Table 2.

Age and sex specific prevalence rates of the different grades of pterygia (n = 1210)

		Prevalence rates (95% CI)
		Grade I pterygia (Transparent)	Grade II pterygia (Intermediate)	Grade III pterygia (Opaque)	Bilateral pterygia
All ages	No
Crude rate	1210	4.5 (2.9, 6.0)	2.8 (1.3, 4.4)	2.0 (0.8, 3.2)	3.7 (2.0, 5.4)
Age adjusted rate*		4.6 (3.4, 5.8)	3.1 (2.0, 4.1)	2.3 (1.4, 3.2)	4.1 (2.9, 5.3)
Age (years)
21–30	414	1.2 (0.0, 2.7)	0.1 (0.0, 2.2)	1.0 (0.0, 2.2)	1.2 (0.0, 3.0)
31–40	393	4.3 (0.4, 8.3)	2.8 (2.0, 3.6)	1.0 (0.0, 2.7)	2.5 (1.4, 3.6)
41–50	201	10.0 (3.4, 16.4)	3.9 (0.4, 7.6)	2.5 (0.0, 6.1)	7.5 (2.2, 12.7)
51 and above	202	5.9 (0.0, 12.4)	5.9 (2.2, 9.7)	5.4 (2.2, 8.7)	7.4 (3.0, 11.9)
p (trend)		<0.001	<0.001	0.001	<0.001
Sex
Male	612	4.7 (2.5, 7.0)	3.1 (2.0, 4.2)	2.0 (0.9, 3.3)	3.6 (2.0, 5.2)
Female	598	4.1 (2.2, 6.2)	2.5 (0.0, 5.2)	1.8 (0.5, 3.2)	3.8 (1.4, 6.3)
p value		0.64	0.54	0.72	0.82
Outdoors activity 10 years ago
(>5 hours/day)	575	5.9 (3.5, 8.4)	4.2 (2.4, 6.0)	2.3 (0.0, 3.8)	4.9 (2.6, 7.2)
(≤5 hours/day)	635	3.1 (1.8, 4.5)	1.6 (0.0, 3.3)	1.7 (0.0, 3.6)	2.7 (0.8, 4.6)
p value		0.02	0.009	0.51	0.047

*Standardised to Indonesia 1990 population census.