Cataract progression after Nd:YAG laser iridotomy in primary angle-closure suspect eyes.

BACKGROUND/AIMS: Prophylactic laser peripheral iridotomy (LPI) is performed in primary angle-closure suspect (PACS) eyes to prevent acute angle-closure attacks. However, accelerated cataractogenesis is a potential risk of the procedure that may result in decreased visual acuity. We aimed to assess the long-term impact of LPI on cataract formation in Chinese PACS. METHODS: In the Zhongshan Angle Closure Prevention Trial, eligible bilateral PACS participants received LPI in one randomly selected eye, while the fellow eye remained untreated. Cataract was graded using the Lens Opacity Classification System III, and progression was defined as an increase in grade by at least two units in any category or cataract surgery. RESULTS: In total, 889 participants were randomly assigned to LPI in one eye only (mean age 59±5 years, 83% female). At 72 months, treated eyes had slightly higher average nuclear grades (p<0.001). However, there were no differences between eyes for predefined cataract progression (cumulative probability at 72 months: 21.2% in LPI vs 19.4% in control, p=0.401) or cataract surgery (1% for both). While LPI-treated eyes had a 10% higher risk of progression over 6 years (HR=1.10 (95% CI 0.88 to 1.36)), this was not statistically significant. Visual acuity at 72 months was similar in treated and untreated eyes (p=0.43). CONCLUSION: Although lenses were graded on average as slightly more opaque in laser-treated eyes, prophylactic neodymium:yttrium-aluminum-garnet LPI did not cause significant cataract progression. Our results suggest that LPI treatment of asymptomatic narrow angles does not increase the risk of developing clinically meaningful cataract worsening over time. TRIAL REGISTRATION NUMBER: ISRCTN45213099.

Darkroom prone provocative testing in primary angle closure suspects and those with open angles.

PURPOSE: To describe the results of darkroom prone provocative testing (DRPPT) in primary angle closure suspects (PACS) and to compare the findings to controls with open angles. METHODS: 889 subjects with PACS in the Zhongshan Angle Closure Prevention Trial (a randomised controlled trial to compare prophylactic laser iridotomy to no treatment in PACS) and 89 with open angles in the 5-year follow-up of Liwan Eye Study were placed in a darkroom face down for 15 min. Intraocular pressure (IOP) was measured immediately before and after DRPPT. RESULTS: PACS participants were of similar age than controls (59.3 vs 60.5), more often female (82.9% vs 58.4%) and had lower IOP (14.3 vs 15.2 mm Hg). The average IOP increases after DRPPT was 4.3±3 mm Hg in PACS and 5.2±2.8 in controls (p<0.05). 20.5% of controls and 13.9 % of those with PACS developed an IOP spike ≥8 mm Hg after DRPPT (p<0.05). Among PACS, 15.8 % of those with all four quadrants closed had an IOP elevation of ≥ 8 mm Hg as opposed to 10.0%-12.4 % with two or three closed quadrants (p<0.05). DRPPT failed to predict who would reach a clinical trial endpoint over 6-year follow-up of those with PACS. CONCLUSIONS: A modified DRPPT failed to separate PACS from those with open angle. Although the test resulted in greater IOP elevation among those PACS participants with all four quadrants closed than in those with two or three closed quadrants, it did not offer any insight into the risk of developing acute or chronic angle closure disease over 6-year follow-up.

The Association between Near Work Activities and Myopia in Children-A Systematic Review and Meta-Analysis.

Myopia has a multifactorial etiology, although environmental factors are predominant in determining its current patterns. Currently, associations between near work activities and myopia have not been consistently observed. Therefore, we performed a systematic review to quantify the effect of near work activities on myopia in children. Relevant articles published between 1989 and 2014 were identified in MEDLINE, Embase, and the Cochrane Library, and the citation lists were reviewed. Twelve cohort studies and 15 cross-sectional studies were included (25,025 children aged between 6 and 18 years). The I2 statistic was used to assess heterogeneity. Study-level data were pooled using a random-effects model or a fixed-effects model (when less than 5 studies were included). We found that more time spent on near work activities was associated with higher odds of myopia (odds ratio [OR] = 1.14; 95% confidence interval [CI] = 1.08-1.20) and that the odds of myopia increased by 2% (OR:1.02; 95% CI = 1.01-1.03) for every one diopter-hour (hr) more of near work per week. Therefore, the development of a strategy to reduce the impact of near work on myopia would be important for preventing myopia in children.