Neurotrophic keratopathy and refractive surgery

Corneal nerve function is an important consideration for the refractive surgeon. In patients without a history of neuropathy, refractive surgery can lead to destruction of corneal nerves and may predispose to keratopathy. The purpose of this review is to provide an update on the effect of refractive surgery on corneal nerve function and the potential for an increased risk of neurotrophic keratopathy development.

Recent studies have reinforced that refractive surgery can cause anatomical and functional changes in corneal nerve function. Among the most commonly performed refractive surgery procedures are Laser Assisted In-situ Keratomileusis, Photorefractive Keratectomy, and Small Incision Lenticule Extraction. Due to differences in technique, these procedures can have varying effects on corneal nerve structure. Using in vivo confocal microscopy, postrefractive patients were found to have decreased total nerve density when compared with controls in the immediate postoperative period. In some studies, patients have been shown to undergo re-innervation and regain significant amounts of nerve function. The majority of studies have found that despite decreased nerve cell density, long-term outcomes of refractive surgery patients are generally favorable. However, loss of corneal nerve function can lead to a variety of serious effects ranging from dry eye disease, corneal hypoesthesia/anesthesia, neuropathic pain, to neurotrophic keratopathy and ulceration in the rare cases.

Neurotrophic keratopathy is a rare occurrence after keratorefractive surgery and is largely due to damage to corneal nerves. Proper patient selection and counseling are essential to decrease the risk of development of this devastating complication.