The potential influence of the ligament of Wieger on the crystalline lens shape.

This research uses mathematical modelling to evaluate the influence of the ligament of Wieger on the crystalline lens shape at rest, and during accommodation. An axisymmetric model of the anterior segment, including the ligament of Wieger, was created using the finite element method. Different conditions including variations of stiffness and positions of the ligament, with and without the ligament, were tested to see how they affected lens curvature and optical power. Adding the ligament of Wieger to the simulation had a noticeable impact on the optical power of the lens, particularly on the posterior surface power and total power. Ligament stiffness and width significant influenced the accommodative range of the eye by - 0.95D and - 2.39D for ligaments with the same and 3× the stiffness of the capsular bag, respectively. Ligament width and inner diameter had negligible effects on lens thickness but did have significant effects on posterior surface power and accommodation. In this simulation, we found that the ligament of Wieger can significantly affect the lens shape, both at rest and during accommodation, and may need to be considered in lens models.

Cataract surgical training in Europe: European Board of Ophthalmology survey.

PURPOSE: To survey recently graduated European ophthalmologists concerning cataract surgery (CS) training opportunities. SETTING: Countries affiliated to the European Board of Ophthalmology (EBO). DESIGN: Cross-sectional study of anonymous survey results. METHODS: A 23-question online survey was emailed to candidates who sat the EBO Diploma Examination as residents between 2018 and 2022. RESULTS: 821 ophthalmologists from 30 countries completed the survey. The mean residency duration was 4.73 (SD 0.9) years. The mean reported number of entire CS procedures performed was 80.7 (SD 100.6) at the end of residency, but more than 25% of respondents (n = 210) had received no live CS training during their residency. The self-confidence (scale, 1 to 10) to perform a simple case or challenging case, manage posterior capsular rupture, and realize a corneal stitch were rated 4.1, 3.2, 4.2, 2.4, respectively. We observed extensive variation in clinical exposure to CS and self-reported confidence to perform CS between European trainees. Females reported a mean of 18% fewer entire procedures than their male colleagues and were also less confident in their surgical skills (P < .05). Trainees in residency programs longer than 5 years performed fewer procedures and were less confident than trainees in residences of shorter duration (P < .001). The importance of fellowships to complete surgical education was rated 7.7 out of 10. CONCLUSIONS: CS training across European countries lacks harmony. Female ophthalmology trainees continue, as in other specialties, to experience apparent gender bias. European level recommendations seem necessary to raise and harmonize competency-based CS training programs and promote post-residency fellowship training programs.

Development of machine learning models to predict posterior capsule rupture based on the EUREQUO registry.

PURPOSE: To evaluate the performance of different probabilistic classifiers to predict posterior capsule rupture (PCR) prior to cataract surgery. METHODS: Three probabilistic classifiers were constructed to estimate the probability of PCR: a Bayesian network (BN), logistic regression (LR) model, and multi-layer perceptron (MLP) network. The classifiers were trained on a sample of 2 853 376 surgeries reported to the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) between 2008 and 2018. The performance of the classifiers was evaluated based on the area under the precision-recall curve (AUPRC) and compared to existing scoring models in the literature. Furthermore, direct risk factors for PCR were identified by analysing the independence structure of the BN. RESULTS: The MLP network predicted PCR overall the best (AUPRC 13.1 ± 0.41%), followed by the BN (AUPRC 8.05 ± 0.39%) and the LR model (AUPRC 7.31 ± 0.15%). Direct risk factors for PCR include preoperative best-corrected visual acuity (BCVA), year of surgery, operation type, anaesthesia, target refraction, other ocular comorbidities, white cataract, and corneal opacities. CONCLUSIONS: Our results suggest that the MLP network performs better than existing scoring models in the literature, despite a relatively low precision at high recall. Consequently, implementing the MLP network in clinical practice can potentially decrease the PCR rate.

RETINAL FLUORESCEIN ANGIOGRAPHY IN SUSAC SYNDROME: A SHIFTING PATTERN OF ARTERIOLAR WALL HYPERFLUORESCENCE-A REPORT OF TWO CASES.

BACKGROUND: Susac syndrome consists of the triad of encephalopathy, branch retinal artery occlusion, and hearing loss and is believed to be an immune-mediated endotheliopathy. Arteriolar wall hyperfluorescence (AWH) on retinal fluorescein angiography (FA) has been described in the literature as a classic ophthalmic sign for Susac syndrome. In this article, we report a pattern of distally shifting segments of AWH on FA over time that was observed in two cases. METHODS: Two cases of Susac syndrome are presented with an emphasis on FA findings, obtained at frequent intervals during follow-up. RESULTS: In both cases, FA displays a shifting pattern of segments of AWH distal to the localization of the AWH observed on the previous FA. CONCLUSION: In patients with Susac syndrome, FA plays an important role in aiding diagnosis and monitoring the efficacy of treatment and disease activity during follow-up. In these two cases, the angiography revealed how the AWH can migrate along the vessel over time. This is the first published report showing an evolving distally shifting pattern of AWH in patients with Susac syndrome.

Safety of the bag-in-the-lens implantation regarding the development of clinically significant pseudophakic cystoid macular edema: A retrospective case series study.

PURPOSE: To determine the incidence of clinically significant pseudophakic cystoid macular edema (CSPME) after phacoemulsification using the 'bag-in-the-lens' lens (BIL) implantation technique and to examine the influence of associated risk factors for clinically significant pseudophakic macular edema (CSPME), both ocular and systemic. METHODS: This retrospective study included 2419 first-operated eyes of 2419 adults who underwent phacoemulsification cataract surgery using the BIL implantation technique between January 2013 and December 2018 in the Antwerp University Hospital, Belgium. The significance of several risk factors (age, gender, previous history, intra- and postoperative complications) was examined by extraction of electronic medical files. RESULTS: The 3-month incidence of CSPME in the subgroup without risk factors was 0.00% (95% CI: 0.00 -NA). The 3-month incidence of CSPME in the subgroup with risk factors was 0.57% (95% CI 0.22-1.29%). The 3-month incidence of CSPME in the total population of 2419 patients was 0.29% (95% CI: 0.11-0.65%). The risk factors most significantly associated with CSPME included renal insufficiency (hazard ration [HR]: 5.42; 95% CI: 1.69-17.44; P = .014), exudative age-related macular degeneration (HR: 74.50, 95% CI: 25.75-215.6; P < .001) and retinal vein occlusion (HR: 22.48, 95% CI: 4.55-111.02; P = .005). CONCLUSIONS: In the absence of risk factors, the incidence of CSPME was zero. We can conclude that Primary Posterior Continuous Curvilinear Capsulorhexis (PPCCC) does not increase the risk for CSPME. Non-inferiority of the BIL implantation regarding the development of CSPME, relative to the traditional 'lens-in-the-bag' (LIB) implantation, confirms that BIL is a safe surgical technique. This study also illustrates a previously undescribed risk factor for developing CSPME, namely renal insufficiency.

Anesthesia techniques and the risk of complications as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery.

PURPOSE: To determine the trends in anesthesia techniques for cataract surgery over the past decade and their relationship to surgical complications. SETTING: Clinics affiliated with the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO). DESIGN: Retrospective cross-sectional register-based study. METHODS: Variables include patient demographics, visual acuity, ocular comorbidities, surgery characteristics, intraoperative complications, and postoperative complications for the study period from January 2008, to December 2018. The anesthesia methods registered in the EUREQUO and included in the study are topical, combined topical and intracameral, sub-Tenon, regional, and general anesthesia. Multivariate logistic regression models for each complication were constructed to estimate the adjusted odds ratio (OR) and 95% CIs. RESULTS: Complete data were available of 1 354 036 cataract surgeries. Topical anesthesia increased significantly over time (from 30% to 76%, P < .001). Sub-Tenon and regional anesthesia decreased (from 27% and 38% to 16% and 6%, respectively, P < .001), and general and combined topical and intracameral anesthesia remained stable (around 2%). Sub-Tenon (OR, 0.80; 95% CI, 0.71-0.91, P < .001), regional (0.74; 95% CI, 0.71-0.78, P < .001), general (0.53; 95% CI, 0.50-0.56, P < .001), and intracameral anesthesia (0.76; 95% CI, 0.64-0.90, P = .001) carried a significantly decreased risk of posterior capsule rupture (PCR), with and without dropped nucleus, compared with topical anesthesia. The risk of endophthalmitis was significantly lower with regional anesthesia compared with topical anesthesia (OR, 0.60; 95% CI, 0.44-0.82, P = .001). CONCLUSIONS: The use of topical anesthesia for cataract surgery increased over time. Topical anesthesia is associated with an increased risk of PCR with and without dropped nucleus, and endophthalmitis.

Wave-like calcification on the posterior surface of an acrylic hydrophilic bag-in-the-lens (BIL) implant.

Purpose: To report secondary opacification of a hydrophilic bag-in-the-lens (BIL) which is a rare manifestation that can happen years after initial surgery. Observations: We describe a case of a prominent wave-like, rippled opacification on the posterior surface of the BIL. The opacification was composed of calcium deposits and seems to start in the periphery as a ring and progresses to the centre of the posterior surface. Due to the specific design of the BIL, there is direct contact between the BIL and the posterior chamber, both with the space of Berger, and the anterior hyaloid, particularly in this very hyperopic eye. Conclusions and importance: Abnormal fluid flow and stagnation in an unusual retrolenticular space is a possible explanation for this unusual pattern of posterior surface opacification.

Laser-induced nanobubbles safely ablate vitreous opacities in vivo.

In myopia, diabetes and ageing, fibrous vitreous liquefaction and degeneration is associated with the formation of opacities inside the vitreous body that cast shadows on the retina, appearing as 'floaters' to the patient. Vitreous opacities degrade contrast sensitivity function and can cause notable impairment in vision-related quality of life. Here we introduce 'nanobubble ablation' for safe destruction of vitreous opacities. Following intravitreal injection, hyaluronic acid-coated gold nanoparticles and indocyanine green, which is widely used as a dye in vitreoretinal surgery, spontaneously accumulate on collagenous vitreous opacities in the eyes of rabbits. Applying nanosecond laser pulses generates vapour nanobubbles that mechanically destroy the opacities in rabbit eyes and in patient specimens. Nanobubble ablation might offer a safe and efficient treatment to millions of patients suffering from debilitating vitreous opacities and paves the way for a highly safe use of pulsed lasers in the posterior segment of the eye.

Outcomes of cataract surgery complicated by posterior capsule rupture in the European Registry of Quality Outcomes for Cataract and Refractive Surgery.

PURPOSE: To analyze the outcomes of cataract surgery complicated by posterior capsule rupture (PCR). SETTING: European clinics affiliated to the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO). DESIGN: Retrospective cross-sectional register-based study. METHODS: Data were retrieved from the EUREQUO between January 1, 2008, and December 31, 2018. The database consists of data on demographics, intraoperative complications such as PCR, type of intraocular lens (IOL) material, postoperative refraction, corrected distance visual acuity (CDVA), and postoperative complications. RESULTS: 1 371 743 cataract extractions with complete postoperative data were reported in the EUREQUO. In 12 196 cases (0.9%), PCR was reported. After PCR, patients were more likely to receive a poly(methyl methacrylate) IOL (5.2% vs 0.4%, respectively) or no IOL (1.1% vs 0.02%, respectively) compared with patients without PCR. The refractive and visual outcomes in patients with PCR were significantly worse than in those without PCR (mean CDVA 0.13 ± 0.21 vs 0.05 ± 0.16 logMAR, P < .001; mean absolute biometry prediction error 1.15 ± 1.60 diopters [D] vs 0.41 ± 0.45 D, P < .001). A multivariate linear regression analysis, adjusting for potential explanatory variables, confirmed a statistically significant difference (0.04 logMAR, P < .001, and .70 D, P < .001, respectively). Patients with PCR had significantly more postoperative complications (corneal edema 0.88% vs 0.17%, adjusted odds ratio [aOR], 2.80 95% CI, 2.27-3.45, endophthalmitis 0.11% vs 0.02%, aOR, 4.40 95% CI, 2.48-7.81, uncontrolled intraocular pressure 0.55% vs 0.03%, aOR, 14.58 95% CI, 11.16-19.06, P < .001). CONCLUSIONS: Patients with PCR had significantly worse visual and refractive outcomes and more postoperative complications than patients without PCR. However, most of these patients achieved better postoperative visual acuity than that preoperatively.

Intraocular bag-in-the-lens exchange: indications, outcomes, and complications.

PURPOSE: To report the indications, outcomes, and complications regarding bag-in-the-lens (BIL) intraocular lens (IOL) exchange over a period of 13 years in a tertiary ophthalmologic center. SETTING: Department of Ophthalmology of the University Hospital of Antwerp, Belgium. DESIGN: Observational retrospective study. METHODS: Between 2003 and 2020, 12 176 patients were operated using the BIL technique. Adult patients who underwent an intraocular BIL exchange were included, and the demographics, indications, outcomes, and complications were recorded. RESULTS: 59 eyes (0.48%) of 59 patients who underwent a BIL exchange between 2007 and 2020 were included. The mean age was 61.15 ± 13.53 years. The mean time between primary surgery and IOL exchange was 25.73 ± 41.88 months. The main indication for explantation was refractive surprise mostly related to patient risk factors, for example, preoperative corneal and refractive surgery. The mean preoperative uncorrected (UDVA) and corrected (CDVA) distance visual acuity were 0.36 ± 0.24 and 0.79 ± 0.24, respectively. The postoperative 1-month UDVA and CDVA were 0.66 ± 0.28 and 0.86 ± 0.19, respectively. The improvement in UDVA was statistically significant (<0.0001). The most common intraoperative complication was damage to the anterior hyaloid in 9 eyes (15%), which did not prohibit reimplantation of a secondary BIL. CONCLUSIONS: BIL to BIL exchange was a viable and successful technique that provides good refractive results with few, manageable complications. Because of the tertiary profile of the study center with referral of complex cases, BIL was the preferred IOL in patients at risk for postoperative refractive surprise.

Risk factors for posterior capsule rupture in cataract surgery as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery.

PURPOSE: To analyze the incidence and risk factors for posterior capsule rupture (PCR) in cataract surgery. SETTING: European clinics affiliated with the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO). DESIGN: Retrospective cross-sectional register-based study. METHODS: Data were obtained from the EUREQUO. The database contains data on demographics, comorbidities, and intraoperative complications, including PCR for the study period from January 1, 2008, to December 31, 2018. Univariate and multivariate logistic regression analyses were performed to estimate the (adjusted) odds ratio (OR) and 95% confidence intervals (CIs). RESULTS: We analyzed EUREQUO registry data of 2,853,376 patients, and 31,749 (1.1%) cataract surgeries were complicated by a PCR. Data were available of 2 853 376 patients, and 31 749 (1.1%) cataract surgeries were complicated by a PCR. The PCR rate ranged from 0.60% to 1.65% throughout the years, with a decreasing trend (P < .001). The mean age of the PCR cohort was 74.8 ± 10.5 years, and 17 29 (55.5%) patients were female. Risk factors most significantly associated with PCR were corneal opacities (OR 3.21, 95% CI, 3.02-3.41, P < .001), diabetic retinopathy (OR 2.74, 95% CI, 2.59-2.90, P < .001), poor preoperative visual acuity (OR 1.98, 95% CI, 1.88-2.07, P < .001), and white cataract (OR 1.87, 95% CI, 1.72-2.03, P < .001). CONCLUSIONS: Risk factors for PCR were identified based on the EUREQUO, and the incidence of this complication is decreasing over time.

Outcomes of Human Leukocyte Antigen-Matched Allogeneic Cultivated Limbal Epithelial Transplantation in Aniridia-Associated Keratopathy-A Single-Center Retrospective Analysis.

PURPOSE: To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivated limbal epithelial stem cell grafts in the treatment of aniridia-associated keratopathy (AAK). METHODS: Six eyes of 6 patients with severe AAK received an allogeneic stem cell graft between January 2010 and March 2017. Anatomical and functional results were assessed at 6 months, 1 year, 2 years, and the final follow-up visit available. Safety analysis was performed by considering all perioperative and postoperative adverse events and additional surgeries required during the follow-up period. RESULTS: The mean follow-up was 53.6 months (range 24-104 months). In most patients (80%), there was an early improvement of the keratopathy postoperatively, which slowly regressed during longer follow-up. At the final follow-up, 4 of the eyes were graded as failure and 1 eye was graded as partial success. Grading the sixth eye was not possible because of an adverse event. None of the patients maintained a total anatomical success in the long-term. Only 1 patient maintained a modest improvement in best-corrected visual acuity from hand motion to counting fingers. Four serious adverse events were recorded in 2 patients. CONCLUSIONS: Severe AAK remains a challenging condition to manage. Transplantation of allogenic ex vivo cultivated limbal stem cells may provide a temporary improvement in ocular surface stability, but anatomical and functional results are poor in the long-term. The eyes are prone to adverse events, and any surgical treatment should take this into consideration.

Evaluation of the vitreolenticular interface with intraoperative OCT.

PURPOSE: To determine the prevalence of anterior vitreous detachment (AVD) in routine bag-in-the-lens (BIL) cataract cases and possibly to identify risk factors for its presence. SETTING: University Hospital of Antwerp, Belgium. DESIGN: Prospective cross-sectional study. METHODS: Patients having routine BIL cataract surgery were included. Patients with traumatic cataract, previous intraocular surgeries, YAG laser treatment, intravitreal injection, or medical conditions that might affect normal ophthalmologic anatomy were excluded. Several parameters were collected from the patients' records, and their surgical videos/photographs/optical coherence tomography were evaluated. RESULTS: 99 eyes of 99 patients were included. Detectable AVD was observed in 62 eyes (63%). AVD was not present in 37 eyes (37%). The difference in prevalence of AVD between men and women was not statistically significant ( P = .55, Pearson χ 2 test). The Mann-Whitney U test for axial length was not statistically significant ( P = .38). However, it was statistically significant for age ( P < .005). A logistic regression model to ascertain the effect of age on the likelihood that patients had AVD did reach statistical significance (χ 2 (1) = 8.246, P < .005). CONCLUSIONS: The prevalence of AVD in a routine cataract population was 63%. Age was identified as a risk factor. This study model determined that the odds for AVD increase 5.3% with each year of patient age. These data allowed for better preoperative and postoperative assessment of complications. The BIL, by its mandatory primary posterior continuous curvilinear capsulorhexis, did not increase the risk for postoperative ocular complications in the posterior segment of the eye.

The importance of the epithelial fibre cell interface to lens regeneration in an in vivo rat model and in a human bag-in-the-lens (BiL) sample.

Human lens regeneration and the Bag-in-the-Lens (BIL) surgical treatment for cataract both depend upon lens capsule closure for their success. Our studies suggest that the first three days after surgery are critical to their long-term outcomes. Using a rat model of lens regeneration, we evidenced lens epithelial cell (LEC) proliferation increased some 50 fold in the first day before rapidly declining to rates observed in the germinative zone of the contra-lateral, un-operated lens. Cell multi-layering at the lens equator occurred on days 1 and 2, but then reorganised into two discrete layers by day 3. E- and N-cadherin expression preceded cell polarity being re-established during the first week. Aquaporin 0 (AQP0) was first detected in the elongated cells at the lens equator at day 7. Cells at the capsulotomy site, however, behaved very differently expressing the epithelial mesenchymal transition (EMT) markers fibronectin and alpha-smooth muscle actin (SMA) from day 3 onwards. The physical interaction between the apical surfaces of the anterior and posterior LECs from day 3 after surgery preceded cell elongation. In the human BIL sample fibre cell formation was confirmed by both histological and proteome analyses, but the cellular response is less ordered and variable culminating in Soemmerring's ring (SR) formation and sometimes Elschnig's pearls. This we evidence for lenses from a single patient. No bow region or recognisable epithelial-fibre cell interface (EFI) was evident and consequently the fibre cells were disorganised. We conclude that lens cells require spatial and cellular cues to initiate, sustain and produce an optically functional tissue in addition to capsule integrity and the EFI.

Adapted Bag-in-the-Lens Implantation Technique in Children with Congenital Ectopia Lentis.

BACKGROUND: Subluxation of the crystalline lens in childhood confronts the surgeon with a dilemma: to operate or to wait and see. Surgery is usually not performed when the subluxation is still limited. However, postponing the surgery increases the surgical difficulty as the capsular bag becomes more difficult to use as a means of support for the intraocular lens (IOL). A large number of children already present a pronounced subluxation at first presentation. In this paper, we describe a technique to optimise centration and fixation of the bag-in-the-lens (BIL) IOL in children younger than 7 years of age with congenital ectopia lentis. METHODS: Between October 2019 and December 2020, we performed lens extraction using a combination of bean-shaped segments to support the BIL IOL and a 6 - 0 polypropylene loop fixated at the sclera, following the Yamane technique, for the purpose of centration. We used this technique for seven eyes of four patients. The patients were between 2 and 6 years old; 3 boys and 1 girl. A definite diagnosis of Marfan syndrome was made for two children; for the other two, there was no proven underlying pathology. The luxation was upwards in all cases. The degree of luxation was severe in all eyes. The preoperative refraction values showed high astigmatism values for all eyes, ranging from 6.5 to 11.25 dioptres. Three out of the four patients were myopic, ranging from - 1.5 to - 9 dioptres. RESULTS: The surgery could be performed without major complications in all eyes. Good centration was obtained, which remained stable in the postoperative period. Refraction improved with greatly diminished degrees of astigmatism (ranging from 0.25 to 3 dioptres) and myopia (spheres ranging from - 2 to + 1.75 dioptres). CONCLUSION: Our novel technique incorporated the BIL technique with the addition of bean-shaped segments and a polypropylene 6/0 suture fixated at the sclera. In this way, we were able to obtain good centration and stability of the implanted IOL, as well as a good refractive outcome in all cases.

Real-time intraoperative OCT imaging of the vitreolenticular interface during pediatric cataract surgery.

PURPOSE: To report on the use of intraoperative optical coherence tomography (OCT) imaging of the vitreolenticular interface (VLI) during pediatric cataract surgery and to determine the incidence of VLI dysgenesis and surgical difficulties. SETTING: Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium. DESIGN: Retrospective cohort study. METHODS: This study included 51 pediatric patients who underwent cataract surgery between April 2016 and December 2018. Video recordings and OCT images of the VLI were analyzed and compared. VLI dysgenesis was considered present when intraoperative OCT images demonstrated partial or total adhesions between the posterior lens capsule and the anterior hyaloid membrane. Video recordings were analyzed to describe surgical difficulties, more specifically: inability to create a calibrated primary posterior continuous curvilinear capsulorhexis (PPCCC), occurrence of vitreous prolapse, need for anterior vitrectomy, and complicated IOL implantation. RESULTS: Of the 51 patients included, VLI dysgenesis was demonstrated in 27 patients (52.9%). The incidence of VLI dysgenesis was greater in children with unilateral cataract (72.4%), and children with a posterior capsule plaque (90%). PPCCC was challenging in 20 patients. A defect of the anterior hyaloid membrane was found in 16 patients. Anterior vitrectomy or cutting vitreous strands with scissors was necessary in 10 patients. CONCLUSIONS: Intraoperative OCT images were an excellent tool to evaluate the VLI and to demonstrate the presence of VLI dysgenesis during pediatric cataract surgery. Performing a calibrated PPCCC was more challenging in the presence of VLI dysgenesis. This can subsequently expose a defect in the anterior hyaloid membrane, which may result in vitreous prolapse.