Abstract
Purpose:
To assess the effects of vitrectomy with 360° endolaser on the human corneal sub-basal nerve plexus (SBNP) and to investigate correlations between corneal sub-basal nerve (SBN) density, corneal sensitivity, and corneal epithelial condition.
Methods:
Prospective, observational, non-randomized study. 15 eyes of 15 patients who underwent vitrectomy with 360° endolaser for retinal detachment (RD group) and 15 eyes of 15 patients who underwent vitrectomy for macular hole with no endolaser (MH group). Density of corneal sub-basal nerves, central corneal sensitivity, and corneal epithelium thickness were assessed. <br /> <br />
Results:
Compared with baselines values, the mean sub-basal nerve density (p<0.001), the mean corneal sensitivity (p<0.001), and the mean corneal epithelial thickness (p=0.006) significantly decreased 6 months after surgery in the RD group. Conversely, there were no significant differences in the mean sub-basal nerve density (p=0.34), mean corneal epithelial thickness (p=0.19), and mean corneal sensitivity (p=0.42) between pre-operative and 6-month values in the MH group. The corneal sub-basal nerve density significantly correlated with the corneal sensitivity (r2=0.47; p=0.004) and the corneal epithelial thickness (r2=0.42; p=0.006). The post-operative decrease in corneal sensitivity poorly correlated with the corneal epithelial thickness (r2=0.23; p=0.045). The post-operative decrease in corneal nerve density correlated with the laser energy delivered during surgery (r2=0.50; p=0.002).
Conclusions:
Sub-basal nerve density decreases after vitrectomy combined with 360° endolaser. Surgeons should take care of the long ciliary nerves intraoperatively and, when possible, avoid heavy confluent treatment at these sites, without compromising adequate retinopexy. When corneal anesthesia occurs, it is important to make an early diagnosis and to start promptly an appropriate treatment to minimize the risk of severe neurotrophic ulcer.