Abstract
Purpose:
The purpose of this study is to compare objectively the quality of vision assessed by double-pass imaging in low myopic and moderate myopic patients operated with PRK and FemtoLASIK.
Methods:
Prospective comparative study of patients who underwent bilateral refractive surgery. Inclusion criteria were: <40 years old myopic, preoperative cylinder <1.75D. One hundred and thirty eyes of 65 patients were included. Thirty-eight patients underwent PRK, and 27 FemtoLASIK. The optical quality of each eye was measured with the OQAS preoperatively and at 3 months postoperatively using double-pass aberrometry. The Objective Scattering Index (OSI), the Modulation Transfer Function (MTF) cut-off frequency (c/deg) and the Strehl ratio (SR) were compared at each visit. The patients were divided in: low myopic PRK group, moderate myopic PRK group, low myopic FemtoLASIK group, moderate myopic FemtoLASIK group
Results:
Preoperatively mean OSI, mean MTF cut-off frequency (c/deg) and mean SR was practically the same in the 4 groups.Three months postoperatively mean OSI was 0.51+/-0.1 in the low myopic PRK group and 0.65+/-0.1 in the moderate myopic PRK group (p=0.06). Mean Mean MTF cut-off frequency (c/deg) was 39.26+/-3.35 in the low myopic PRK group and 35.47+/-2.48 in the moderate myopic PRK group (p=0.06). Mean SR was 0.23+/-0.01 in the low myopic PRK group and 0.20+/-0.01 in the moderate myopic PRK group (p=0.04). Mean OSI was 0.75+/-0.2 in the low myopic FemtoLASIK group and 1.06+/-0.1 in the moderate myopic FemtoLASIK group (p=0.02). Mean Mean MTF cut-off frequency (c/deg) was 35.22+/-4.3 in the low myopic FemtoLASIK group and 34.13+/-3.3 in the moderate myopic FemtoLASIK group (p=0.6). Mean SR was 0.2+/-0.02 in the low myopic FemtoLASIK group and 0.18+/-0.01 in the moderate myopic FemtoLASIK group (p=0.1)
Conclusions:
The group low myopic PRK and the group low myopic FemtoLASIK seem to have a better Optical quality in the postoperative period as they have less scatter, better contrast sensitivity and a larger SR. Low myopic patients seem to have a better Optical quality after refractive surgery evaluated with double-pass aberrometry.
Keywords: 479 cornea: clinical science •
679 refractive surgery: comparative studies •
684 refractive surgery: optical quality