ESCRS - FPS07.07 - Neuropathic Ocular Surface Changes, Corneal Nerve Imaging And Neuromediator Profiles In Smile And Femtosecond Lasik

Neuropathic Ocular Surface Changes, Corneal Nerve Imaging And Neuromediator Profiles In Smile And Femtosecond Lasik

Published 2022 - 40th Congress of the ESCRS

Reference: FPS07.07 | Type: Free paper | DOI: 10.82333/fs0b-6b63

Authors: Yu-Chi Liu* 1 , Louis Tong 1 , Jodhbir Mehta 2

1Ophthalmology,Singapore Eye Research Institute,Singapore,Singapore;Ophthalmology,Singapore National Eye Centre,Singapore,Singapore, 2Ophthalmology,Singapore National Eye Centre,Singapore,Singapore

Purpose

To evaluate, compare and correlate the neuropathic ocular surface changes, corneal nerve imaging and neuromediator profiles in SMILE and femtosecond LASIK.

 

Setting

 Singapore National Eye Centre

Methods

25 SMILE patients (n=50 eyes) and 25 LASIK (n=50 eyes) were prospectively followed up for 1 year. Five clinical neuropathic ocular surface assessments, 7 corneal nerve parameters, OSDI questionnaire, and 4 tear neuromediators, were evaluated.  

Results

SMILE, compared to LASIK, had significantly better corneal sensitivity at 1 week, 1, 3 and 6 months, better TBUT at 3 months, lower NEI and Oxfords scores at 1 week. SMILE had significantly better corneal nerve fiber length (CNFL), density (CNFD), total branch density, fiber area, fiber width (CNFW) and fiber fractal dimension (CFracDim) than LASIK throughout 1year. There were significant increase in NGF at 1 month, and decrease in substance P (SP) at 1 month in LASIK, while the changes were insignificant in SMILE. CNFL, CNFD, CNFW, CFracDim and tear SP levels were significantly associated with TBUT. Tear SP, neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP) levels were significantly correlated all the nerve parameters.

 

Conclusions

The postoperative corneal denervation was long-lasting, with faster restoration in SMILE. SMILE was also associated with less negative impact on ocular surface and less fluctuations in neuroinflammatory reaction. Even though clinical symptoms and signs have subsided, significant alterations in corneal neurobiological status and nerve metrics were still observed.