Abstract:
Keratoplasty procedures offer a proven increase in visual performance for most keratoconic patients. However, there can often remain subtle visual decrements. The visual functions of four subjects who had undergone uniocular penetrating keratoplasty with a successful visual outcome were evaluated by measurements of visual acuity, contrast thresholds for sinusoidal gratings, and contrast thresholds in the presence of a glare source. Contrast thresholds normally showed only slight elevations compared with those of age-matched controls. However, glare-sensitised thresholds revealed substantial visual decrements. These losses are not always present, are not easily predictable, and yet can be visually debilatating.