Time Course of Changes in Ocular Aberrations After Instillation of Carteolol Long-Acting Solution and Timolol Gel-Forming Solution

Abstract

To investigate the influence of 2% carteolol long-acting solution (long-acting carteolol) and 0.5% timolol gel-forming solution (timolol gel) on ocular wavefront aberrations. Ocular aberrations were assessed in the right eye of 24 healthy volunteers at baseline and at 2, 5, 10, and 15 min after instillation of long-acting carteolol, timolol gel or physiological saline using the Hartmann-Shack aberrometer. Ten serial measurements were taken over 10 s at each time point, and the root mean square (RMS) of second-, third-, fourth-, and total higher-order aberrations were calculated. The stability index and fluctuation index were also determined. Second-order aberrations did not change significantly after instillation of study eye-drops. Higher-order aberrations increased significantly after instillation of long-acting carteolol and timolol gel. Timolol gel induced significantly larger changes than long-acting carteolol in third-order RMS at 2 min (P = 0.001), fourth-order RMS at 2 (P < 0.001) and 5 (P = 0.013) min, and total higher-order RMS at 2 (P < 0.001) and 5 (P = 0.016) min after instillation, but not at 10 and 15 min after administration. Fluctuation index increased significantly after instillation of each eye-drop (P < 0.001), with significantly larger increases after timolol gel than long-acting carteolol at 2 min (P = 0.005) and 5 min (P = 0.011). No significant changes were observed in stability index. Both topical β blockers with a once-daily dosing regimen temporarily deteriorate optical quality of the eye by increasing higher-order aberrations, and the increases are much larger after instillation of timolol gel than long-acting carteolol.