Six-year incidence of angle-closure disease in a South Indian population: the Chennai Eye Disease Incidence Study.
OBJECTIVE
To estimate the 6-year incidence of primary angle-closure (PAC) disease among adult population aged 40 years and older from rural and urban south India.


METHODS
Population-based longitudinal study.


METHODS
A complete ophthalmologic examination, including applanation tonometry, gonioscopy, biometry, stereoscopic fundus examination, and automated perimetry was performed at both baseline and at the 6-year follow up at base hospital. Incident PAC disease was defined as the development of PAC disease during the 6-year follow-up in phakic subjects without PAC disease at baseline. Diagnosis was made using the International Society Geographical and Epidemiological Ophthalmology classification.


RESULTS
The data were analyzed for 3350 subjects (mean age, 56.4 ± 8.9 years; 1547 males, 1803 females) for a diagnosis of PAC disease at baseline and at follow-up examinations. The incidence of PAC disease was identified in 134 subjects (6-year incidence rate, 4.0%; 95% confidence interval (CI), 3.3-4.7). Among the 134 subjects, 88 subjects (2.6%, 95% CI, 2.1-3.2) were primary angle-closure suspects; 37 subjects (1.1%, 95% CI, 0.7-1.5) had primary angle closure, and 9 subjects (0.3%, 95% CI, 0.1-0.4) had primary angle-closure glaucoma. There was an inverse relationship between the incidence of PAC disease and the cataract surgery rates. Significant risk factors for PAC disease on logistic regressions were higher intraocular pressure, increased lens thickness, shorter axial length, shallow anterior chamber depth, anteriorly positioned lens, and hyperopia.


CONCLUSIONS
The average incidence of PAC disease per year was 0.7%. All biometric parameters were found to be strong predictors for the incidence of PAC disease.
Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, India. Electronic address: chennaigs@rediffmail.com.
Lingam
L
Vijaya
Rashima
R
Asokan
Manish
M
Panday
Nikhil S
NS
Choudhari
Sathyamangalam Ve
SV
Ramesh
Lokapavani
L
Velumuri
Sachi Devi
SD
Boddupalli
Govindan T
GT
Sunil
Ronnie
R
George
D000328:Adult; D000368:Aged; D001699:Biometry; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis / Q000453:epidemiology*; D006068:Gonioscopy; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007429:Intraocular Pressure; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012424:Rural Population / Q000706:statistics & numerical data; D014065:Tonometry, Ocular; D014505:Urban Population / Q000706:statistics & numerical data; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology