Higher-order aberrations and their association with axial elongation in highly myopic children and adolescents

BackgroundVision-dependent mechanisms play a role in myopia progression in childhood. Thus, we investigated the distribution of ocular and corneal higher-order aberrations (HOAs) in highly myopic Chinese children and adolescents and the relationship between HOA components and 1-year axial eye growth.MethodsBaseline cycloplegic ocular and corneal HOAs, axial length (AL), spherical equivalent (SE), astigmatism and interpupillary distance (IPD) were determined for the right eyes of 458 highly myopic (SE ≤−5.0D) subjects. HOAs were compared among baseline age groups (≤12 years, 13–15 years and 16–18 years). Ninety-nine subjects completed the 1-year follow-up. Linear mixed model analyses were applied to determine the association between HOA components, other known confounding variables (age, gender, SE, astigmatism and IPD) and axial growth. A comparison with data from an early study of moderate myopia were conducted.ResultsAlmost all ocular HOAs and few corneal HOAs exhibited significant differences between different age groups (all p<0.05). After 1 year, only ocular HOA components was significantly negative associated with a longer AL, including secondary horizontal comatic aberration (p=0.019), primary spherical aberration (p<0.001) and spherical HOA (p=0.026). Comparing with the moderate myopia data, the association of comatic aberration with AL growth was only found in high myopia.ConclusionIn highly myopic children and adolescents, lower levels of annual ocular secondary horizontal comatic aberration changes, besides spherical aberrations, were associated with axial elongation. This suggests that ocular HOA plays a potential role in refractive development in high myopia.

National trends in surgical subspecialisation in ophthalmology in the USA

Background/aimsTo assess surgical patterns in ophthalmology by subspecialty in the USA.MethodsOphthalmic surgeons were categorised as comprehensive/subspecialist based on billed procedures in the 2017–2018 Medicare Provider Utilization and Payment Data. Poisson regression models assessed factors associated with physicians performing surgeries in the core domain (eg, cataract extractions) and subspecialty domain. Models were adjusted for provider gender, time since graduation, geographical region, practice setting and hospital affiliation.ResultsThere were 10 346 ophthalmic surgeons, 74.7% comprehensive and 25.3% subspecialists. Cataract extractions were performed by 6.0%, 9.9%, 21.0%, 88.1% and 95.3% of specialists in surgical retina, neuro-ophthalmology/paediatrics, oculoplastics, glaucoma and cornea, respectively. Retina specialists were more likely to perform cataract surgery if they were 20–30 or>30 years in practice (relative risk: 2.20 (95% CI: 1.17 to 4.12) and 3.74 (95% CI: 1.80 to 7.76), respectively) or in a non-metropolitan setting (3.78 (95% CI: 1.71 to 8.38)). Among oculoplastics specialists, male surgeons (2.71 (95% CI: 1.36 to 5.42)), those in practice 10–20 years or 20–30 years (1.93 (95% CI: 1.15 to 3.26) and 1.91 (95% CI: 1.11 to 3.27), respectively) and in non-metropolitan settings (3.07 (95% CI: 1.88 to 5.02)) were more likely to perform cataract surgery. Only 26 of the 2620 subspecialists performed surgeries in two or more subspecialty domains.ConclusionsThere is a trend towards surgical subspecialisation in ophthalmology in the USA whereby some surgeons focus their surgical practice on subspecialty procedures and rarely perform surgeries in the core domain.

Possible association between viral infection and poor survival of the corneal graft after penetrating keratoplasty in patients with congenital corneal opacity: a cohort study

BackgroundCongenital corneal opacity (CCO) is a rare disorder. Penetrating keratoplasty (PK) is the main surgical option for CCO, but many factors affect graft survival. Therefore, this study aimed to perform a virological examination of CCO specimens after PK to explore the relationship between virological factors and graft survival after PK.MethodsThis prospective study included consecutive patients (<6 months of age) diagnosed with CCO and treated with PK at Beijing Tongren Hospital from August 2017 to January 2018. Next-generation sequencing was used to detect viral DNA in the CCO specimens. The survival of the primary graft was analysed using the Kaplan-Meier method.ResultsOverall, 24 eyes of 24 infants were treated with PK during the study period. The mean age at surgery was 4.8±1.1 months. Epstein-Barr virus DNA was detected in two specimens, varicella-zoster virus DNA in one specimen, herpes simplex virus DNA in three specimens and cytomegalovirus DNA in one specimen. In the virus-positive group, only one (14.3%) graft remained clear during follow-up. In contrast, in the virus-negative group (n=17), 13 (76.5%) grafts were still clear at the last follow-up. The mean survival of the grafts in the virus-positive group was significantly shorter than in the virus-negative group (11.0±9.8 months vs 27.1±7.7, p<0.001).ConclusionThe presence of viral DNA in CCO specimens might be associated with poor graft survival after PK.

Relationship of macular ganglion cell complex thickness to choroidal microvasculature drop-out in primary open-angle glaucoma

Background/aimsTo investigate the rate of ganglion cell complex (GCC) thinning in primary open-angle glaucoma (POAG) patients with and without deep-layer microvasculature drop-out (MvD).MethodsPOAG patients who had at least 1.5 years of follow-up and a minimum of three visits were included from the Diagnostic Innovations in Glaucoma Study. MvD was detected at baseline by optical coherence tomography angiography (OCT-A). Area and angular circumference of MvD were evaluated on en face choroidal vessel density images and horizontal B-scans. Rates of global and hemisphere GCC thinning were compared in MvD and non-MvD eyes using linear mixed-effects models.ResultsThirty-six eyes with MvD and 37 eyes without MvD of 63 patients were followed for a mean of 3.3 years. In 30 out of 36 eyes, MvD was localised in the inferotemporal region. While mean baseline visual field mean deviation was similar between the two groups (p=0.128), global GCC thinning was significantly faster in eyes with MvD than in those without MvD (mean differences: −0.50 (95% CI −0.83 to –0.17) µm/year; p=0.003)). Presence of MvD, area and angular circumference of MvD were independently associated with a faster rate of thinning (p=0.002, p=0.031 and p=0.013, respectively).ConclusionIn POAG eyes, GCC thinning is faster in eyes with MvD. Detection of MvD in OCT-A images can assist clinicians to identify patients who are at higher risk for central macula thinning and glaucomatous progression and may require more intensive management.

Serum complement component 3, complement component 4 and complement component 1q levels predict progressive visual field loss in older women with primary angle closure glaucoma

AimTo evaluate the association between serum levels of complement component (C) 3, C4 and C1q and visual field (VF) loss in patients with primary angle closure glaucoma (PACG).MethodsIn this prospective cohort study, a total of 308 patients with PACG were included. The patients were followed up every 6 months (at least 2 years), with clinical examination and VF testing. Based on their sex and age, the subjects were stratified into male and female subgroups, and by age at <60 and ≥60 years per subgroup.ResultsOne hundred twenty-three (39.94%) patients showed glaucoma VF progression. The serum levels of C3, C4 and C1q were significantly lower (p<0.05) in the progression group compared with the non-progression group in the ≥60 years female subgroup. In female patients with age ≥60 years, (1) lower levels of baseline C3 (HR=0.98, p<0.001), C4 (HR=0.96, p=0.01) and C1q levels (HR=0.99, p=0.003) were associated with a greater risk of VF progression; (2) patients with lower C3 levels had significantly (p<0.05) higher rates of VF loss progression, similar to those with lower C4 and lower C1q levels; and (3) the generalised additive model revealed a negative correlation between baseline C3 (p<0.001), C4 (p<0.001) and C1q (p<0.001) levels with the risk of VF progression. No statistical significance was observed in the male (<60 and ≥60 years) and female (<60 years) subgroups.ConclusionDecreased C3, C4 and C1q levels at baseline were significantly associated with a greater risk of VF loss progression only in older women with PACG.

Automated histopathological evaluation of pterygium using artificial intelligence

PurposeThis study aimed to evaluate the efficacy of a new automated method for the evaluation of histopathological images of pterygium using artificial intelligence.MethodsAn in-house software for automated grading of histopathological images was developed. Histopathological images of pterygium (400 images from 40 patients) were analysed using our newly developed software. Manual grading (I–IV), labelled based on an established scoring system, served as the ground truth for training the four-grade classification models. Region of interest segmentation was performed before the classification of grades, which was achieved by the combination of expectation-maximisation and k-nearest neighbours. Fifty-five radiomic features extracted from each image were analysed with feature selection methods to examine the significant features. Five classifiers were evaluated for their ability to predict quantitative grading.ResultsAmong the classifier models applied for automated grading in this study, the bagging tree showed the best performance, with a 75.9% true positive rate (TPR) and 75.8% positive predictive value (PPV) in internal validation. In external validation, the method also demonstrated reproducibility, with an 81.3% TPR and 82.0% PPV for the average of four classification grades.ConclusionsOur newly developed automated method for quantitative grading of histopathological images of pterygium may be a reliable method for quantitative analysis of histopathological evaluation of pterygium.

Association of SIX1-SIX6 polymorphisms with peripapillary retinal nerve fibre layer thickness in children

PurposeAssociation of SIX1-SIX6 variants with peripapillary retinal nerve fibre layer (p-RNFL) thickness had been reported in adults. This study aimed to investigate these associations in children, with further explorations by spatial, age and sex stratifications.Methods2878 school children aged between 6 and 9 years were enrolled from the Hong Kong Children Eye Study. Three single-nucleotide polymorphisms (SNPs) at the SIX1-SIX6 locus were genotyped. The association of each SNP with p-RNFL thickness (including global and sectoral thickness) were evaluated using multiple linear regression.ResultsSNPs rs33912345 (p=7.7×10−4) and rs10483727 (p=0.0013) showed significant associations with temporal-inferior p-RNFL thickness. The C allele of rs33912345 was associated with a thinner temporal-inferior p-RNFL by an average of 2.44 µm, while rs10483727-T was associated with a thinner temporal-inferior p-RNFL by 2.32 µm. The association with temporal-inferior p-RNFL was the strongest in the 8–9 year-old group for rs33912345 (p=5.2×10−4) and rs10483727 (p=3.3×10−4). Both SNPs were significantly associated with temporal-inferior p-RNFL thickness in boys (p<0.0017), but not in girls (p>0.05). In contrast, rs12436579-C (β=1.66; p=0.0059), but not rs33912345-C (β=1.31; p=0.052) or rs10483727-T (β=1.19; p=0.078), was nominally associated with a thicker nasal-inferior p-RNFL.ConclusionsBoth rs33912345 and rs10483727 at SIX1-SIX6 were associated with p-RNFL thickness in children, especially at the temporal-inferior sector, with age-dependent and sex-specific effects. SNP rs12436579 was associated with nasal-inferior p-RNFL thickness. Our findings suggested a role of SIX1-SIX6 in RNFL variation during neural retina development in childhood.

Association of progressive optic disc tilt with development of retinal nerve fibre layer defect in children with large cup-to-disc ratio

Background/aimsWhereas myopic optic disc deformation has been posited as a risk factor for glaucomatous damage, longitudinal studies evaluating their association have been sparse. We investigated whether the optic nerve head (ONH)’s morphological alteration during myopia progression play any role in development of retinal nerve fibre layer defect (RNFLD) in children with a large vertical cup-to-disc ratio (vCDR).MethodsSixty-five normotensive eyes of 65 children aged under 8 years with (1) vCDR ≥0.5 but no additional signs of glaucoma and (2) who could be tracked at young adulthood (18–28 years) were included. Children’s spherical equivalent (SE), intraocular pressure, vCDR and optic disc tilt ratio were recorded. Rare events logistic regression analysis was employed to identify factors associated with RNFLD-development risk.ResultsThe study group’s mean age was 5.4±1.3 years, its average vCDR was 0.62±0.07, and the average SE was −0.3±1.4 dioptres ((D), range −3.15 to 2.75D) at the baseline. After an average follow-up of 16.1±3.0 years, the mean vCDR was 0.64±0.09, and the mean SE, −3.2±2.2D (range −7.25 to 0.00 D). Among the 65 eyes, 12 (18.5%) developed RNFLD. A greater SE change (OR=1.737, p=0.016) and a greater increase in tilt ratio (OR=2.364, p=0.002) were both significantly associated with higher RNFLD-development risk.ConclusionIn this cohort of Korean children with large vCDR, progressive optic disc tilt in the course of myopia progression was associated with higher RNFLD-development risk. This finding suggests that morphological alterations in the ONH during axial elongation might represent an underlying susceptibility to glaucomatous damage in large-vCDR children.

Changing operating room practices: the effect on postoperative endophthalmitis rates following cataract surgery

PurposeTo determine whether four new operating room (OR) protocols instituted because of COVID-19 reduced the cataract surgical postoperative endophthalmitis rate (POE).DesignRetrospective, sequential, clinical registry study.Methods85 552 sequential patients undergoing cataract surgery at the Aravind Eye Hospitals between 1 January 2020 and 25 March 2020 (56 551 in group 1) and 3 May 2020 and 31 August 2020 (29 011 in group 2). In group 1, patients were not gowned, surgical gloves were disinfected but not changed between cases, OR floors were not cleaned between every case, and multiple patients underwent preparation and surgery in the same OR. In group 2, each patient was gowned, surgical gloves were changed between each case, OR floors and counters were cleaned between patients, and only one patient at a time underwent preparation and surgery in the OR.ResultsGroup 1 was older, had slightly more females, and better preoperative vision. More eyes in group 2 underwent phacoemulsification (p=0.18). Three eyes (0.005%) in group 1 and 2 eyes (0.006%) in group 2 developed POE (p=0.77). Only one eye that underwent phacoemulsification developed POE; this was in group 1. There was no difference in posterior capsule rupture rate between the two groups.ConclusionsAdopting a set of four temporary OR protocols that are often mandatory in the Western world did not reduce the POE rate. Along with previously published studies, these results challenge the necessity of these common practices which may be needlessly costly and wasteful, arguing for the reevaluation of empiric and potentially unnecessary guidelines that govern ophthalmic surgeries.

Evaluation of retinal nerve fibre layer thickness as a possible measure of diabetic retinal neurodegeneration in the EPIC-Norfolk Eye Study

Background/aimsMarkers to clinically evaluate structural changes from diabetic retinal neurodegeneration (DRN) have not yet been established. To study the potential role of peripapillary retinal nerve fibre layer (pRNFL) thickness as a marker for DRN, we evaluated the relationship between diabetes, as well as glycaemic control irrespective of diabetes status and pRNFL thickness.MethodsLeveraging data from a population-based cohort, we used general linear mixed models (GLMMs) with a random intercept for patient and eye to assess the association between pRNFL thickness (measured using GDx) and demographic, systemic and ocular parameters after adjusting for typical scan score. GLMMs were also used to determine: (1) the relationship between: (A) glycated haemoglobin (HbA1c) irrespective of diabetes diagnosis and pRNFL thickness, (B) diabetes and pRNFL thickness and (2) which quadrants of pRNFL may be affected in participants with diabetes and in relation to HbA1c.Results7076 participants were included. After controlling for covariates, inferior pRNFL thickness was 0.94 µm lower (95% CI −1.28 µm to −0.60 µm), superior pRNFL thickness was 0.83 µm lower (95% CI −1.17 µm to −0.49 µm) and temporal pRNFL thickness was 1.33 µm higher (95% CI 0.99 µm to 1.67 µm) per unit increase in HbA1c. Nasal pRNFL thickness was not significantly associated with HbA1c (p=0.23). Similar trends were noted when diabetes was used as the predictor.ConclusionSuperior and inferior pRNFL was significantly thinner among those with higher HbA1c levels and/or diabetes, representing areas of the pRNFL that may be most affected by diabetes.