Scanning electron microscopy comparison of corneal epithelial removal techniques before photorefractive keratectomy

To evaluate and compare the most common epithelial removal techniques by scanning electron microscopy.

Beckman Laser Institute, University of California, Irvine, California, USA.

The epithelium was removed in both eyes of 5 Dutch belted rabbits by 1 of 5 techniques: blunt mechanical debridement (with a blunt spatula), sharp mechanical debridement (with a sharp scalpel blade), application of topical alcohol, and transepithelial removal with the excimer laser and with the rotary epithelial scrubber. The animals were immediately killed and corneal specimens prepared for scanning electron microscopy. The degree of corneal trauma and the completeness of epithelial cell removal with the 5 techniques were evaluated by comparing the regularity and smoothness of the resulting stromal surfaces.

Epithelial removal with alcohol, the excimer beam, and the rotary epithelial scrubber produced a smoother, more uniform anterior stromal surface than blunt and sharp mechanical debridement.

The smooth and uniform anterior stromal surface produced with the rotary epithelial scrubber, alcohol, and the laser beam may be preferable prior to photorefractive keratectomy.