Effects of Topical Brinzolamide/Timolol on Refractive Outcomes in Eyes with Myopic Regression after Corneal Refractive Surgeries

Background and Objectives: To investigate the effects of topical brinzolamide/timolol on the inhibition of myopic regression after laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratomileusis (LASEK). Methodology: Sixty six eyes of 66 patients with myopic regression after corneal refractive surgery were classified into two groups: LASIK and LASEK group. All patients received topical brinzolamide/timolol twice a day for 2 months since the mean postoperative 6 months. Patients had complete eye examinations including Uncorrected Distance Visual Acuities (UDVA), intraocular pressure (IOP), anterior chamber angle and depth measurement, Spherical Equivalent (SE) and astigmatism with K value. Results: The value of IOP, SE and K at 1 and 2 months after the brinzolamide/timolol treatment were significantly reduced compared to the initial examination. The initial UDVA at 1 and 2 months after the treatment was markedly improved on the both groups. The angle and depth of anterior chamber were significantly changed for 2 months, although IOP, K value and SE reduction of both groups after the treatment for 2 months was markedly reduced. There was no significant difference in the effects of brinzolamide/timolol treatment between LASIK and LASEK group. Conclusion: Corneal biomechanical strength related factors including IOP, anterior chamber angle and depth are thought to be more responsible for the myopic regression. The improvement of myopic regression with brinzolamide/timolol treatment might be a result of the backward movement of the cornea and flattening of its curvature, which is presumably restricted to early treatment periods within 1 year.