Customized hydrogel contact lenses for keratoconus incorporating correction for vertical coma aberration.

PURPOSE: To study the effects on visual performance of a novel custom hydrogel contact lens, which employs a correction for vertical coma aberration, in keratoconic eyes.
METHODS: Six subjects (8 eyes) with mild or moderate keratoconus were recruited for the study. Preliminary measurements included corneal topography, wavefront aberrometry, subjective refraction, visual acuity (VA) and 50% contrast VA. Based on the aberrometry data, customized lenses were made and fitted to the subjects. Evaluation of the on-eye performance of the lenses was carried out, including wavefront aberrometry, over-refraction, VA and 50% contrast VA. In two of the subjects, both eyes were fitted with the customized lenses, and binocular performance was evaluated.
RESULTS: Monocular visual performance with a 4 mm pupil, with the lenses worn, was improved, and reached the mean values of -0.003 (LogMar units) of 100% high contrast VA, and 0.049 (in LogMar units) of 50% contrast VA. Vertical coma aberration and total higher-order aberrations (HOAs) were reduced (naked eyes: -0.64 +/- 0.21 root mean square (rms) of vertical coma and 0.86 +/- 0.15 rms of total HOAs; with the lenses worn: -0.29 +/- 0.23 rms of vertical coma and 0.57 +/- 0.17 rms of total HOAs, all for a 4 mm pupil). Binocular VA results from two of the subjects were on average -0.040 (LogMar units) 100% high contrast acuity and -0.060 (LogMar units) 50% contrast visual acuity.
CONCLUSIONS: Customized hydrogel contact lenses implementing correction of vertical coma, have been found to improve both monocular and binocular visual performance of eyes affected with mild or moderate keratoconus.