and overelevation in adduction poorly responsive to standard surgery but correctable with lateral rectus resection and equatorial myopexy that normalizes the lateral rectus path through permanent scleral fixation.

Objective: The purpose of this study was to develop and apply an online questionnaire to assess knowledge in Refractive Surgery in the analyzed population. Methods: An online questionnaire was applied to a population composed of 840 volunteer participants over 18 years of age. Results: The mean age of population was 37.85 years, of whom 60.1% were female. 20.95% of the participants reported having undergone previous eye surgery, 73.86% of which had a refractive objective. Among these, 73.08% were satisfied / very satisfied with the result. The most important criterion when choosing a refractive surgeon was the indication by a friend who underwent the procedure (43.81%). It is noteworthy that the participants who underwent refractive surgery disagreed more than the other people that “the surgery is a simple and risk-free procedure” (p = 0.0045) and that “the main objective of the surgery is to “zero” the diopter” (p = 0.0252). Conclusion: It is essential to improve population’s preoperative knowledge about Refractive Surgery, as well as continuing education for ophthalmologists. Therefore, this study encourages the development of new education tools with clear and easily accessible information, which should be informative, and not convincing. [ABSTRACT FROM AUTHOR]

LASIK is a refractive surgical procedure in which a corneal flap is created to expose the corneal stromal bed. Preoperative estimation of corneal flap thickness is necessary to calculate the percentage tissue altered in LASIK, an important quantitative risk factor for ectasia. The objective of this study was to assess flap thickness and calculate percentage tissue altered to check if unexpectedly thicker flaps and higher percentage tissue altered could pose as risk factors of ectasia. Four subjects (eight eyes) were submitted to mechanical LASIK in 2009 and 2010. Pre and postoperative clinical and tomographic data were reviewed. Mean preoperative estimated percentage tissue altered was 39.18±1.31%, which was borderline for increased ectasia risk when considering the limit of 40%. However, when considering the postoperatively measured flap thickness, the actual mean percentage tissue altered turned out to be 45.17 ± 4.13%, which was significantly higher than predicted preoperatively (p=0.002). Unexpectedly higher postoperative percentage tissue altered may be responsible for corneal ectasia after mechanical LASIK. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Accurate refraction is arguably the most important parameter for a successful laser vision correction surgery and is based on a combination of manifest and cycloplegic refraction. Wavefront-based objective refraction may be useful in the evaluation of patients. So far, the reliability of objective refraction as measured using the Pentacam® AXL Wave has not been published in the literature. Methods: This was a prospective study including a total of 168 eyes belonging to 84 young non-presbyopic patients evaluated for refractive surgery. Pentacam® AXL Wave full sequence was taken for all patients. Then, a clinician who was unaware of the objective refraction results performed a full physical examination, including manifest refraction starting from an autorefractometer value. All refraction values were transferred to astigmatic power vectors as per the Thibos method. Reliability of the different vectors and a unifying blur value were compared using Spearman correlation, Bland–Altman plot, and intraclass correlation coefficient. Results: The mean age was 28.8 ± 5.4 years, with a female preponderance (60.7%). The correlation between both eyes was high. The difference in M vector between subjective and objective refraction was 0.16 D, while the difference was 0.04 and 0.01 D for the J0 and J45 vectors, respectively. Paired samples Student t was non-significant for all comparisons. Spearman rho correlations were high (0.666–0.924, all P < 0.001). Intraclass correlation coefficients were also high (0.890–0.966). Bland–Altman plots did not demonstrate any systematic errors. Conclusion: Wavefront-based refractive refraction obtained using the Pentacam® AXL Wave is highly agreeable and correlated with measurements obtained by manifest subjective refraction.

This study comprehensively reviewed publicly available image datasets for the anterior segment, with a focus on cataract, refractive, and corneal surgeries. The goal was to assess characteristics of existing datasets and identify areas for improvement. PubMED and Google searches were performed using the search terms "refractive surgery," "anterior segment," "cornea," "corneal," "cataract" AND "database," with the related word of "imaging." Results of each of these searches were collated, identifying 26 publicly available anterior segment image datasets. Imaging modalities included optical coherence tomography, photography, and confocal microscopy. Most datasets were small, 80% originated in the U.S., China, or Europe. Over 50% of images were from normal eyes. Disease states represented included keratoconus, corneal ulcers, and Fuchs dystrophy. Most of the datasets were incompletely described. To promote accessibility going forward to 2030, the ESCRS Digital Health Special Interest Group will annually update a list of available image datasets for anterior segment at www.escrs.org ., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS.)

Purpose: We aimed to evaluate the success of Chat Generative Pre-trained Transformer (ChatGPT), Bing, and Bard artificial intelligence programs, which were released free of charge by three different manufacturers, in correctly answering questions about lenses, cataract, and refractive surgery, and to investigate whether they are superior to each other., Methods: Seventy questions related to lens, cataract, and refractive surgery were obtained from the study questions section of the American Academy of Ophthalmology 2022 to 2023 Basic and Clinical Science Course Lens and Cataract and Refractive Surgery Books. The questions were asked separately for the ChatGPT, Bing, and Bard artificial intelligence programs. The answers were compared with answer keys and grouped as correct or incorrect. The accuracy rates of artificial intelligence programs were compared statistically., Results: ChatGPT, Bing, and Bard chatbots gave correct answers to 35 (50%), 43 (61.4%), and 50 (71.4%) questions asked, respectively. The rate of correct answers to the questions of the Bard artificial intelligence program was significantly higher than that of ChatGPT ( P = 0.009, Pearson's Chi-square test)., Conclusion: Although the currently released artificial intelligence chatbots can be used to access accurate information about lenses, cataracts, and refractive surgery, one should always be careful about the accuracy of the answers given., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Middle East African Journal of Ophthalmology.)

Purpose: To evaluate the intrasession repeatability of wavefront aberrations obtained by a combined adaptive optics visual simulator and Hartman-Shack aberrometer in pseudophakic eyes with and without previous corneal refractive surgery., Methods: Three consecutive measurements were performed in one eye of each individual. Total ocular aberrations were recorded up to the 5th Zernike order for a 4.5-mm pupil. Repeatability was assessed by calculating the within-subject standard deviation (S w ), the repeatability limit (R), and the intraclass correlation coefficient (ICC). Vector analysis was performed to assess astigmatism variability between scans., Results: The study enrolled 32 normal individuals and 24 individuals with a history of refractive surgery. In normal and eyes that had previous refractive surgery, respectively, the S w values were 0.155 and 0.176 diopters (D) for sphere and 0.184 and 0.265 D for cylinder. The S w values for all 3rd order terms ranged from 0.037 to 0.047 µm in normal eyes and 0.044 to 0.063 µm in eyes that had previous refractive surgery. The S w for primary spherical aberration was 0.020 µm in normal eyes and 0.026 µm in eyes that had previous refractive surgery. ICC values for measurements of astigmatism yielded larger variability (ICC = 0.751 and 0.879). However, both groups demonstrated excellent repeatability (ICC > 0.9) for root mean square higher order aberrations (RMS-HOA) and total RMS values., Conclusions: In pseudophakic eyes, the adaptive optics Hartmann-Shack device demonstrated acceptable repeatability for measurement of sphere and 3rd and 4th order HOAs with higher variability for astigmatism measurements, especially in eyes with a prior history of corneal refractive surgery. [ J Refract Surg . 2024;40(9):e645-e653.] .

Objective: Unusual or unexpected effect of treatment Background: Acute corneal hydrops refers to a rare complication of keratoconus and other ectatic disorders with potentially sight-threatening sequelae. Intrastromal corneal ring segment (ICRS) implantation is a surgical procedure performed as therapy for keratoconus when there is contact lens intolerance. ICRS migration along the tunnel made for its insertion is one of its most frequent complications. We believe this is the first published case of acute corneal hydrops and ICRS migration unfolding shortly after an uneventful ICRS implantation, and successfully managed with medical treatment and ICRS reimplantation, respectively. Case Report: A 17-year-old male, previously diagnosed with bilateral keratoconus 4 years earlier for which he underwent cross-linking surgery for both eyes 3 years prior, presented to our department for a first-time keratoconus assessment. His best-corrected visual acuity (BCVA) was 20/25 OD and 20/40 OS with rigid gas-permeable contact lenses. Due to contact lens intolerance in the OS and lack of custom-fit scleral lenses at the time, 2 ring segments (Ferrara, AJL Ophthalmic, Inc.) with an arc length of 160 degrees and 300 μm in size were implanted at a depth of 320 μm. Within 1 week, severe hydrops and ICRS migration emerged. Medical treatment provided resolution of hydrops and then ICRS reimplantation was performed without further complications, resulting in contact lens tolerance alongside a BCVA of 20/40 OS. Conclusions: Corneal hydrops is a challenging complication in ICRS implantation due to its infrequent occurrence and the severity of its potential sequelae. Prompt medical treatment and close follow-up are essential to obtain the best outcome in these instances. [ABSTRACT FROM AUTHOR]