Thin flaps help avoid overcorrection after LASIK surgery for myopia
Session Details
Session Title: Presented Poster Session: Keratorefractive Results II
Venue: Poster Village: Pod 2
First Author: : P.Rodrigues PORTUGAL
Co Author(s): : S. Frazao S. Cruz D. Cristovao M. Marques H. Nogueira C. Ornelas
Abstract Details
Purpose:
To analyse the creation of 90μm flaps as a factor to avoid overcorrection in LASIK surgery for myopia. This allows an inferior amount of altered stroma which is seen as a possible contributor for overcorrection.
Setting:
Instituto de Oftalmologia Dr. Gama Pinto.
Methods:
Retrospective study of consecutive cases of LASIK surgery for myopia correction with comparison between eyes that reached emmetropia and over/undercorrected cases, 6 months after the surgery.
Results:
We analysed 400 eyes from 215 patients with a mean age of 32.78 years. Pre-operative spherical equivalent was -3.80D. Surgery was performed with manual microkeratome that allowed the creation of 90μm flaps and mean ablation of the stroma was 63.12μm. Surgical efficacy was 0.89. There were 6 cases (0.015%) of overcorrection higher than 0.50D (max: 1.38D). This group showed a statistically significant difference when compared with the undercorrected one, with higher ablation (67μm vs 65.7μm) and efficacy (0.96 vs 0.83).
Conclusions:
It is thought that deeper ablation may contribute to overcorrection in LASIK surgery for myopia, a situation which may become very dissatisfying for the patient. In our study, the 90μm flaps allowed for a lower amount of altered corneal tissue. That could have been a factor for having few cases of overcorrection when compared to some reports of 2%-17% of consecutive hyperopia. The overcorrection was small and allowed a good efficacy. Interestingly, this group also showed higher stromal ablation, supporting the idea that this variable may contribute for overcorrection.
Financial Disclosure:
NONE
