Six-year incidence of ocular hypertension in a South Indian population: the Chennai eye disease incidence study.
OBJECTIVE
To report the 6-year incidence and risk factors for ocular hypertension (OHT) in a population-based study in southern India.


METHODS
6 years after baseline evaluation, 56.9% subjects (participants:non-participants, 4421:3353) were re-examined at the base hospital. Incident OHT was defined as an intraocular pressure above the 97.5th centile for the population with no evidence of glaucoma in the 2852 phakic subjects, 40 years or older. Subjects with trauma, laser or incisional surgery at baseline or follow-up were excluded (total exclusions: 1569).


RESULTS
Incidence of OHT at 6 years was 62/2852 subjects (2.17% (95% CI 1.64% to 2.71%, men:women, 36:26)). Incidence was higher in the rural cohort as compared with the urban cohort (80.6% vs 19.4%, p<0.001). A higher baseline intraocular pressure (with increasing OR: 16-18 mm Hg (OR 4.0, 95% CI 2.1 to 7.9), 19-21 mm Hg (OR 11.4, 95% CI 5.7 to 22.9), 22-24 mm Hg (OR 42.6, 95% CI 11.0 to 164.8, in the urban cohort)) and increasing age (50-59 years (OR 1.9, 95% CI 1.1 to 3.3), 70 years and above (OR 3.6, 95% CI 1.2 to 10.6)) were significantly associated risk factors for incident OHT.


CONCLUSIONS
A significant proportion of this normal population converted to OHT. A higher incidence of conversion was seen in the rural population.
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 Ve
SV
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; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000453:epidemiology*; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014065:Tonometry, Ocular; D014505:Urban Population / Q000706:statistics & numerical data; D058609:Visual Field Tests
Epidemiology; Glaucoma; Intraocular pressure