Impact of Bilateral Open and Closed-angle Glaucoma on Glaucoma-specific Functioning in Asians

Purpose: To evaluate the impact of bilateral primary glaucoma on glaucoma-specific functioning in Asians. Methods: Patients with bilateral primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) aged 40 years or above of Chinese ethnicity in Singapore were recruited. All underwent a comprehensive clinical assessment of glaucoma. Glaucoma was diagnosed with a standard criteria including optic disc abnormality and visual field defect. The Glaucoma Quality of Life-15, a glaucoma-specific questionnaire, was used to evaluate the impact of glaucoma, and Rasch analysis was used to validate the Glaucoma Quality of Life-15. Results: A total of 192 patients (mean +/- SD age, 65.73 +/- 17.6 y and 65.1% male) were recruited, of which 56.2% (n=108) and 43.8% (n=84) had POAG and PACG, respectively. Fifty-four (28.1%), 85 (44.3%), and 53 (27.6%) had bilateral mild glaucoma, mild glaucoma in 1 eye and moderate/severe glaucoma in the other, and bilateral moderate/severe glaucoma, respectively. In multivariate analyses, compared with patients with mild glaucoma in both eyes, those with (a) mild glaucoma in 1 eye and moderate/ severe in other; and (b) moderate/severe glaucoma in both eyes, reported significantly poorer functioning (beta-coefficient=-8.20; confidence interval, -14.36 to -2.04; P<0.05) and (beta=-21.05; confidence interval, -28.06 to -14.04; P<0.05), respectively. A similar independent association was found for POAG and PACG. These associations were also considered to be clinically significant while comparing bilateral mild glaucoma with bilateral moderate/ severe glaucoma. We however, found no significant difference for functioning and severity of glaucoma between PACG and POAG patients (P<0.05). Conclusions: Bilateral glaucoma is worse than the mild form in any eye and is significantly associated with poor glaucoma-specific functioning in this Singaporean Chinese sample. These data emphasize the need for strategies to identify patients early and prevent deterioration beyond the mild form of the condition.