The Impact of Soft Contact Lenses on the Corneal Neuromediators and Optical Quality in High Myopia Prior to SMILE

Corneal neuromediators, including NGF(pg/mL), CGRP(pg/mL), SP(pg/mL), IGFBP-1(ng/mL), and MANF(pg/mL), which play pivotal roles in maintaining normal physiological functions of the cornea.

Preoperative corneal aberration measurements were performed using a Scheimpflug tomography system (Pentacam; Oculus GmbH, Wetzlar, Germany). Images of the highest quality (designated as OK) were selected for analysis. The coefficients for a standardized diameter of 8 ?mm were examined, followed by an assessment of the clinical significance of total higher-order aberrations (HOA, mm), spherical aberration (Z4, 0, mm), horizontal coma (Z3, 1, mm), vertical coma (Z3, -1, mm), horizontal trefoil (Z3, 3, mm), and oblique trefoil (Z3, -3, mm) in relation to visual quality.

The Pentacam HR was used to collect data on corneal densitometry values, which were expressed in grayscale units (GSUs), playing a crucial role in quantifying corneal clarity by monitoring transient haze-like reactions. The cornea was divided into four annular zones (0-2 mm, 2-6 mm, 6-10 mm, and 10-12 mm), each exhibiting distinct corneal densitometry values. Based on the anatomical layers of the cornea at different depths, it consists of four layers: a superficial anterior layer of 120 μm, a posterior layer located within the innermost part of the cornea measuring 60 μm; central layers calculated by subtracting thickness of the anterior and posterior layers from the total layer thickness; and a total layer. Corneal densitometry values were measured in the 0-2 mm and 2-6 mm to correspond to the corneal optical zone diameter of SMILE.