Neither LASIK nor photorefractive keratectomy (PRK) cause any negative long-term effect on the corneal epithelium, according to a study in the November issue of Archives of Ophthalmology.
In this study, the authors examined 29 eyes that had received myopic LASIK or PRK. They took central endothelial photographs before surgery and at nine-year follow-up. Then, the authors compared the results to 42 normal, un-operated corneas.
At nine-year follow-up, the authors concluded that endothelial cell density decreased by just 5.3% from preoperative levels. Additionally, the authors noted that the mean annual rate of postoperative cell loss was the same as that in the normal corneas—0.6%. Finally, the authors documented no correlation between the percentage of endothelial cell loss and existing refractive error, measured ablation, or preoperative or postoperative residual bed thickness.
“Our results support the findings of numerous short-term studies that found no significant endothelial cell loss after LASIK and PRK,” says author Sanjay V. Patel, M.D., of the Mayo Clinic in Rochester, Minn. Most importantly, “the findings suggest that eye banks and surgeons can consider donor corneas that have had keratorefractive procedures for use in posterior lamellar keratoplasty.”
Patel SV, Bourne WM. Corneal endothelial cell loss 9 years after excimer laser keratorefractive surgery. Arch Ophthalmol. 2009 Nov;127(11):1423-7.