Open AccessContrast sensitivity before and after small incision lenticule extraction and femtosecond laser in situ keratomileusis
Author(s) -
Asik Pradhan,
Kishore R Pradhan,
Gauri Shankar Shrestha,
Purushottam Dhunganga,
Raju Kaiti
Publication year - 2019
Publication title -
asian journal of ophthalmology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.111
H-Index - 5
eISSN - 2452-0691
pISSN - 1560-2133
DOI - 10.35119/asjoo.v16i4.417
Subject(s) - keratomileusis , photopic vision , medicine , small incision lenticule extraction , lasik , contrast (vision) , ophthalmology , refractive surgery , mesopic vision , visual acuity , spatial frequency , optometry , cornea , optics , retinal , physics
Contrast sensitivity function after laser ablation of the cornea in refractive surgery is an important tool for measuring quality of visual function. The effect of small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK) on visual function can be compared by measuring spatial contrast sensitivity.
Purpose: This study was to compare contrast sensitivity function in patients undergoing refractive surgery for myopia at Tilganga Institute of Ophthalmology.
Methods: In a retrospective study, 15 subjects who underwent refractive surgeries comprising 9 cases of SMILE and 6 cases of FS-LASIK at Tilganga Eye Hospital were enrolled in the study. A major assessment included best corrected monocular contrast sensitivity with functional vision analyzer at spatial frequencies of 1.5, 3, 6, 12, and 18 cycles/deg in photopic condition (85 cd/m2) before, 3 months, and 1 year after the surgery. The average functional acuity contrast test scores for each spatial frequency were recorded. Differences between preoperative and postoperative contrast sensitivity at each spatial frequency were analyzed through parametric paired Student’s t-test.
Results: Contrast sensitivity of postoperative FS-LASIK and SMILE did not differ from preoperative values at a photopic level. However, at high spatial frequency (12 and 18 cycles/deg), contrast sensitivity function improved significantly (p < 0.05) in eyes after FS-LASIK. Eyes after SMILE surgery did not show any reduction in contrast sensitivity at all the spatial frequencies.
Conclusion: Under photopic conditions, the contrast sensitivity function is unaffected by SMILE or FS-LASIK.