title: Is prophylactic laser peripheral iridotomy for primary angle closure suspects a risk factor for cataract progression? The Chennai Eye Disease Incidence Study.
abstract: To report the risk of cataract progression among primary angle closure suspects (PACS) 6 years after they underwent laser peripheral iridotomy (LPI).
  
  
  
  In the Chennai Eye Disease Incidence Study, 6 years after their baseline evaluation, 4421 subjects were examined again. As part of a detailed evaluation cataract was graded using the Lens Opacities Classification System II; progression was defined as change of cataract by two or more grades or history of cataract surgery in the 6-year period. Only bilaterally phakic subjects with less than N2 or C2 or P2 cataract at baseline with no history of any form of glaucoma, primary angle closure and pseudoexfoliation were included.
  
  
  
  There were 3205 eligible subjects. Of these, 190 had undergone LPI for PACS. In comparison to the study population, they were significantly older (p<0.001), female (p=0.008), urban residents (p=0.001) and patients with hypertension (p<0.001). During the intervening period, 53 subjects had undergone cataract surgery. The cataract progression rate was significantly greater (OR 1.7, 95% CI 1.3 to 2.4, p<0.001) in those who had undergone LPI. For the study population the baseline risk factors for progression of cataract were age (p<0.001), female gender (p=0.01), diabetes (p<0.001) and LPI (p<0.001). Diabetes and female gender were significant risk factors for nuclear and cortical cataract progression; LPI was a risk factor only for cortical cataract (OR 1.6, 95% CI 1.1 to 2.3, p=0.007).
  
  
  
  There was significant cataract progression in 6 years following LPI for PACS.
authors.affiliation: Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
authors.forename: Lingam
authors.initials: L
authors.lastname: Vijaya
authors.affiliation: Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.|Elite School of Optometry, Chennai, Tamil Nadu, India.|Birla Institute of Technology and Science, Pilani, Rajasthan, India.
authors.forename: Rashima
authors.initials: R
authors.lastname: Asokan
authors.affiliation: Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
authors.forename: Manish
authors.initials: M
authors.lastname: Panday
authors.affiliation: Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
authors.forename: Ronnie
authors.initials: R
authors.lastname: George
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D002386:Cataract / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000601:surgery*; D006801:Humans; D007194:India / Q000453:epidemiology; D032801:Iridectomy / Q000009:adverse effects* / Q000379:methods; D053685:Laser Therapy / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors
keywords: Diagnostic tests/Investigation; Epidemiology; Glaucoma; Lens and zonules; Public health