Six-year incidence of visually significant age-related cataract: the Chennai eye disease incidence study.
BACKGROUND
The aim of this study is to report the 6-year incidence of age-related cataract in a population-based study.


METHODS
The design used is a population-based cohort study.


METHODS
A cohort of 2484 phakic subjects, aged 40 years and above at baseline, from a south Indian population was included in the study.


METHODS
Bilateral phakics with visual acuity of 6/12 or better and cataract less than N2, C2 and P2 on the Lens Opacities Classification System II at baseline were included. Subjects with glaucoma and corneal or retinal diseases were excluded. Incident visually significant cataract was defined as visual acuity of less than 6/18 with a corresponding one grade or greater change in Lens Opacities Classification System II or history of having undergone cataract surgery with evidence of pseudophakia or aphakia at the 6-year follow-up.


METHODS
Six-year incidence of visually significant cataract and associated risk factors data were collected.


RESULTS
Incident visually significant cataract at 6 years was seen in 158 subjects (6.36%, 95% CI: 5.40-7.32, phakics:pseudophakics/aphakics 70:88). Incidence was higher in the rural cohort as compared with the urban cohort (P < 0.001). Incidence increased with age and was highest in the ≥70 years age group (odds ratio (OR):31.23, 95% CI: 15.20-64.16, P < 0.001). Other associated risk factors included illiteracy (OR 1.75, 95% CI: 1.17-2.61, P = 0.007) and smoking (OR 1.77, 95% CI: 1.08-2.88, P = 0.02).


CONCLUSIONS
A significant proportion of the population developed visually significant age-related cataract at 6 years. Incident visually significant cataract was significantly greater for the rural cohort between 50 and 69 years old.
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Manish
M
Panday
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Ronnie
R
George
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.|Elite School of Optometry, Chennai, India.
Rashima
R
Asokan
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.|Elite School of Optometry, Chennai, India.
Satyamangalam
S
Ve Ramesh
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.|Elite School of Optometry, Chennai, India.
Lokapavani
L
Velumuri
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Nikhil S
NS
Choudhari
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Sachi Devi
SD
Boddupalli
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Govindan T
GT
Sunil
Glaucoma Project, Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Lingam
L
Vijaya
D000328:Adult; D000368:Aged; D000375:Aging; D002386:Cataract / Q000145:classification / Q000453:epidemiology*; D002387:Cataract Extraction; D003906:Developing Countries; D005260:Female; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D013997:Time Factors; D014505:Urban Population / Q000706:statistics & numerical data; D014792:Visual Acuity
Chennai; India; cataract; incidence