Alteration in Corneal Spherical Aberration After Myopic LASIK Procedure
Narrative Responses:
Purpose
To find out the change in corneal spherical aberration before and one month after myopic Lasik procedure and to compare with post Lasik visual quality.
Methods
162 eyes of 81 young patients who underwent Lasik procedure were included in this study. Keratometry and spherical aberration of cornea were recorded by newer generation corneal topographer pre Lasik and one month post operative Lasik procedure. Cases were grouped according to their refractive error. Group A included eyes with refractive error upto -3.00 D. Group B included eyes with refractive error between > -3.00 D and -5.00 D. Eyes with refractive error above -5.0 D and upto -10.0 D were included in Group C. All cases were subjected to standard questionnaire and vector vision testing to determine visual quality.
Results
In Group A, mean stromal ablation done was 55.3 µm. The mean corneal spherical aberration increased upto 52.48% (from 0.242 µm to 0.386 µm) whereas corneal flattening was 4.25%. In Group B, mean stromal ablation was 76.8 µm. The mean corneal spherical aberration increased by 143.48% (from 0.190 to 0.464 µm) and flattening of cornea was 5.41%. In Group C, mean stromal ablation was 117.6 µm. The mean corneal spherical aberration increased by 254.59% (from 0.218 to 0.774 µm) and corneal flattening by 10.32%. There was no significant deterioration in visual quality.
Conclusion
The corneal spherical aberration increased in direct proportion to the stromal ablation in this preliminary series of 182 eyes. However, their visual quality was not affected adversely. This can lead to think about our concept of asphericity of whole eye.