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Abstract #9648 Published in IGR 5-3
Prevalence of glaucoma in Thailand: a population based survey in Rom Klao District, Bangkok
Bourne RR; Sukudom P; Foster PJ; Tantisevi V; Jitapunkul S; Lee PS; Johnson GJ; Rojanapongpun PBritish Journal of Ophthalmology 2003; 87: 1069-1074
AIM: To determine the prevalence, demography, mechanism, and visual morbidity of glaucoma in urban Thai people. METHODS: Seven hundred and ninety subjects aged 50 years or more from Rom Klao district, Bangkok, were enumerated in a population-based cross-sectional study. Each subject underwent the following investigations: visual acuity, visual field testing, slit lamp examination, applanation tonometry, gonioscopy, and an optic disc examination after mydriasis. Main outcome measures included visual acuity (logMAR), visual fields, intraocular pressure (IOP), gonioscopic characteristics, vertical cup/disc ratio (VCDR), prevalence of types of glaucoma. Glaucoma was diagnosed on the basis of optic disc appearance and visual field defects. In eyes in which the optic disc could not be examined, glaucoma was diagnosed when visual acuity was <3/60 and either IOP >99.5th percentile or there was evidence of previous glaucoma surgery. RESULTS: Seven hundred and one subjects were examined (response rate 88.7%). In eyes with 'normal' suprathreshold visual fields, the mean IOP was 13.3 mmHg (97.5th percentile = 20 mmHg). The 97.5th and 99.5th percentiles of VCDR were 0.72 and 0.86, respectively. Of the 701 subjects examined in the clinic, 27 had glaucoma (3.8%, 95% CI: 2.5-5.6), 16 had primary open angle glaucoma (POAG, prevalence 2.3%, 95% CI: 1.3-3.7), six were primary angle closure glaucoma (PACG, prevalence 0.9%, 95% CI: 0.3-1.9), and five secondary glaucoma (SecG, prevalence 0.7%, 95% CI: 0.2-1.7). In the 43 unilaterally blind subjects, glaucoma was the cause in five (12%). One subject was bilaterally blind due to glaucoma (prevalence 11%, 95% CI: 0.3-61.9); 28 subjects (4%) were glaucoma suspects on the basis of optic disc appearance and six on the basis of visual fields only; 98 subjects (14%) had 'occludable angles' in one eye, 22 of whom had primary angle closure (PAC, prevalence 3.1%, 95% CI: 1.9-4.7); 14 had peripheral anterior synechiae in one eye; and eight had ocular hypertension (OHT). CONCLUSIONS: POAG accounted for 67% of all glaucoma, PACG 21%, and secondary glaucomas 12%. Glaucoma was the second most common cause of severe unilateral visual loss.
Dr. R.R. Bourne, Department of Epidemiology and International Eye Health, Institute of Ophthalmology, University College London, London, UK. rupert_bourne@hotmail.com
Classification:
1.1 Epidemiology (Part of: 1 General aspects)
1.5 Glaucomas as cause of blindness (Part of: 1 General aspects)