Anterior chamber depth (ACD) is a key anatomical risk factor for primary angle closure glaucoma (PACG). We conducted a genome-wide association study (GWAS) on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size = -0.045 mm, P = 8.17 × 10(-9)). This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046). The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45 × 10(-9); 3,458 cases vs. 3,831 controls). Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions.
To study the effect of haemodialysis on intraocular pressure (IOP) of patients at the University Malaya Medical Centre, Kuala Lumpur, and the influence of anterior chamber angles, surgery, and diabetes on the change in IOP after haemodialysis.
A 61-year-old Chinese man presented with bilateral posteriorly dislocated anterior chamber intraocular lenses (AC IOLs) one year after successful vitrectomy, removal of bilateral dislocated mature cataractous lenses and AC IOLs implantation. A thorough clinical evaluation revealed habitual eye rubbing as the only possible cause.
Thirty-seven consecutive patients (41 eyes) diagnosed with primary angle closure glaucoma (PACG) attending the Glaucoma Clinic in University Malaya Medical Centre, over a period of 6 months were categorized into acute, subacute and chronic PACG from their clinical presentation. Each case was subjected to automated refraction, A-scan biometry for anterior chamber depth, axial length and lens thickness, keratometry and corneal diameter measurement. Calculations for the relative lens position and the lens thickness: axial length index were performed. The data collected was analysed by the nonparametric test (Kruskal-Wallis), one way analysis of variance (ANOVA), chi-square test, Spearman's nonparametric correlations and regression analysis. For controls 15 eyes from 15 normal subjects matched for age, sex, refractive error and race were chosen and subjected to the same examinations. Chronic PACG was the predominant subtype (53.6% of patients and 58.5% of eyes). The ocular biometric measurements of acute PACG eyes deviated most from normals in having the shallowest anterior chamber depth, shortest axial length, smallest corneal diameter, steepest corneal radius, thickest and most anteriorly situated lens, and the greatest lens thickness: axial length index. The subacute subtype was closest to normal and chronic PACG subtype fell in between in most of the biometric characteristics. These findings were not statistically significant. All PACG eyes as a group however showed statistically significant shallower anterior chamber depth (p < 0.05), and a more anterior relative lens position (p < 0.05) compared to normals.
To assess the agreement of the optical low-coherence reflectometry (OLCR) device LENSTAR LS900 with partial coherence interferometry (PCI) device IOLMaster and applanation and immersion ultrasound biometry.
PURPOSE: To evaluate changes in anterior chamber depth (ACD) and intraocular pressure (IOP) after phacoemulsification in eyes with occludable angles and compare the results with those in eyes with normal open angles.
SETTING: Eye Clinic, Ipoh General Hospital, Ipoh, Perak, Malaysia.
METHODS: Patients with nonglaucomatous eyes with open angles or with occludable angles were recruited. Ocular biometric measurements (ACD, axial length [AL], lens thickness and position) and IOP (tonometry) were performed preoperatively and 1 day and 1, 4, 9, and 12 weeks postoperatively.
RESULTS: The open-angle group and occludable-angle group each comprised 35 patients. The occludable-angle group had a shallower ACD, shorter AL, thicker and relatively anterior lens position, and higher IOP preoperatively; postoperatively, there was a significant increase in ACD and a significant reduction in IOP (PAnterior chamber deepening was inversely related to preoperative ACD in the occludable-angle group (Panterior chamber deepening and lower IOP in eyes with occludable angles, which suggests it is an option for preventing acute angle-closure attacks in eyes with occludable angles and cataract.
FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
Study site: Eye Clinic, Ipoh General Hospital, Ipoh, Perak, Malaysia.