Leslie TW Wong,¹ Shamsul Azhar Shah^2
1Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, and ²Department of Community Health, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia

Aim: To determine the incidence rate and pattern of acute primary angle closure/primary angle closure glaucoma among the major ethnic groups in Sabah, Malaysia.
Methods: This was a retrospective study of 71 patients with acute primary angle closure who presented for the first time to the Eye Clinic at the Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia, from 1 January 2001 to 31 December 2005. Patients were identified from the patient registry at the clinic. Information was obtained from review of the case notes and was entered into a data collection sheet in tabulated format for analysis. Pearson’s chi-squared test and Fisher’s exact test were used to determine any association between qualitative variables. Independent t test was used to determine the statistical significance when comparing between 2 means. One-way analysis of variance was used to test for differences among 3 or more independent groups. Confidence intervals for incidence and relative risk were calculated at the 95% level. A p value of <0.05 was taken as statistically significant.
Results: The incidence rate for primary angle closure glaucoma among Kadazan people was 1.33/100,000 (95% confidence interval, 0.23-2.44) and in Chinese people was 2.71/100,000 (95% confidence interval, 0.05-5.36). The mean age of patients with primary angle closure glaucoma was 59.9 years (SD, 9.13 years). The incidence was highest among people aged 60 years or older, with an incidence rate of 17.25/100,000 per year (95% confidence interval, 5.3-29.2). Patients with acute glaucoma who lived within 30 km of the hospital were 6.9 times more likely to present within 1 week of the symptoms than those who lived further away (95% confidence interval, 1.44-33.83; p = 0.008). Peripheral iridotomy was more effective for patients who presented within 1 week (p = 0.035); patients who presented within 1 week had an 8.7-fold better chance of the condition being controlled with peripheral iridotomy alone (95% confidence interval, 1.1-73.0).
Conclusion: Both Chinese and Kadazan people have a relatively high incidence of primary angle closure. The condition is associated with older age. Delay in presentation for treatment is associated with travel distance, and reduces the likelihood of a successful peripheral iridotomy.

Key words: Continental population groups, Glaucoma, angle closure, Incidence, Malaysia

Asian J Ophthalmol. 2008;10:7-11.