Using data from the Chennai Eye Disease Incidence Study, investigators assessed the long-term risk of cataract progression among primary angle-closure suspects (PACS) who underwent laser peripheral iridotomy (LPI).
Study design
The authors evaluated 4421 subjects 6 years after their baseline assessment for the Chennai Eye Disease Incidence Study. Cataract progression, assessed using changes in LOCS II grading, was defined as change of cataract by 2 or more grades or a history of cataract surgery.
Outcomes
Among 3205 eligible subjects, cataract progression was significantly greater in the 190 who received LPI (OR 1.7, P<0.001). Other statistically significant risk factors for cataract were age (P<0.001), female gender (P=0.01) and diabetes (P<0.001).
Subgroup analysis revealed that diabetes and female gender were significant risk factors for nuclear and cortical cataract progression, whereas LPI was a risk factor only for cortical cataract (OR 1.6, P=0.007).
Limitations
This study was performed in India, a country with a large population, limited resources and resultant high rates of vision loss due to cataracts. Thus, broader applications of these findings may be unclear.
Clinical significance
The natural history of PACS is poorly understood and treatment with LPI remains controversial. This study finds that LPIs are a significant risk factor for cataract progression, specifically cortical cataracts.
In regions where ocular surgery is more available and cataract progression is less of a concern, LPI may be a worthwhile risk for a PACS given that the procedure might prevent an acute angle-closure crisis. However, due to the lack of evidence supporting this prophylactic benefit, the authors suggest that physicians reserve LPI for only the highest risk PACS eyes, especially in large populations with limited resources.