Correlation of Corneal Aberrations Produced by Pterygium and Its Size
Purpose
To investigate the corneal aberrations type produced by pterygium based on its size and invasion of the ocular surface and to determine if its size influences the aberrations severity.
Methods
descriptive, transversal and observational research. We included patients with pterygium in almost one eye. We excluded patients with ocular surface alteration, use of topical drugs and with decreased visual acuity by other pathology. Tomography study (pentacam©) was taken to determine the type of corneal aberrations. The aberrations grades were studied by Zernike analysis.We measured and classified all pterygia using García-Ruiz classification and we grouped according invasion in 3 grades and angular size in 4 grades.
Results
We study 59 eyes, 42 from women (71.2%) and 17 from men (28.8%), mean age of 50.4 years. All eyes had visual capacity better than 20/60. The angular size average was 49.92°. The 75% of the eyes had invasion grade 1 and only 7% with invasion grade 3. Oblique trefoil, cardinal trefoil, horizontal coma, vertical coma and spherical aberrations were determined. Correlation was obtained only in invasion grade 3 and spherical aberration was the most important with an average of 0.001209 +/- 0.0005452 (r2=0.74, p=0.10). No correlation was observed in any angular size grade.
Conclusion
there is a direct correlation between the pterygium size and induced astigmatism. Pterygium has a greater impact on the spherical aberration. There is no correlation between aberrations and size angular but is present in grade 3 of invasion.
Key words: corneal aberrations; pterygium; astigmatism, visual quality.