Corneal first surface optical aberrations and visual performance

PURPOSE: Wavefront analysis has demonstrated that refractive surgery-induce d corneal first surface aberrations are large, are dominated by symmetric a berrations (spherical-like aberrations), and are correlated to measures of visual performance. It is not clear whether the correlation between corneal first surface aberrations and visual performance can be generalized to oth er corneal conditions where large asymmetric aberrations (coma-like aberrat ions) may dominate the aberration structure. The purpose of the research re ported here was to determine the general utility of corneal first surface w avefront analysis in predicting visual performance. METHODS: Patients were 13 normals and 78 patients with a variety of corneal conditions including surgically removed pterygia, penetrating keratoplasty , keratoconus, radial keratotomy, laser in situ keratomileusis, and others. Video-keratographs were taken for all patients and used to calculate corne al first surface wavefront variance for 3 and 7 mm pupils. Similarly, visua l performance was quantified by measurements of contrast sensitivity and hi gh and low contrast acuities through both 3 and 7 mm pupils. RESULTS: Statistically significant correlations existed between all three m easures of visual performance and the corneal wavefront variance. All relat ionships were stronger for the 7 nun diameter-pupil condition than the 3 mm pupil. CONCLUSION: Regardless of the cause, corneas with increased wavefront varia nce showed a quantifiable decrease in visual performance that was pupil siz e dependent.