Effect of Dorzolamide-Timolol fixed dose combination on central Corneal Thickness in patients of Primary Open Angle Glaucoma Versus Normal Tension Glaucoma

PURPOSE: To evaluate the effect of dorzolamide/timolol fixed dose combination on central corneal thickness in primary open-angle and normal tension glaucoma. METHOD: This retrospective cohort study was approved by the Ethical Review Board of College of Ophthalmology and Allied vision Sciences (1469/23) and was conducted at Diagnostic clinic Mayo Hospital, Lahore from March, 2023 to September, 2023. Sample size was calculated by a formula whose level of significance (????) was 5%, standard deviation (????) 30.9 and test values of population mean (µ̥) was 540. Using non-probability convenient sampling method total sample size was 80 patients of age group 30 to 60 which divided into normal tension and primary open angle glaucoma of 40 each. Patients with corneal edema, diabetes, and allergic to dorzolamide-timolol fixed dose combination were excluded. Data was analyzed using SPSS version 25.00. Wilcoxon signed ranks test and chi-square test were used for the significance of the study. Data p-value <0.005 considered significant. All the tests were performed after patient’s informed consent. Intraocular pressure (IOP) and central corneal thickness (CCT) were measured by Goldmann applanation tonometer and ultrasound Pachymeter respectively. RESULTS: IOP and CCT in right eye 16.17± 7.05 (p=0.000) and 545.50± 22.2 (p=0.098) respectively and of left eye 16.56± 7.00 (p=0.003) and 549.16± 20.0 (p=0.133) respectively. This illustrates significant difference in intraocular pressure after treatment in both eyes but insignificance difference in central corneal thickness. CONCLUSION: Dorzolamide-Timolol combination successfully reduces IOP as intended and leads to no statistically significant change in central corneal thickness.