Zonular instability-associated morphologic features in eyes with primary angle closure disease using the swept-source anterior segment - optical coherence tomography system.

BACKGROUND: This study aims to investigate the morphologic features of the crystalline lens in Primary Angle Closure Disease (PACD) patients with zonular instability during cataract surgery using the swept-source CASIA 2 Anterior Segment-Optical Coherence Tomography (AS-OCT) system. METHODS: A total of 398 eyes (125 PACD eyes with zonular instability, 133 PACD eyes with zonular stability, and 140 cataract patient controls) of 398 patients who underwent cataract surgery combined or not glaucoma surgery between January 2021 and January 2023 were enrolled. The crystalline lens parameters were measured by CASIA2 AS-OCT. Then, logistic regression was performed to evaluate the risk factors associated with zonular instability. RESULTS: The results revealed that PACD eyes had a more anterior lens equator position, a steeper anterior curvature of lens, shorter Axial Length (AL), shallower Anterior Chamber Distance (ACD), higher Lens Vault (LV) and thicker Lens Thickness (LT), when compared to eyes in the cataract control group. Furthermore, PACD eyes in the zonular instability group had steeper front R, front Rs and Front Rf, flatter back Rf, thicker lens anterior part thickness, higher lens anterior-to-posterior part thickness ratios, shallower ACD, and greater LV, when compared to PACD eyes with zonular stability. The logistic regression analysis, which was adjusted for age and gender, revealed that zonular instability was positively correlated with anterior part thickness, lens anterior-to-posterior part thickness ratio, and LV, but was negatively correlated with lens anterior radius and ACD. CONCLUSION: Steeper anterior curvature, increased lens anterior part thickness, higher anterior-to-posterior part thickness ratio, shallower ACD, and greater LV are the anatomic features of PACD eyes associated with zonular instability.

Association between contrast sensitivity function and structural damage in primary open-angle glaucoma.

AIMS: To evaluate the association between contrast sensitivity function (CSF) and glaucomatous structural damage in primary open-angle glaucoma (POAG). METHODS: A cross-sectional study was performed with 103 patients (103 eyes) aged 25-50 years who had POAG without any other ocular disease. CSF measurements were obtained by the quick CSF method, a novel active learning algorithm that covers 19 spatial frequencies and 128 contrast levels. The peripapillary retinal nerve fibre layer (pRNFL), macular ganglion cell complex (mGCC), radial peripapillary capillary (RPC) and macular vasculature were measured by optical coherence tomography and angiography. Correlation and regression analyses were used to assess the association of area under log CSF (AULCSF), CSF acuity and contrast sensitivities at multiple spatial frequencies with structural parameters. RESULTS: AULCSF and CSF acuity were positively associated with pRNFL thickness, RPC density, mGCC thickness and superficial macular vessel density (p<0.05). Those parameters were also significantly associated with contrast sensitivity at 1, 1.5, 3, 6, 12, 18 cycles per degree spatial frequencies (p<0.05) and, the lower the spatial frequency, the higher the correlation coefficient. RPC density (p=0.035, p=0.023) and mGCC thickness (p=0.002, p=0.011) had significant predictive value for contrast sensitivity at 1 and 1.5 cycles per degree, with adjusted R 2 of 0.346 and 0.343, respectively. CONCLUSIONS: Full spatial frequency contrast sensitivity impairment, most notably at low spatial frequencies, is a characteristic change in POAG. Contrast sensitivity is a potential functional endpoint for the measurement of glaucoma severity.

Predictors of angle widening after laser iridotomy in Chinese patients with primary angle-closure suspect using ultrasound biomicroscopy.

AIM: To assess the predictive value of baseline parameters of ultrasound biomicroscopy (UBM) for angle widening after prophylactic laser peripheral iridotomy (LPI) in patients with primary angle-closure suspect (PACS). METHODS: Angle-opening distance (AOD), trabecular iris angle (TIA), iris thickness, trabecular-ciliary process angle, and trabecular-ciliary process distance were measured using UBM performed before and two weeks after LPI. Iris convexity (IC), iris insertion, angulation, and ciliary body (CB) size and position were graded. Uni- and multivariate regression analyses were used to determine factors predicting the change in AOD (ΔAOD500, calculated as an angle width change before and after LPI) in all quadrants and in subgroup quadrants based on IC. RESULTS: In 94 eyes of 94 patients with PACS, LPI led to angle widening with increases in AOD500 and TIA (P<0.01). Multivariable regression analysis showed that IC (P<0.001), CB position (P=0.007) and iris insertion (P=0.049) were significantly predictive for ΔAOD500. All quadrants were categorized into extreme IC (27.8%), moderate IC (62.3%), and absent IC (9.9%) subgroups. The AOD500 increased by 220% and no other predictive factor was found in the extreme IC quadrants. The AOD500 increased by 55%, and baseline iris angulation was predictive for smaller changes in ΔAOD500 in the moderate IC quadrants. CONCLUSION: In PACS patients, quadrants with greater iris bowing predict substantial angle widening after LPI. Quadrants with a flatter iris, anteriorly positioned CB, and basal iris insertion are associated with less angle widening after LPI. Quadrants with iris angulation as well as a flatter iris configuration predict a smaller angle change after LPI.

Morphologic changes in the anterior chamber in patients with cortical or nuclear age-related cataract.

PURPOSE: To assess and compare the morphologic changes in the anterior segment in eyes with nuclear or cortical age-related cataract using Scheimpflug imaging. SETTING: Peking University People's Hospital, Beijing, China. DESIGN: Case-control study. METHODS: Patients with nuclear or cortical age-related cataract were recruited. The grade of nuclear opalescence or cortical opacity was assessed using the Lens Opacities Classification System III (LOCS III). A group of elderly subjects with a clear lens and normal vision served as the control group. Anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness were evaluated using Scheimpflug imaging (Pentacam). RESULTS: Two hundred sixty-nine patients (330 eyes) were recruited. Thirty eyes were enrolled for each nuclear opalescence and cortical grade. The control group comprised 30 eyes (19 subjects). In eyes with age-related cataract, lens thickness increased with an increase in cortical opacity, whereas the ACD and ACV values decreased. The ACD was inversely correlated with LOCS III grades for nuclear opalescence (r = -0.197, P = .004), nuclear color (r = -0.195, P = .005), and cortical opacity (r = -0.508, P<.005). There were significant differences in lens thickness, ACD, and ACV between nuclear color, nuclear opalescence, and cortical opacity for LOCS III grades 3, 4, and 5, respectively. CONCLUSIONS: There were significant differences in lens thickness, ACD, and ACV between nuclear and cortical age-related cataracts. The ACD decreased more in eyes with cortical cataract, suggesting that the risk for angle-closure glaucoma may be greater in cases of cortical opacity in which lens expansion is greater. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Association of c3 gene polymorphisms with neovascular age-related macular degeneration in a chinese population.

PURPOSE: The purpose of this study was to determine whether the genetic polymorphisms of complement factor 3 (C3) are associated with neovascular age-related macular degeneration (AMD) in the Chinese population. METHODS: A total of 123 unrelated Chinese Han patients with neovascular AMD and 130 control subjects were recruited. Their six single-nucleotide polymorphisms (SNPs) in the C3 gene, one in the complement factor H (CFH) gene and two in the complement factor B (CFB) gene were characterized. Their genotypes, allele frequencies, and odds ratios were analyzed. RESULTS: The G allele of the C3 IVS2 rs2250656, but not other tested C3 SNPs of rs2230205, rs10411506, rs2230199, rs339392, and rs163913, was significantly associated with a reduced risk for AMD in the Chinese population (OR 0.605, 95% CI 0.39-0.93, p = 0.023), even after adjusting for age, gender, smoking status, CFH rs1061170, CFB rs4151667, and CFB rs641153 allele status (OR 0.58, 95% CI 0.35-0.96, p = 0.033). However, the C3 haplotype of A-A-C-A-T-T was identified as a statistically significant risk factor for neovascular AMD (OR 1.41, 95% CI 1.02-1.94). Furthermore, the C allele of the CFH rs1061170, but not the CFB rs4151667 and rs641153, was significnatly associated with increased risk for AMD (OR 3.09, 95% CI 1.55-6.15, p < 0.001). CONCLUSION: The G allele of C3 IVS2 rs2250656 may be a significantly protective factor for neovascular AMD in the Chinese population. This, together with low MAF of C3 R102G, may be partially responsible for the low prevalence of AMD in the Chinese population.

Late postoperative capsular block syndrome versus liquefied after-cataract.

We report the case of a 76-year-old Chinese man who had uneventful cataract phacoemulsification and hydrophilic acrylic intraocular lens (IOL) implantation 6 years previously. He presented with decreased vision; a homogeneous milky substance was found between the posterior chamber IOL and the posterior capsule without IOL displacement or a change in the refractive status. The milky substance was aspirated from the capsular bag. Biochemical analysis showed the concentrations of proteins and Ca(++) in the milky liquid were higher than those in the aqueous humor. Protein identification by mass spectrometry indicated that the milky liquid contained a high concentration of alpha-crystallin and beta-crystallin.