Background: Primary angle-closure glaucoma has been reported with higher prevalence in Asian populations. There is no significant data of different response of topical medication between angle- closure and open angle eyes.
Objective: The present study investigates ocular hypotensive effect and systemic side effects of 0.1% timolol eye gel once daily compared with 0.5% timolol eye drop twice daily in patients with chronic angle-closure glaucoma.
Material and Method: The present study was a prospective, randomized, investigator-masked, two-period crossover study in chronic angle-closure glaucoma patients with each drug tested for a six week period.
Results: Twenty five eyes were included. Timolol 0.1% eye gel and 0.5% timolol eye drop significantly reduced IOP at 9 am, 11 am and 3 pm compared with baseline (p < 0.001). At week 6, the mean IOP reduction from baseline of 0.5% timolol eye drop group was higher than that of 0.1% timolol eye gel group at 9 am (3.68 mmHg, 2.51 mmHg respectively) and at 11 am (4.21 mmHg, 2.51 mmHg respectively). These differences were not statistically significant (p = 0.421, p = 0.157 respectively). At 3 pm of week 6, the mean IOP change from baseline of 0.1% timolol eye gel group (3.03 mmHg) was more than that of 0.5% timolol eye drop group (2.84 mmHg). There was also statistically insignificant difference (p = 0.873). The highest IOP reduction of 0.5% timolol eye drop was 4.21 mmHg (19.82%) at 11 am of week 6 and that of 0.1% timolol eye gel was 3.03 mmHg (14.38%) at 3 pm of the same week. There was no significant ocular side effect. Systolic blood pressure after treatment with 0.1% timolol eye gel and diastolic blood pressure after treatment with 0.5% timolol eye drop were significantly decreased from baseline (p = 0.006 and p = 0.026 respectively). But there was no clinical significance.
Conclusion: Timolol 0.5% eye drop and 0.1% timolol eye gel effectively reduced IOP in chronic angle-closure glaucoma patients. There was no statistically significant difference in the ocular hypotensive effect of both drugs over a 24-hour period. There was no ocular side effect. Systemic side effect was clinically insignificant difference in both groups.

Keywords: Timolol eye drop, Timolol eye gel, Chronic angle-closure glaucoma