Sub-Basal Nerve Fiber Changes After Small-Incision Lenticule Extraction Versus Femtosecond-LASIK: 12-Month Results
Purpose
Purpose of this study was to compare corneal subbasal nerve parameters changes after femtosecond LASIK and small-incision lenticule extraction (SMILE) in 12 month postop.
Methods
In this prospective cohort study two groups of myopic patients were selected for the investigation: 20 (40 eyes) for SMILE procedure and 20 patients (40 eyes) for Femto-LASIK. SMILE procedure was performed using the 500 kHz femtosecond laser Visumax only and Femto –LASIK procedure was performed with the same femtosecond laser and eximer laser MEL 90(Carl Zeiss Meditec). We recently examined the changes in trigeminal nerve density by studying the nerve structure under a confocal specular microscope Nidek Confoscan 4 preop and in 1 month, 3 months, 6 months, and 12 months postop.
Results
Comparing 12 months postoperative results, the mean nerve fiber length (µm) comparing Femto-LASIK group with SMILE group was 544.49±395.50 (p=0,0001) and 6001.16±4094.76 (p=0,0001) respectively, length density (µm^2) was 5756.84±4294.20 (p=0,0001) and 6001.16±4094.76 (p=0,0001) respectively, number of beadings 37.68±29.76 and 42.80±29.50 respectively. No statistically significant differences were found in beading density and Nidek turtuosity parameters.
Conclusion
Comparing the results from this two groups of patients, we were able to show that small incision lenticule extraction has the potential to preserve trigeminal nerve density better than Femto-LASIK procedure.