Sensibilidade Corneana Nos Diferentes Estadios De Queratocone: Um Estudo Piloto

Resumo

INTRODUCTION: Keratoconus is a progressive, non-inflammatory ectatic corneal disorder characterized by stromal thinning, irregular astigmatism, and visual impairment, with a substantial impact on quality of life. Beyond structural and biomechanical alterations, growing evidence indicates that keratoconus also involves changes in corneal innervation, such as reduced sub-basal nerve density, increased tortuosity, and stromal nerve thickening. These neural changes have been associated with reduced corneal sensitivity, and some studies suggest a correlation between sensitivity loss and disease severity. Given the critical role of corneal nerves in ocular surface homeostasis, wound healing, and tear production, assessing corneal sensitivity across different keratoconus stages may provide valuable insights into disease pathophysiology and progression.

METHODS: Keratoconus diagnosis was performed using Pentacam HR (Oculus, Germany). Corneal sensitivity was assessed using the Brill esthesiometer, a recently developed device that provides precise, reproducible, and operator-independent measurements, with improved clinical applicability compared to traditional contact-based methods. Keratoconus severity was classified according to the Amsler-Krumeich system and the ABCD grading system. Group differences in sensitivity were analyzed using the Kruskal-Wallis test, and correlations between disease stage and sensitivity were explored with Spearman's rank correlation coefficient.

RESULTS: Twenty patients were included (40% female; mean age 25.8 ± 8.1 years; range 13-43). Keratoconus stages were distributed as follows: stage I - 50%, stage II - 30%, stage III - 10% and stage IV - 10%. Median corneal sensitivity was 2.60 (IQR: 2.1). No statistically significant differences in sensitivity were found across stages (p > 0.05). The correlation between sensitivity and disease stage was weak and not significant (rho = 0.23, p = 0.32). Only one patient reported contact lens use, limiting subgroup analysis.

CONCLUSION: This study found no significant association between keratoconus severity, as classified by the Amsler-Krumeich system, and corneal sensitivity. Nonetheless, these results contribute to the ongoing investigation of neurosensory involvement in keratoconus and highlight the potential of the esthesiometer as a practical and reliable tool for evaluating corneal sensitivity.