Progression of pellucid marginal degeneration and higher-order wavefront aberration of the cornea.

PURPOSE To report the time course of changes in corneal wavefront aberrations in a patient with pellucid marginal degeneration. CASE A 59-year-old man with pellucid marginal degeneration was followed-up annually with slit-lamp microscopy and videokeratography for 11 years. The anterior corneal height data of the videokeratography were expanded into the set of orthogonal Zernike polynomials to calculate wavefront aberrations for the central 3-mm cornea. OBSERVATIONS Although the patient complained of gradual deterioration of vision, there was no evident sign of disease progression on slit-lamp examination and visual acuity measurement. Color-coded maps of videokeratography showed slight deterioration over time, but no remarkable and decisive changes were seen. Coma-like aberration displayed a gradual, but apparent increase with a 1.67-fold worsening (0.473 microm to 0.792) during the 11-year follow-up period. Spherical-like aberration remained almost stable throughout the observation period. There were no obvious changes in crystalline lens and retina. CONCLUSIONS The results suggest that increases in coma-like aberrations of the cornea reflect the subclinical progression of pellucid marginal degeneration over the years.