CONTRAST SENSITIVITY AFTER LASER IN-SITU KERATOMILEUSIS

Purpose: To evaluate the effect on contrast sensitivity function of la ser in situ keratomileusis (LASIK) for the correction of myopia. Setti ng: Alicante Institute of Ophthalmology, University of Alicante,:Spain ; Methods: Fourteen eyes of 10 patients had LASIK to correct myopia ra nging from 6.00 to 19.50 diopters (D). Mean preoperative myopia was 10 .39 D +/- 3.69 (SD). Contrast sensitivity was tested preoperatively an d 1, 3, and 6 months postoperatively using the CVS-1000E contrast sens itivity unit (VectorVision). Results: Contrast sensitivity decreased 1 month postoperatively;the decrease:was significant only at the low an d intermediate spatial frequencies of 3 and 6 cycles per degree (cpd) (P =.034 and .030, respectively); Starting from the first month, there was rapid recovery of contrast sensitivity and at; the third month, n o statistically significant decrease at all spatial frequencies; Six m onths after surgery, there was an increase in contrast sensitivity val ues:at 3, 12, and 18 cpd, although : the changes were not significant. Conclusion: Although LASIK decreased contrast sensitivity values at l ow and intermediate spatial frequencies for 1 month after surgery, the se values rapidly returned to the preoperative values at 3 months. The improvement at Certain : frequencies at 6 months suggests that LASIK can:improve the quality of vision in eyes with moderate and high myopi a.