The Use of Nerve Growth Factor in Surgical Wound Healing of the Cornea

Abstract

Background: Recent studies have shown how the topical application of nerve growth factor (NGF) has led to the repair of neurotrophic corneal ulcers with recovery of corneal surface sensitivity. The biological effect of NGF, at a corneal level, is mediated by the presence of specific receptors localized on the surfaces of the corneal and conjunctival cells. Objectives: To evaluate the efficacy of NGF to promote corneal wound healing after cataract surgery. Methods: Thirty patients were divided into two groups (groups A and B) and underwent cataract surgery. After surgery patients in group A received 1 drop of NGF solution (10 µg of NGF dissolved in 50 µl of saline solution, 0.9% of sodium chloride) in the conjunctival fornix every 2 h (from 6 a.m. to 12 p.m.) for 2 weeks and then 4 times a day for another week. The patients in group B received 1 drop of hyaluronic acid 0.2% eye drops in the conjunctival fornix every 2 h for 2 weeks and then 4 times a day for another week. With optical coherence tomography (OCT) we evaluated the corneal thickness at the side of the surgical wound, the endothelial cell count and the incision line in the stroma 1, 7 and 21 days after surgery. Results: Before surgery in group A and in group B, the endothelial cell count was 2,607.4 ± 261.0 versus 2,602.0 ± 266.6 (p < 0.991), and the temporal cornea edge thickness was 639.2 ± 24.7 versus 644.4 ± 31.9 µm (p < 0.605), respectively. At 24 h after surgery, the results were: 2,523.2 ± 280.5 versus 2,528.2 ± 235.7 (p < 0.988) and 804.4 ± 29.5 versus 802.6 ± 35.0 µm (p < 0.953). After 7 days the cell count values were: 2,511.4 ± 229.8 versus 2,490.0 ± 230.4 (p < 0.361) and corneal thickness 713.6 ± 16.5 versus 771.4 ± 36.5 µm (p < 0.047). Finally, 21 days after surgery, the number of endothelial cells was 2,540.2 ± 237.3 versus 2,503.4 ± 224.5 (p < 0.382) and corneal thickness 645.2 ± 22.6 versus 704.2 ± 11.8 µm (p < 0.002). In the patients treated with NGF, on day 21, we found with OCT a complete wound healing, and the stromal incision was not visible. Conclusions: This clinical experience shows that the topical administration of NGF is effective in accelerating the healing of surgical corneal wounds.