Abstract
Purpose::
To describe the effects of topical timolol maleate on myopic regression after laser in-situ keratomielusis (LASIK).
Methods::
Timolol maleate was used twice daily in 32 eyes of 19 patients (age 29.9 ± 7.9 years) who had myopic regression and decrease of visual acuity (spherical equivalent [SEQ] of -1.00 or more). The treatment began 2-36 months after uneventful LASIK, and followed up for 10-38 months. SEQ, uncorrected visual acuity (UCVA), intraocular pressure (IOP), pre-operative pachymetry, ablation depth and number of laser pulses were recorded. The main outcome measure was the SEQ reduction during treatment with topical timolol.
Results::
The pre-operative SEQ was -9.6 ± 2.9 D (range -5.75 to -14.75) in the right eye and -9.9±2.6 (range -6.87 to -14.25) in the left eye. After 2-36 months, a residual myopia of -1.87±0.77 D (range -1 to -2.75 D) was noted in 32 eyes, and topical timolol maleate was started. After 1.78 ± 1.23 months (range 1-6 months) the SEQ was reduced to -0.94 ± 0.57 D (range 0 to -1.75 D), p<0.0001 (Wilcoxon test). The UCVA improved from 0.34 ± 0.15 to 0.63 ± 0.23 (p<0.0001, Wilcoxon test). The IOP did not change and remained stable. The reduction in SEQ correlated with the pre-operative SEQ (r=-0.48, p=0.0059), and with the post-operative SEQ before treatment was started (r=-0.69, p<0.0001). It marginally correlated with the calculated residual stromal bed (r=-0.32, p=0.072), and the pre-operative central corneal thickness (r=-0.29, p=0.09). Patients who continued the timolol use maintained a lower SEQ at the last follow up visit, compared to those who decided to discontinue the treatment (-1.00 ± 0.43 D vs. -1.59 ± 0.66 D, respectively; p=0.025, Mann-Whitney test). The time between surgery and beginning of timolol treatment did not affect the SEQ reduction.
Conclusions::
Long term treatment with topical timolol maleate reversed residual myopia and improved visual acuity after LASIK. The beneficial effect of timolol was maintained as long as the treatment continued.
Keywords: refractive surgery: complications • refractive surgery: LASIK