Preventive effect of dorzolamide- timolol combination on intraocular pressure hikes after intravitreal bevacizumab (Avastin) injection.

Objective: To evaluate the preventive effect of the dorzolamide-timolol fixed combination on intraocular pressure (IOP) spikes following intravitreal bevacizumab (Avastin) injection in patients with proliferative diabetic retinopathy (PDR). Study Design: Randomized Controlled Trial. Setting: Department of Ophthalmology, LRBT Tertiary Teaching Eye Hospital, Multan Road, Lahore. Period: July 2023 to December 2023. Methods: In this study we enrolled 60 cases equally divided in 2 groups: Group A (trial group) received prophylactic dorzolamide-timolol fixed combination eye drops 30 minutes before intravitreal bevacizumab injection, while Group B (control group) received no prophylaxis. Baseline IOP (T0) and post-injection IOP (T30) were measured using a Perkins applanation tonometer to know the mean IOP changes between groups. Results: There was a statistically significant difference in baseline IOP between the trial (9.08 ± 1.60 mmHg) and control (14.08 ± 2.00 mmHg) groups (p < 0.001). Post-injection IOP also remained significantly lower in the trial group (9.20 ± 1.60 mmHg) compared to the control group (15.37 ± 2.13 mmHg, p < 0.001). These findings indicate that prophylactic dorzolamide-timolol effectively prevents IOP elevation following intravitreal bevacizumab injection. Conclusion: Dorzolamide-timolol prophylaxis significantly reduces IOP spikes following intravitreal bevacizumab injection, highlighting its potential as a preventive strategy for patients at risk of ocular hypertension. Given the widespread use of anti-VEGF therapy, routine prophylactic IOP control may be beneficial, particularly for high-risk patients.