Quality of life assessment for nuclear, cortical, posterior subcapsular patients before and after cataract surgery / Evaluación de la calidad de vida de pacientes nucleares, corticales y subcapsulares posteriores antes y después de la cirugía de cataratas

Purpose: The impact of visual outcomes of cataract surgery can be measured using a questionnaire. The aim of our study was to evaluate how patient quality of life changes after cataract surgery and if there are differences between the responses of patients with nuclear, cortical, and posterior subcapsular cataracts, which has not been studied before. Method: We studied 210 cataract patients who were divided into 3 cataract groups based on their cataract type: nuclear (n = 80), cortical (n = 70), and posterior subcapsular (PSC) (n = 60). The patients completed the Visual Function Index (VF-14) questionnaire before, 2 weeks and 1 month after bilateral cataract surgery. The results were analysed using one-way ANOVA (significance level 5 %) and were compared over time and between the cataract groups. Results: Before the cataract surgery, cortical cataract patients had the lowest questionnaire score compared to nuclear and posterior subcapsular cataract groups (p = 0.08). After cataract surgery, cortical cataract patients experienced the greatest improvement in near distance daily activities, while PSC cataract patients experienced the greatest improvement in far distance daily activities (p = 0.38). Before surgery, nuclear cataract patients had the highest questionnaire scores compared to the other cataract groups (p = 0.08). Conclusion: At the 1 month follow-up, there were no statistically significant differences in questionnaire scores between the cataract groups for any of the questions. Overall, cortical cataract patients showed a trend to experience the greatest subjective improvement in quality of life after cataract removal, followed by nuclear and posterior subcapsular patients.(AU)

Cataract-1K Dataset for Deep-Learning-Assisted Analysis of Cataract Surgery Videos.

In recent years, the landscape of computer-assisted interventions and post-operative surgical video analysis has been dramatically reshaped by deep-learning techniques, resulting in significant advancements in surgeons' skills, operation room management, and overall surgical outcomes. However, the progression of deep-learning-powered surgical technologies is profoundly reliant on large-scale datasets and annotations. In particular, surgical scene understanding and phase recognition stand as pivotal pillars within the realm of computer-assisted surgery and post-operative assessment of cataract surgery videos. In this context, we present the largest cataract surgery video dataset that addresses diverse requisites for constructing computerized surgical workflow analysis and detecting post-operative irregularities in cataract surgery. We validate the quality of annotations by benchmarking the performance of several state-of-the-art neural network architectures for phase recognition and surgical scene segmentation. Besides, we initiate the research on domain adaptation for instrument segmentation in cataract surgery by evaluating cross-domain instrument segmentation performance in cataract surgery videos. The dataset and annotations are publicly available in Synapse.

The surgical management of a patient with Fuchs endothelial dystrophy and cataracts.

Objective: To report the two different surgical approaches in the case of a patient with Fuchs endothelial dystrophy with low endothelial cell count and advanced cataracts. Methods: The chosen surgical approach differed between eyes, with the right eye undergoing a combined approach consisting of cataract surgery, intraocular lens implantation, and penetrating keratoplasty in 2022. One year later, for the left eye, a different approach was decided: cataract surgery followed by Descemet membrane endothelial keratoplasty (DMEK). The Descemet membrane graft was prepared by the surgeon using the liquid bubble technique. AS-OCT was used to monitor the patient before and after surgery. Results: Visual recovery was excellent for both eyes, however, visual acuity improved quickly in the left eye (DMEK), while, in the right eye (PK), the best corrected visual acuity was reached after several months post-surgery. Conclusion: Advanced stages of Fuchs dystrophy patients will most likely need corneal transplantation. Each type of corneal transplantation procedure comes with unique challenges, both intraoperative and postoperative. DMEK is a very good treatment option for patients with Fuchs endothelial dystrophy, with excellent visual recovery and good graft survival at the 10-year mark. Abbreviations: DMEK = Descemet membrane endothelial keratoplasty, PK = penetrating keratoplasty, AS-OCT = anterior segment optical coherence tomography, FECD = Fuchs endothelial corneal dystrophy, BCVA = best corrected visual acuity, US = ultrasound, CDE = cumulative dissipated energy, IOL = intraocular lens.

Sterile endophthalmitis after intravitreal injection of triamcinolone acetonide: case report and literature review.

Objectives: The first purpose is to present the diagnosis and therapeutic approach in a patient with sterile endophthalmitis associated with triamcinolone acetonide injection. The secondary objective is to assess the incidence of this complication and to summarize the risk factors described in the literature. Case presentation: A 76-year-old male patient presented for painless, unilateral, decreased visual acuity, four days after cataract surgery and simultaneously intravitreal triamcinolone acetonide injection for diabetic macular edema in the right eye. The diagnosis of sterile endophthalmitis was made. Eight days after the presentation, the symptoms subsided, the maximum corrected visual acuity reaching that before the procedures. Discussions: The incidence of sterile endophthalmitis varies in the literature between 0% and 23.8%. Visual prognosis is good, although the pathogenesis is not fully understood. Preservatives in injectable solutions have been suggested, however, there are studies in which inflammation was also present with preservative-free products. The particle size of triamcinolone was analyzed, demonstrating an association between smaller particles and an increased frequency of adverse reactions of this type. History of uveitis, posterior capsule rupture following cataract surgery, and Irvine-Gass syndrome are other associations described. Conclusion: The physiopathological mechanism of sterile endophthalmitis is not fully understood. However, the visual prognosis is good, the final vision being dependent on the underlying pathology.

Clinical evaluation of ophthalmic findings in active, amateur, adult, competitive male boxers in India.

Background: In the popular fighting sport of boxing, opponents strike each other above the belt line in the face, chest, and belly. The physical parts most exposed are therefore the nose and eyes. In amateur boxing, fights go only three rounds - three minutes for men and one minute for women - with a one-minute break in between. They wear gloves, but the head protection used in the men's game has been removed by AIBA due to the high likelihood of concussion when using head protection. Because chronic ocular changes may take longer than the expected short-term effects, this study included at least 3 years of competitive sports participation. Study design and setting: Institutional-based cross-sectional study. Materials and methods: To evaluate ophthalmic outcomes, 200 eyes of 100 active amateur, adult, and competitive male boxers were studied. Results: Of the 100 boxers, 51 had ophthalmic changes in at least one eye, and 49 had normal eyes. The average age of boxers was 24.98 years. The average duration of boxing training was 7.04 years. Healed eyelid scars, subconjunctival hemorrhages, conjunctival papillae, traumatic mydriasis, posterior synechiae, angulation abnormalities, traumatic cataracts, lens subluxation, increased intraocular pressure, and peripapillary atrophy were observed on the ocular side. None of these could be attributed to boxing. Conclusion: Boxing-related eye injuries are common in India and the most common vision-threatening eye abnormalities include traumatic cataracts, lens subluxation, and angle abnormalities. Surprisingly, no macular lesions were found on physical examination and OCT. Additional studies with a larger number of boxers will be needed to evaluate and prevent clinical symptoms. All boxers should have a complete eye exam regularly. Abbreviations: AIBA = Association Internationale de Boxe Amateur, OCT = Optical Coherence Tomography.

IGF-1 rs6218 polymorphisms modulate the susceptibility to age-related cataract.

Background: Single nucleotide polymorphisms (SNPs), as the most abundant form of DNA variation in the human genome, contribute to age-related cataracts (ARC) development. Apoptosis of lens epithelial cells (LECs) is closely related to ARC formation. Insulin-like growth factor 1 (IGF1) contributes to cell apoptosis regulation. Moreover, IGF1 was indicated to exhibit a close association with cataract formation. Afterward, an investigation was conducted to examine the correlation between polymorphisms in IGF1 and the susceptibility to ARC. Methods: The present investigation was a case-control study. Venous blood draws were collected from the participants for DNA genotyping. Lens capsule samples were collected to detect mRNA and apoptosis. TaqMan RT-PCR was used to detect IGF1 polymorphism genotypes and qRT PCR was used to detect IGF1 mRNA levels in LECs. LEC apoptosis was evaluated through flow cytometry. The chi-square test was used to compare differences between ARCs and controls of each SNP. Results: We found that the G allele frequency in the IGF1-rs6218 was higher in the ARCs than in the controls. Furthermore, it was observed that the rs6218 GG genotype exhibited a positive correlation to elevated levels of IGF1 mRNA in LECs. The IGF1 mRNA in the LECs and the apoptosis of LECs in nuclear type of ARCs (ARNC) was higher than the controls. Conclusion: The susceptibility to ARC was related to IGF1-rs6218 polymorphism, and this polymorphism is associated with IGF1 expression at the mRNA level. Moreover, apoptosis in LECs of ARNCs was found to be increased.

Artificial Intelligence in Cataract Surgery: A Systematic Review.

Purpose: The purpose of this study was to assess the current use and reliability of artificial intelligence (AI)-based algorithms for analyzing cataract surgery videos. Methods: A systematic review of the literature about intra-operative analysis of cataract surgery videos with machine learning techniques was performed. Cataract diagnosis and detection algorithms were excluded. Resulting algorithms were compared, descriptively analyzed, and metrics summarized or visually reported. The reproducibility and reliability of the methods and results were assessed using a modified version of the Medical Image Computing and Computer-Assisted (MICCAI) checklist. Results: Thirty-eight of the 550 screened studies were included, 20 addressed the challenge of instrument detection or tracking, 9 focused on phase discrimination, and 8 predicted skill and complications. Instrument detection achieves an area under the receiver operator characteristic curve (ROC AUC) between 0.976 and 0.998, instrument tracking an mAP between 0.685 and 0.929, phase recognition an ROC AUC between 0.773 and 0.990, and complications or surgical skill performs with an ROC AUC between 0.570 and 0.970. Conclusions: The studies showed a wide variation in quality and pose a challenge regarding replication due to a small number of public datasets (none for manual small incision cataract surgery) and seldom published source code. There is no standard for reported outcome metrics and validation of the models on external datasets is rare making comparisons difficult. The data suggests that tracking of instruments and phase detection work well but surgical skill and complication recognition remains a challenge for deep learning. Translational Relevance: This overview of cataract surgery analysis with AI models provides translational value for improving training of the clinician by identifying successes and challenges.

Clinical Experience of Using a Combination of Dexamethasone and Levofloxacin After Cataract Surgery.

Background: Where routine prophylactic antibiotics have been adopted following cataract surgery, rates of endophthalmitis have been decreasing. Intracameral and topical antibiotics are currently used to prevent endophthalmitis after cataract surgery. When applying topical antibiotics, there are different recommendations on the frequency and duration of therapy. The development of bacterial resistance to the excessive and long-term use of antibiotics is a growing problem worldwide. The goal is to achieve a good antibiotic effect with the shortest possible use of antibiotics. Objective: The aim of this study was to compare the effectiveness of a new combination therapy of dexamethasone and levofloxacin for seven days after cataract surgery with the previous regimen of dexamethasone, neomycin sulfate, and polymyxin B, which was given for 21 days. Methods: A retrospective analysis of medical records and administered a questionnaire was conducted to assess the effectiveness of postoperative therapy in our cataract surgery patients. The study involved 52 patients who underwent surgery within the last year, performed by a single surgeon at our institution. The findings can help us improve the quality of care we provide and optimize our patients' overall quality of life. Results: We conducted an in-depth study on 52 individuals who underwent cataract surgery at our institution. The prescribed therapeutic regimen for the participants included administering Ducressa solution four times daily for the first seven days and Maxidex solution three times daily for the subsequent 14 days. The study found that none of the participants experienced complications after surgery, and all found it easy to instill the medication. The prescribed regimen effectively managed the postoperative recovery of the participants, and the medication was well-tolerated. Conclusion: Our research found that a new combination of levofloxacin and dexamethasone, when used topically, may require a shorter treatment period, reducing the risk of antibiotic resistance and providing a safe alternative for endophthalmitis prevention.

Management after cataract surgery for patients with diabetic retinopathy: a systematic review and meta-analysis.

PURPOSE: To evaluate the safety and effectiveness of various treatment modalities in patients with diabetic retinopathy (DR) who underwent cataract surgery. METHODS: A comprehensive search for randomized controlled trials (RCTs) was conducted using the PubMed, Embase, Cochrane Library, and CNKI databases up to December 22, 2021. The safety and efficacy of treatment modalities were assessed using the risk ratio (RR) to compare the progression of DR and the mean difference to evaluate the best corrected visual acuity (BCVA) and macular thickness (MT). RESULTS: The meta-analysis of the RCTs revealed that anti-VEGF (anti-vascular endothelial growth factor) drugs significantly reduced the progression of DR [RR: 0.37 (95%CI 0.19, 0.70), P = 0.002] and improved BCVA [mean difference = - 0.06 (- 0.12, - 0.01), P = 0.03] in patients with pre-existing DR who underwent cataract surgery. Steroid drugs also showed a significant reduction in macular thickness [mean difference = - 55.63 (- 90.73, - 20.53), I2 = 56%, P = 0.002] in DR patients two weeks after cataract surgery compared to the control group. The safety profiles of different management options did not differ significantly. CONCLUSION: The present meta-analysis suggests that anti-VEGF drugs can effectively slow down the progression of diabetic retinopathy, improve BCVA, and reduce MT in DR patients who underwent cataract surgery. Steroid drugs also show promise in reducing MT. However, further studies with larger sample sizes are required to compare the efficacy and safety of different management options in a multi-center clinical setting.

Evaluation of visual outcomes with toric intraocular lens implantation using digital marker during cataract surgery.

Objectives: To assess the visual improvement and mean residual astigmatism in patients who underwent cataract surgery with toric intraocular lens. METHODS: The retrospective, observational study was conducted at the Department of Ophthalmology, Aga Khan University Hospital, Karachi, and comprised data from January 1, 2018, to December 31, 2020, related to adult patients who had regular astigmatism of at least 0.75D and underwent cataract surgery with toric intraocular lens implantation using a digital marker. The patients were followed up on post-operative days 1, 7, 30, 90 and 180. Along with age, the degree of astigmatism was noted. The visual acuity was calculated pre- and post-operatively. The mean residual astigmatism was then noted for all patients post-operatively. Data was analysed using SPSS 22. RESULTS: The sample comprised 240 eyes of 177 patients; 99(55.9%) males and 78(44.1%) females. The mean age of the sample was 62.5±10.6 years. The mean unaided visual acuity improved post-operatively from 0.57±0.38 to 0.07±0.22 at 90 days. At the 30-day follow-up, mean residual astigmatism had reduced from 1.52±0.84 to 0.01±0.09 (p<0.001). The mean intraocular lens rotation from the intended axis was 0.73°±0.92° on day 30. CONCLUSIONS: Toric intraocular lens implantation using a digital marker could effectively reduce the post-operative cylinder, and improve the unaided visual acuity following cataract surgery.

Association of autoimmune and allergic diseases with senile cataract: a bidirectional two-sample Mendelian randomization study.

Background: Many observational studies have been reported that patients with autoimmune or allergic diseases seem to have a higher risk of developing senile cataract, but the views are not consistent. In order to minimize the influence of reverse causality and potential confounding factors, we performed Mendelian Randomization (MR) analysis to investigate the genetic causal associations between autoimmune, allergic diseases and senile cataract. Methods: Single nucleotide polymorphisms associated with ten common autoimmune and allergic diseases were obtained from the IEU Open genome-wide association studies (GWAS) database. Summary-level GWAS statistics for clinically diagnosed senile cataract were obtained from the FinnGen research project GWAS, which consisted of 59,522 individuals with senile cataracts and 312,864 control individuals. MR analysis was conducted using mainly inverse variance weighted (IVW) method and further sensitivity analysis was performed to test robustness. Results: As for ten diseases, IVW results confirmed that type 1 diabetes (OR = 1.06; 95% CI = 1.05-1.08; p = 2.24×10-12), rheumatoid arthritis (OR = 1.05; 95% CI = 1.02-1.08; p = 1.83×10-4), hypothyroidism (OR = 2.4; 95% CI = 1.42-4.06; p = 1.12×10-3), systemic lupus erythematosus (OR = 1.02; 95% CI = 1.01-1.03; p = 2.27×10-3), asthma (OR = 1.02; 95% CI = 1.01-1.03; p = 1.2×10-3) and allergic rhinitis (OR = 1.07; 95% CI = 1.02-1.11; p = 2.15×10-3) were correlated with the risk of senile cataract. Celiac disease (OR = 1.04; 95% CI = 1.01-1.08; P = 0.0437) and atopic dermatitis (OR = 1.05; 95% CI = 1.01-1.10; P = 0.0426) exhibited a suggestive connection with senile cataract after Bonferroni correction. These associations are consistent across weighted median and MR Egger methods, with similar causal estimates in direction and magnitude. Sensitivity analysis further proved that these associations were reliable. Conclusions: The results of the MR analysis showed that there were causal relationships between type 1 diabetes, rheumatoid arthritis, hypothyroidism, systemic lupus erythematosus, asthma, allergic rhinitis and senile cataract. To clarify the possible role of autoimmune and allergy in the pathophysiology of senile cataract, further studies are needed.

The importance of the fourth Greek key motif of human γD-crystallin in maintaining lens transparency-the tale told by the tail.

Purpose: Congenital cataract affects 1-15 per 10,000 newborns worldwide, and 20,000-40,000 children are born every year with developmental bilateral cataracts. Mutations in the crystallin genes are known to cause congenital cataracts. Crystallins, proteins present in the eye lens, are made up of four Greek key motifs separated into two domains. Greek key motifs play an important role in compact folding to provide the necessary refractive index and transparency. The present study was designed to understand the importance of the fourth Greek key motif in maintaining lens transparency by choosing a naturally reported Y134X mutant human γD- crystallin in a Danish infant and its relationship to lens opacification and cataract. Methods: Human γD-crystallin complementary DNA (cDNA) was cloned into the pET-21a vector, and the Y134X mutant clone was generated by site-directed mutagenesis. Wild-type and mutant proteins were overexpressed in the BL21 DE3 pLysS cells of E. coli. Wild-type protein was purified from the soluble fraction using the ion exchange and gel filtration chromatography methods. Mutant protein was predominantly found in insoluble fraction and purified from inclusion bodies. The structure, stability, aggregational, and amyloid fibril formation properties of the mutant were compared to those of the wild type using the fluorescence and circular dichroism spectroscopy methods. Results: Loss of the fourth Greek key motif in human γD-crystallin affects the backbone conformation, alters the tryptophan micro-environment, and exposes a nonpolar hydrophobic core to the surface. Mutant is less stable and opens its Greek key motifs earlier with a concentration midpoint (CM) of unfolding curve of 1.5 M compared to the wild type human γD-crystallin (CM: 2.5 M). Mutant is capable of forming self-aggregates immediately in response to heating at 48.6 °C. Conclusions: Loss of 39 amino acids in the fourth Greek key motif of human γD-crystallin affects the secondary and tertiary structures and exposes the hydrophobic residues to the solvent. These changes make the molecule less stable, resulting in the formation of light-scattering particles, which explains the importance of the fourth Greek key in the underlying mechanism of opacification and cataract.

Corneal endothelial changes seven years after phacoemulsification cataract surgery.

PURPOSE: To evaluate long-term postoperative corneal changes after phacoemulsification cataract surgery. METHODS: Twenty patients who participated in a previous study regarding corneal endothelial changes after phacoemulsification cataract surgery were examined after 7 years. The patients were divided in three groups based on their initial increase in central corneal thickness day one after the surgery: < 5% increase, 6-20% increase and ≥ 20% increase. The primary outcome measures were corneal endothelial cell loss (ECL), endothelial cell count (ECC) and endothelial morphology. RESULTS: After 7 years, a difference in cell loss between the groups was observed, except for groups 1 and 2. Endothelial cell count (ECC) differed significantly between groups 1 and 3 at 3 months. At 7 years, there was no difference in ECC between the three groups. Cell loss was found exclusively in group 1 between 3 months and 7 years. Endothelial cell morphology showed a converging pattern between 3 months and 7 years. CONCLUSION: After phacoemulsification cataract surgery, long-term ECC and morphology appear to converge towards a comparable steady state regardless of initial corneal swelling and endothelial cell loss.

Functional Approach to IOL Selection in Eyes With Combined Cataract and Keratoconus With an Option for Refractive Lens Exchange.

PURPOSE: To evaluate spherical intraocular lens (IOL) implantation for cataracts in keratoconic eyes followed by optional refractive toric lens exchange to improve uncorrected visual acuity. METHODS: This retrospective study evaluated cataract surgery outcomes in keratoconic eyes. Eyes treated with a spherical IOL targeted for -2.00 diopters (D) either achieved acceptable manifest refraction and desired exchange with a toric IOL (Group 1); achieved satisfactory manifest refraction and chose to use spectacles or contact lenses (Group 2); or did not achieve acceptable refraction and used contact lenses (Group 3). Group 4 had single-stage toric IOL implantation with plano target. Corrected and uncorrected distance visual acuity (CDVA and UDVA) and keratometry were analyzed. RESULTS: Groups 1 to 4 had 18, 23, 18, and 26 eyes, respectively. A staged toric exchange resulted in significantly better (P = .02) UDVA (mean: 0.15 logMAR; 20/25 Snellen) than initial toric IOL implantation (0.24 logMAR; 20/30 Snellen). All toric IOL exchange eyes achieved 20/30 or better CDVA and 94% had 20/40 or better UDVA. Mean manifest cylinder significantly decreased from 3.39 D before lens exchange to 1.10 D postoperatively. CONCLUSIONS: Initial implantation of a spherical IOL in keratoconic eyes allows basing toric calculations on the manifest refraction, which may be more reliable than keratometry measurements in keratoconic eyes. UDVA after staged toric IOL exchange was significantly better than after initial toric IOL implantation. Importantly, by staging use of toric lenses, the authors avoided cases where patients required a rigid contact lens after a toric IOL was implanted. [J Refract Surg. 2024;40(4):e207-e217.].

Vitreous hyper-reflective dots and the macular thickness after cataract surgery.

PURPOSE: To assess the association between vitreous hyper-reflective dots (VHD) and the macular thickness changes following uneventful phacoemulsification. METHODS: In this prospective cohort study optical coherence tomography (OCT) examinations were performed preoperatively and 1 week, 1 month and 3 months postoperatively in patients undergoing cataract surgery. OCT images were analyzed for retinal central subfield thickness (CST) and preretinal VHDs. Surgeries were recorded for the assessment of lens fragments in the space of Berger. RESULTS: 111 eyes of 97 patient were enrolled of whom 69 (62.2%) were female. VHDs were seen in 25 eyes (22.5%) at week 1; in 21 eyes (18.9%) at month 1 and in 3 eyes (2.7%) at month 3. In all eyes with VHDs retro-capsular lens fragments were visible immediately after phacoemulsification. The number of VHDs significantly decreased over the postoperative period. There was a moderate correlation between the number of VHDs and CST at 1 month (r = 0.426, p<0.001). In eyes with VHD the CST averaged 238.8±17.6 µm (214-266) at 1 week; 276.1±63.5 µm (231-481) at 1 month and 285.1±122.3 µm (227-785) at 3 months. In eyes with no detectable VHDs CST averaged 235.9±23.3 µm (192-311) at 1 week; 240.1±21.6 µm (200-288) at 1 month and 242.2±21.3 µm (205-289) at 3 months. Although the differences among the assessment points were relatively low, there was a significant difference in general (p<0.001, Friedman test). CONCLUSION: In conclusion, VHDs seem to cause macular thickening throughout the postoperative course. The origin of VHDs is still unknown; however, they presumably represent lens fragments that provoke subclinical inflammation.

Evaluation of changes of anterior segment parameters in patients with pseudoexfoliation syndrome after cataract surgery using anterior segment optical coherence tomography.

The aim of the study was to compare the anterior segment parameters after cataract surgery in pseudoexfoliation syndrome (PEX) and control eyes. We conducted a prospective comparative study of 36 eyes (PEX group), 16 eyes (PEXG group) and 46 eyes (control group) of 98 patients after phacoemulsification with intraocular lens implantation. Before surgery, 1 week, 1 month and 3 months postoperatively, anterior chamber parameters were evaluated by swept source anterior segment optical coherence tomography (AS-OCT). Anterior chamber depth (ACD), angle opening distance (AOD500/750), trabecular-iris space area (TISA500/750), trabecular-iris angle (TIA500/750) and lens vault (LV) were assessed at each study visit. Preoperatively, ACD, AOD500/750 and TISA500/750 were significantly smaller, while LV was significantly greater in PEX and PEXG eyes than in controls. 3 months postoperatively all irido-corneal parameters and ACD were significantly greater in all study groups without intergroup differences. ACD and LV significantly increased in PEX group between 1 and 3 months after surgery while being stable in control group. Relative increases in ACD, AOD500, TISA750, TIA500/750 were significantly higher in PEX and PEXG groups than in controls. Our study finds that ACD and iridocorneal parameters in AS-OCT demonstrated significantly greater relative increases 3 months after phacoemulsification in PEX and PEXG groups than in control eyes. Significantly greater deepening of anterior chamber and opening of the irido-corneal angle may be a reason for different refractive outcomes and IOP control in patients with PEX and PEXG after routine cataract surgery.

Using generative AI to investigate medical imagery models and datasets.

BACKGROUND: AI models have shown promise in performing many medical imaging tasks. However, our ability to explain what signals these models have learned is severely lacking. Explanations are needed in order to increase the trust of doctors in AI-based models, especially in domains where AI prediction capabilities surpass those of humans. Moreover, such explanations could enable novel scientific discovery by uncovering signals in the data that aren't yet known to experts. METHODS: In this paper, we present a workflow for generating hypotheses to understand which visual signals in images are correlated with a classification model's predictions for a given task. This approach leverages an automatic visual explanation algorithm followed by interdisciplinary expert review. We propose the following 4 steps: (i) Train a classifier to perform a given task to assess whether the imagery indeed contains signals relevant to the task; (ii) Train a StyleGAN-based image generator with an architecture that enables guidance by the classifier ("StylEx"); (iii) Automatically detect, extract, and visualize the top visual attributes that the classifier is sensitive towards. For visualization, we independently modify each of these attributes to generate counterfactual visualizations for a set of images (i.e., what the image would look like with the attribute increased or decreased); (iv) Formulate hypotheses for the underlying mechanisms, to stimulate future research. Specifically, present the discovered attributes and corresponding counterfactual visualizations to an interdisciplinary panel of experts so that hypotheses can account for social and structural determinants of health (e.g., whether the attributes correspond to known patho-physiological or socio-cultural phenomena, or could be novel discoveries). FINDINGS: To demonstrate the broad applicability of our approach, we present results on eight prediction tasks across three medical imaging modalities-retinal fundus photographs, external eye photographs, and chest radiographs. We showcase examples where many of the automatically-learned attributes clearly capture clinically known features (e.g., types of cataract, enlarged heart), and demonstrate automatically-learned confounders that arise from factors beyond physiological mechanisms (e.g., chest X-ray underexposure is correlated with the classifier predicting abnormality, and eye makeup is correlated with the classifier predicting low hemoglobin levels). We further show that our method reveals a number of physiologically plausible, previously-unknown attributes based on the literature (e.g., differences in the fundus associated with self-reported sex, which were previously unknown). INTERPRETATION: Our approach enables hypotheses generation via attribute visualizations and has the potential to enable researchers to better understand, improve their assessment, and extract new knowledge from AI-based models, as well as debug and design better datasets. Though not designed to infer causality, importantly, we highlight that attributes generated by our framework can capture phenomena beyond physiology or pathophysiology, reflecting the real world nature of healthcare delivery and socio-cultural factors, and hence interdisciplinary perspectives are critical in these investigations. Finally, we will release code to help researchers train their own StylEx models and analyze their predictive tasks of interest, and use the methodology presented in this paper for responsible interpretation of the revealed attributes. FUNDING: Google.

Re-Descemet Membrane Endothelial Keratoplasty (DMEK) con preservación del injerto original tras free roll en cámara anterior: a propósito de un caso / Re-descemet membrane endothelial keratoplasty (DMEK) with preservation of the original graft after free-roll in the anterior chamber: a case report

Introducción: Las queratoplastias lamelares han supuesto un gran impacto en el manejo del edema corneal por disfunción endotelial. Las técnicas de trasplante mínimamente invasivo como la Descemet Membrane Endothelial Keratoplasty (DMEK) han permitido reducir la morbilidad que suponía la realización de una queratoplastia penetrante en este tipo de pacientes. Aun así, se trata de técnicas complejas que no están exentas de complicaciones, y que requieren una larga línea de aprendizaje quirúrgico y una aún más exigente experiencia en el manejo postoperatorio.Caso clínicoUna mujer de 89 años afecta de distrofia endotelial de Fuchs e intervenida de cirugía combinada de catarata y DMEK, presentó a las 24h de la intervención un edema estromal de predominio inferior y un despegamiento sectorial del injerto. Tras un re-bubbling en consultas y 4 días más tarde, se observó el injerto enrollado y libre en cámara anterior.Se intervino de re-DMEK con preservación del injerto original tras 24h, con desepitelización para optimizar la visualización. Se tiñó el injerto con azul tripán y se protegió el estroma posterior con aire. Se reimplantó el injerto bajo maniobras intraoculares y con burbuja de aire.A las 24h de la cirugía se observó el injerto adherido, con una gran disminución del edema estromal. Un mes después, la paciente presentaba una córnea transparente, una persistente adhesión completa del injerto y una agudeza visual de 0,9.ConclusiónEl hallazgo del free roll en cámara anterior tras cirugía de DMEK constituye la forma más compleja de despegamiento del injerto. El edema corneal, así como la disposición de las diferentes estructuras intraoculares son condicionantes a tener en cuenta para la resolución quirúrgica de esta complicación. En muchos casos el reposicionamiento quirúrgico del injerto es factible, hecho que implica ahorrar costes sin necesidad de utilizar nuevos tejidos corneales donantes. (AU)

Introduction: Lamellar keratoplasties have had a great impact in the management of corneal edema due to endothelial dysfunction. Minimally invasive transplant techniques such as descemet membrane endothelial keratoplasty (DMEK) have helped to reduce the morbidity involved in performing penetrating keratoplasty in this type of patient. Even so, these are complex techniques that are not free of complications and require a long line of surgical learning and an even more demanding experience in postoperative management.Clinical caseAn 89-year-old woman suffering from Fuchs endothelial dystrophy and undergoing combined cataract and DMEK surgery presented stromal edema predominantly inferior and sectoral detachment of the graft 24h after the intervention. After re-bubbling in consultations and 4 days later, the graft was observed rolled and free in the anterior chamber.She underwent re-DMEK with preservation of the original graft after 24h, with de-epithelialization to optimize visualization. The graft was stained with trypan blue and the posterior stroma was protected with air. The graft was reimplanted under intraocular maneuvers and with an air bubble.Twenty four hours after surgery, the adhered graft was observed, with a great decrease in stromal edema. One month later, the patient had a clear cornea, persistent complete graft adhesion, and visual acuity of 0.9.ConclusionThe discovery of free roll in the anterior chamber after DMEK surgery constitutes the most complex form of graft detachment. Corneal edema as well as the arrangement of the different intraocular structures are conditions to be considered for the surgical resolution of this complication. In many cases, surgical repositioning of the graft is feasible, which means saving costs without the need to use new donor corneal tissues. (AU)