Prevention of keratocyte loss after corneal deepithelialization in rabbits
B. A. Nassaralla, K. Szerenyi, M. N. Pinheiro, W. R. Wee, A. Nigam and P. J. McDonnell
Doheny Eye Institute, Department of Ophthalmology, University of Southern California School of Medicine, Los Angeles, USA.
PURPOSE: To determine if keratocyte loss, after removal of the corneal
epithelium, can be prevented by a collagen shield used alone or in
combination with a topically applied corneal preservation medium. METHODS:
Twenty-four New Zealand white rabbits were divided into six groups of four
rabbits each. The central 6 mm of corneal epithelium was removed from one
eye of each animal by means of a blunt spatula. Postoperatively, these eyes
were treated every 4 hours for 24 hours with the following: group 1,
balanced salt solution (BSS) drops (Akorn Inc, Metairie, La); group 2,
Optisol drops (Chiron IntraOptics, Irvine, Calif); group 3, a collagen
shield soaked in sterile BSS plus BSS drops; group 4, the same collagen
shield soaked in Optisol plus Optisol drops; group 5, a different collagen
shield soaked in sterile BSS plus BSS drops; and group 6, the same collagen
shield soaked in Optisol plus Optisol drops. The animals were killed at 24
hours after surgery, the corneas were fixed, and keratocytes within the
anterior and posterior cornea, beneath the epithelial defect, were
quantitated. Four untreated rabbits served as controls. RESULTS: Optisol
drops alone, applied every 4 hours after deepithelialization, did not
prevent keratocyte loss to a greater extent than did BSS drops alone (P =
.96). Both collagen shields soaked in sterile BSS plus BSS drops every 4
hours were associated with less keratocyte loss than were BSS or Optisol
drops alone. Both collagen shields soaked in Optisol plus Optisol drops
every 4 hours were most successful at minimizing keratocyte loss (P = .0002
and P = .001). CONCLUSION: After corneal deepithelialization, use of a
collagen shield in combination with topical application of a corneal
storage medium may minimize keratocyte loss and may thus be beneficial
after refractive surgery.
