Descemet's membrane endothelial keratoplasty rejection after SARS-COV2 infection or vaccination: 2-year retrospective study.

PURPOSE: To assess the incidence of Descemet's membrane endothelial keratoplasty (DMEK) rejection potentially associated with coronavirus disease 2019 (COVID-19) infection or vaccination, and its association with known rejection risk factors during the first two years of the pandemic. METHODS: This retrospective study included patients with DMEK rejection between January 2020 and December 2021. Diagnostic criteria were based on symptoms, visual acuity, and other clinical assessments. Risk factors for graft rejection were considered, and a telephone survey was conducted to identify possible preceding COVID-19 infection or vaccination. RESULTS: Of 58 patients, 44 were included. Six patients (14%) reported COVID-19 infection, with one immediate endothelial graft rejection (EGR) post-infection. After vaccine availability, 13 of 36 patients had EGR at an average of 2.7 months post-vaccination. Five (38%) had immediate EGR following vaccination, four of which had concomitant risk factors for rejection. CONCLUSION: Although the risk of endothelial graft rejection (EGR) associated with COVID-19 infection or vaccination appears to be extremely low, there may be a causative relationship, especially in patients with pre-existing risk factors for EGR. A temporary increase in anti-rejection treatment following COVID-19 infection or vaccination is recommended, especially in patients with pre-existing risk factors, along with closer monitoring during the subsequent 4 to 8 weeks.

[Blue light and intraocular lenses (IOLs): Beliefs and realities]. / Lumière bleue et implants intraoculaires : croyances et réalités.

The first intraocular lenses (IOLs) used for cataract surgery transmitted both ultraviolet (UV) radiation and visible light to the retina. Colorless UV-blocking IOLs were introduced and rapidly adopted in the 1980s. Yellow-tinted blue-blocking (also known as blue-filtering) IOLs were marketed in the early 1990s. Blue-blocking IOLs were intended to simulate age-related crystalline lens yellowing to reduce the cyanopsia that some patients experienced after cataract surgery. When blue-filtering IOLs were introduced in North America, however, blue-blocking chromophores were advocated as a way to protect patients from age-related macular degeneration (AMD) despite the lack of evidence that normal environmental light exposure causes AMD. The "blue light hazard" is a term that describes the experimental finding that acute, abnormally intense light exposures are potentially more phototoxic to the retina when short rather than long wavelengths are used. Thus, in brief exposures to intense light sources such as welding arcs, ultraviolet radiation is more hazardous than blue light, which is more hazardous than longer wavelength green or red light. International commissions have cautioned that the blue light hazard does not apply to normal indoor or outdoor light exposures. Nonetheless, the hazard is used for commercial purposes to suggest misleadingly that ambient environmental light can cause acute retinal phototoxicity and increase the risk of AMD. Very large epidemiological studies show that blue-blocking IOLs do not reduce the risk or progression of AMD. Additionally, blue-filtering IOLs or spectacles cannot decrease glare disability, because they decrease image and glare illuminance in the same proportion. Blue light is essential for older adults' scotopic photoreception needed to reduce the risk of nighttime falling and related injuries. It is also critical for circadian photoreception that is essential for good health, sleep and cognitive performance. Unfortunately, age-related pupillary miosis, retinal rod and ganglion cell photoreceptor degeneration and decreased outdoor activity all reduce the amount of healthful blue light available to older adults. Blue-restricting IOLs further reduce the available blue light at a time when older adults need it most. Patients and ophthalmologists are exposed to hypothesis-based advertisements for blue-filtering optical devices that suppress short wavelength light critical for vision in dim lighting and for good physical and mental health. Spectacle and intraocular lens selections should be based on scientific fact, not conjecture. Ideal IOLs should improve photoreception rather than limit it permanently. Practice efficiency, surgical convenience and physician-manufacturer relationships may eliminate a patient's opportunity to choose between colorless blue-transmitting IOLs and yellow-tinted, blue-restricting IOLs. Cataract surgeons ultimately determine whether their patients have the opportunity to make an informed choice about their future photoreception.

Success of ChatGPT, an AI language model, in taking the French language version of the European Board of Ophthalmology examination: A novel approach to medical knowledge assessment.

PURPOSE: The purpose of this study was to evaluate the performance of ChatGPT, a cutting-edge artificial intelligence (AI) language model developed by OpenAI, in successfully completing the French language version of the European Board of Ophthalmology (EBO) examination and to assess its potential role in medical education and knowledge assessment. METHODS: ChatGPT, based on the GPT-4 architecture, was exposed to a series of EBO examination questions in French, covering various aspects of ophthalmology. The AI's performance was evaluated by comparing its responses with the correct answers provided by ophthalmology experts. Additionally, the study assessed the time taken by ChatGPT to answer each question as a measure of efficiency. RESULTS: ChatGPT achieved a 91% success rate on the EBO examination, demonstrating a high level of competency in ophthalmology knowledge and application. The AI provided correct answers across all question categories, indicating a strong understanding of basic sciences, clinical knowledge, and clinical management. The AI model also answered the questions rapidly, taking only a fraction of the time needed by human test-takers. CONCLUSION: ChatGPT's performance on the French language version of the EBO examination demonstrates its potential to be a valuable tool in medical education and knowledge assessment. Further research is needed to explore optimal ways to implement AI language models in medical education and to address the associated ethical and practical concerns.

[Epigenetics and myopia: Mechanisms and therapeutic targets]. / Épigénétique et myopie : mécanismes et perspectives thérapeutiques.

The development of myopia is influenced by multiple environmental and genetic factors. A third component, epigenetics, may shed light on some of the relationships between environmental and genetic factors. Epigenetics is defined as the study of modulations of gene activity that can be transmitted over cell divisions without involving mutation of the DNA sequence. Methylation is one of the main mechanisms by which gene expression is decreased. In the context of myopia, the study of epigenetic mechanisms also contributes to the understanding of the involvement of candidate genetic variants. The analysis of metabolic and signalling pathways associated with ocular development enables discussion of the biological significance associated with these candidate genes. A better understanding of epigenetic mechanisms would allow individual risk estimations for myopia and probably targeting of therapeutic interventions at a population level. Measuring the level of DNA methylation at candidate gene sites could be used to monitor the effectiveness of myopia prevention measures such as reducing near work and increasing outdoor activity. More specifically, one could consider activating the methylation of myopia promoter genes or, on the contrary, inhibiting the methylation of myopia repressor genes. Finally, the control of metabolic and signalling pathways could be considered by targeting, for example, the regulation of the G protein signalling pathway (RGS 2) with the expression of the adenosine A2a receptor (AdoRs).

Surgical approaches to autologous limbal stem cell transplantation (LSCT) following severe corneal chemical burns.

Chemical injury of the conjunctiva and cornea are true ocular emergencies and require immediate intervention. They can produce severe, extensive ocular damage, including limbal stem cell deficiency (LSCD), and lead to irreversible visual loss. LSCD can be treated surgically through autologous limbal stem cell transplantation (LSCT). Autologous LSCT can be performed through cultivated limbal epithelial transplantation (CLET) or by direct grafting of limbal epithelial cells through conjunctival-limbal autografting (CLAU) or simple limbal epithelial transplantation (SLET). In this review we provide an overview of each surgical approach. CLET allows for a implantation of a large graft in the recipient eye while preserving donor cells. Its success rate is higher with an increased number of transplanted stem cells; failures tend to occur within the first year. CLAU is performed by directly transplanting autologous limbal stem cells from the patient's healthy eye, reducing the risk of immune rejection. This constitutes a risk for the donor eye, as the removal of stem cells from the fellow eye may lead to LSCD in the donor eye. SLET consists of direct implantation of donor stem cells on an amniotic membrane, thus avoiding the need for ex-vivo expansion. Combinations of CLAU and SLET within a single procedure have also been successfully utilized. Autologous LCST is an effective technique for surgical management of unilateral LCSD. Depending on the patient history and status of the fellow eye, either CLET, CLAU or SLET (including the combination of mini-CLAU and SLET) can be used to restore long-term function and prevent visual impairment.

Non stripping descemet membrane endothelial keratoplasty in difficult cases: A case series.

Endothelial keratoplasty (EK) has been increasingly used instead of penetrating keratoplasty (PK) in the management of post PK graft rejection. Both DSAEK and DMEK involve the surgical removal of the diseased host endothelial cell layer and Descemet's membrane (DM) (descemetorhexis) before transplantation, a technically challenging step, especially in post-PK eyes. Understandably, interest arose when non-stripping DMEK (nDMEK) was described in 2013, and recent studies suggested encouraging results without increased early postoperative failures or complications requiring rebubbling. The purpose of our series was to further study the feasibility and safety of nDMEK and to compare the results with traditional DMEK. This is a single center case series of 3 eyes which underwent nDMEK performed by experienced surgeons (C.P, A.M). Two eyes had nDMEK as a secondary procedure following a failed/rejected PK, while the third case underwent nDMEK on a virgin eye. Undiseased donor DM and a regular host endothelium were required to be eligible for nDMEK. The average change in CCT at last follow-up was -21.2% (±13.3). All required intracameral air injection (rebubbling) within the first few days, with a mean of 2.33 rebubblings per eye, the first one occurring at 6.33±2.52 days after surgery. Non-stripping DMEK surgery appears to be a feasible option, and results are satisfactory at mid to long term. However, in our series, the immediate postoperative period was marked by an increased rebubbling rate. While foreseeable particularly in high-risk cases, surgeons considering this technique should expect a higher risk of early rejection.

Myopic outcomes after excimer laser phototherapeutic keratectomy (PTK).

PURPOSE: To evaluate refractive outcomes following excimer laser phototherapeutic keratectomy (PTK). METHODS: A retrospective non-randomized review of refractive outcomes of 146 consecutive eyes treated with excimer laser PTK at the Rothschild Foundation, Paris, France. Inclusion criteria were all patients undergoing PTK laser using a flying spot excimer laser system (Wavelight Allegretto, Alcon Surgical, Inc.) from October 2016 to June 2018. Exclusion criteria were incomplete data, irregular astigmatism and dystrophies of uncertain diagnosis. Preoperative diagnoses included recurrent corneal erosion syndrome without dystrophy and Cogan corneal dystrophies. The primary outcome measure was the change in spherical equivalent (SEQ) at M1 post PTK. The secondary outcome measure was the creation of a regression equation for predicting refractive outcomes after PTK, by analyzing the effect of ablation depth (AD) and optical zone (OZ) diameter. RESULTS: Fifty-eight eyes of 54 patients were included. The mean OZ was 7.352 mm±0.622. The mean AD was 18.362µm±21.406. At M1 postoperatively, the mean SEQ was -2.485 D±2.628 and mean final SEQ was -1.052 D±1.260. Both OZ and AD were independent variables with significant effects on the final visual outcome. A regression equation for predicting refractive outcomes was established. No complications were observed. CONCLUSION: The Wavelight flying spot excimer laser system produces myopic outcomes following PTK. Both OZ and AD are significant variables. A regression equation was created and may aid in prediction of refractive outcomes following PTK.

[Evaluation of vision quality after laser vision correction in healthcare professionals]. / Évaluation de la qualité de vision après chirurgie réfractive au laser chez les professionnels de santé.

PURPOSE: Healthcare professionals require good quality of vision. The main objective of this study is to evaluate the satisfaction and vision quality after laser vision correction in healthcare professionals. METHODS: This is a monocentric retrospective study. An online 25-question survey was sent to ametropic physicians, surgeons and nurses who underwent corneal refractive surgery with laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) between July 2012 and February 2016. Questionnaire responses were recorded anonymously by the internet survey site. These patients' pre- and postoperative data were analyzed. RESULTS: In total, 2491 laser vision corrections were performed during this time frame. One hundred and fifty-eight patients were healthcare providers; 131 received the survey, and 111 responded. Ninety-nine were surgeons, 60 were medical physicians, and 32 were nurses. Ninety-one percent reported that they were satisfied with their postoperative vision quality, 63.9% even reported an improvement in their quality of vision compared with their corrected preoperative vision, 92.8% reported that they would have the procedure again, and 94.6% would recommend the procedure to a family member or a patient. Visual outcomes showed high levels of efficacy and predictability. CONCLUSION: While healthcare professionals require good quality of vision, those who had undergone laser vision correction reported the same satisfaction as the general population and would recommend the procedure to their family, friends and patients.

[Schnyder's crystalline-like corneal dystrophy: a case report]. / A propos d'un cas évocateur de dystrophie cristalline de Schnyder.

Schnyder's crystalline corneal dystrophy is a rare bilateral hereditary disease with various clinical features. It typically presents as a central disc-like opacification with or without crystalline deposits. We report the case of a particular crystalline-free and ring-like pattern dystrophy resembling Schnyder's corneal dystrophy in an 82-year-old woman. In addition, we describe the aspects of this dystrophy with in vivo confocal microscopy using the Heidelberg Retina Tomograph II-Rostock Cornea Module and with anterior segment optical coherence tomography (OCT-Visante((R))). These techniques can be useful in the diagnosis or the therapeutic process, showing crystalline structures that are not clinically distinguishable or validating the histological localization of the corneal disease.

[Intraocular lens power calculation after keratorefractive surgery]. / Calcul de la puissance de l'implant intraoculaire après chirurgie réfractive cornéenne.

The number of keratorefractive procedures designed to correct refractive errors has dramatically increased over the last few years. The techniques for cataract extraction and intraocular lens implantation have evolved into a refractive surgical procedure as well as an operation to improve best corrected visual acuity and/or spectacle independence. The calculation of intraocular lens power for a desired refractive target can be challenging in post-refractive surgically treated eyes, given the frequent case reports of "refractive surprises" after cataract surgery. After corneal refractive surgery, the direct use of the measured topographic or keratometric values, with no correction, results in less accurate calculation of intraocular lens (IOL) power required for cataract surgery than calculation in virgin eyes. After laser refractive surgery for myopia, this could result in an overestimation of the corneal power and subsequent underestimation of the IOL power, therefore leading to a hyperopic outcome after phacoemulsification. Conversely, after laser refractive surgery for hyperopia, inaccuracy in the keratometric power estimation could result in a myopic outcome after phacoemulsification. Despite current progress in this subject, awareness of the shortcomings of classical methods and suggested strategies to improve accuracy can be valuable to clinicians. This article provides an overview of the possible sources of error in intraocular lens power calculation in post-keratorefractive patients, and reviews the methods to minimize intraocular lens power errors.

[Efficacy of topical 2% cyclosporine A as a steroid-sparing agent in steroid-dependent vernal keratoconjunctivitis]. / Efficacité de la ciclosporine A en collyre à 2% en tant qu'épargneur de corticoïdes dans le traitement de la kératoconjonctivite vernale corticodépendante.

INTRODUCTION: Vernal keratoconjunctivitis (VKC) is responsible for severe conjunctival and corneal inflammation that often requires topical steroids. Steroid dependency is not rare and can lead to unacceptable complications. The aim of this study was to analyze the efficacy of 2% cyclosporine eye drops (CsA) as a steroid-sparing agent in steroid-dependent VKC. PATIENTS AND METHODS: In this noncomparative interventional case series, 18 steroid-dependent VKC patients (17 males, 1 female; mean age, 13 years old) received 2% CsA qid. Topical steroids were associated at decreasing dosage for 1 week and stopped if possible. Efficacy was graded at 1 and 3 months on symptoms, signs and steroid use. Local and systemic tolerability (cyclosporinemia, creatininemia) was also assessed. RESULTS: After 1 month, inflammation was controlled without steroids in 11 cases (61%). Low-dose steroids were still necessary to control the disease in four cases (22%). In three cases (17%), the disease was not controlled despite high-dose steroids. At 3 months, results were similar. All patients whose inflammation was partially controlled or not controlled by CsA had active extraocular atopic diseases. Local and systemic tolerability was excellent. CONCLUSIONS: Topical 2% cyclosporine is inconstantly effective in steroid-dependent VKC. However, this treatment allows for a partial or total reduction of steroids in most cases.

[Assessment of the nerve fiber layer thickness after LASIK using scanning laser polarimetry with variable corneal compensation]. / Mesure de l'épaisseur des fibres nerveuses rétiniennes après LASIK par laser polarimètre à balayage avec compensation cornéenne variable.

AIM: To evaluate the reliability of scanning laser polarimetry with variable corneal compensation after laser-assisted in-situ keratomileusis (LASIK). METHODS: Thirty-six eyes of 18 consecutive patients who had LASIK where included in the study. For each eye, one scanning laser polarimetry with variable corneal compensation (GDxVCC) was performed before LASIK (GDx no 1). One month after surgery, two other scanning laser polarimetry procedures were performed: one used the corneal compensation measured preoperatively (GDx no 2) and one used a new corneal compensation, measured postoperatively (GDx no 3). The values measured preoperatively were compared first to the values obtained postoperatively with GDx no 2, then to the values obtained postoperatively with GDx no 3 (Wilcoxon test). RESULTS: When corneal compensation was re-measured postoperatively (GDx no 3), the measurements were reliable for 35 eyes (97%). We found no significant differences between the preoperative and postoperative values except for the NFI (p=0.032). When the preoperative corneal compensation value was used in the postoperative measurements (GDx no 2), the exam was not reliable for 13 eyes, and it could not be performed at all for two eyes. For the remaining eyes, the values of four parameters were significantly modified: superior thickness (p=0.03), superior ratio (p=0.0005), inferior ratio (p=0.009), and ellipse modulation (p=0.39). The values of the other parameters (average thickness and inferior average) remained unchanged. CONCLUSION: The use of a preoperative customized corneal compensation for the realization of post-LASIK measurements does not provide reliable results. The GDxTMVCC can be considered a reliable tool after LASIK only when the corneal compensation is re-evaluated postoperatively.

[Long-term changes in pupil size after implantation of an Artisan phakic intraocular lens for correction of high myopia]. / Modifications à long terme du diamètre pupillaire après insertion d'un implant phaque Artisan pour la correction des fortes amétropies myopiques.

PURPOSE: To evaluate the long-term changes in pupil size after implantation of an Artisan phakic intraocular lens for correction of high myopia. PATIENTS AND METHODS: Fourteen myopic eyes of seven patients were included in the study. Pupil size was measured under photopic conditions, under scotopic conditions after 10 min of dark adaptation, and after topical medical mydriasis. The pupil size was measured using the eye image of the OPD scan (Nidek). RESULTS: The mean follow-up was 46 months after surgery. The mean photopic pupil diameter was 2.94+/-0.33 mm (range, 2.54-3.6 mm). The diameter of the scotopic pupil remained less than 6.0 mm in all patients (4.68+/-0.59 mm, with maximal pupil diameter of 5.67 mm). The mean pupil diameter after pharmacological dilation was also reduced (5.39+/-1.08 mm; range, 4.19-7.59 mm), with pupil dilation more than 7 mm in only one patient. CONCLUSION: The iris-fixated intraocular lens mechanically limited pupil dilation in our patients. The long-term reduction in pupil size after Artisan phakic intraocular lens implantation may contribute to the maintenance of the quality of vision in scotopic conditions.

[Three-dimensional computer-assisted modeling of the orbital cavity and the eyelids]. / Modélisation informatique tridimensionnelle de la cavité orbitaire et des paupières.

PURPOSE: To develop a virtual model of the orbital cavity and the eyelids using a three-dimensional model. METHODS: Amapi Designer 7 and Carrara 3 Studio (Eovia, Mountain View, CA, USA) software were used to obtain 3D models of the orbital cavity and the eyelids. Three-dimensional creation is divided into two main processes. In the modeling process, a 3D model of the orbit, the arterial supply, and the eyelids are created using polygonal meshes and surgical tools with parametric surfaces. In the rendering process, colors are arbitrarily chosen to make elements in the model easier to read. A virtual camera is adjusted and light sources are created to produce virtual simulations of the orbit and the eyelids. RESULTS: Surgical techniques were illustrated with 3D models. Ptosis surgery (resection of the levator muscle and Müller's muscle conjunctival resection) and the transconjunctival approach to lower eyelid blepharoplasty were described step by step. CONCLUSION: Three-dimensional models have applications in many medical fields, providing representation of anatomical structures. They can be used to depict the anatomy of the orbital region in a realistic way. Three-dimensional computer-generated images are an aid in teaching residents in orbital anatomy and surgery.