Cataract & Refractive Surgery Today
According to a paper presented this month at the 6th International Congress on Advanced Surface Ablation and SBK, keratocytes' density decreases substantially in the anterior stroma of refractive surgery patients during the first postoperative year and remains low for several years.1
William M. Bourne, MD, from the Mayo Clinic College of Medicine in Rochester, Minnesota, performed confocal microscopy on 34 eyes of 23 patients who underwent PRK or LASIK. At 7 years postoperatively, the density of keratocytes in the anterior stroma of PRK patients had dropped from 45,000 to 33,000 cells/mm², a total decrease of approximately 28%. He found a similar decrease (29%) in LASIK patients, whose keratocytes' density dropped from approximately 49,000 cells/mm² preoperatively to approximately 35,000 cells/mm² at 7 years postoperatively.
Because keratocytes secrete the collagen and proteoglycan necessary for the long-term maintenance of corneal clarity and curvature, the loss of these cells after refractive surgery may have long-term consequences for patients' corneal health, said Dr. Bourne. "We feel this possibility is unlikely, but cannot be ruled out," he added.
1. Bourne WM. The effect of PRK and LASIK on corneal keratocytes. Paper presented at: The 6th International Congress on Advanced Surface Ablation and SBK; May 5, 2007; Fort Lauderdale, FL.