Scheimpflug tomographical changes after cross-linking in eyes with keratoconus: 4 years follow-up
First Author: B.Alves De Souza BRAZIL
Co Author(s): A. Almeida M. Dias F. Alves L. Braga A. Pena E. Feijó
To analyze corneal tomographic changes after cross-linking in eyes with progressive keratoconus of 4 years follow-up at Ophthalmology Hospital of Anápolis.
Department of Cornea, Ophthalmology Hospital of Anápolis, Anápolis, Goiás, Brazil
This retrospective study analyzed cases of eyes with keratoconus which underwent cross-linking (CXL). The parameters included in the study were: corrected distance visual acuity (CDVA), cylindrical refraction (CYL), maximum keratometry (Kmax), corneal thickness at the thinnest point (CT-T), posterior elevation (PE), corneal asphericity (Q value), distance between the apex and the thinnest point (IT value) before and after CXL in 63 eyes. Data were performed using SPSS 23.0 (SPSS Inc., Chicago, IL, USA). P value less than 0.05 was considered to be statistically significant. In parametric data we used T-paired test and in non-parametric data we used Wilcoxon test.
There were 41 patients (63 eyes) with mean age 23.51 (10-43 years). The means before and after CXL were: CDVA from 0.44 to 0.58, CYL from 3.32 to 2.70, Kmax from 56.61 to 55.14, CT-T from 449.78 to 416.24, PE from 43.70 to 50.71, Q value from -0.91 to -0.87, IT value from 0.72 to 0.81. The CDVA of 53.96% of patients had 20/32 Snellen (0.63) or better after CXL. The analysis showed that the difference between means CDVA, CYL, Kmax, CT-T and PE were statistically significant (p less than 0.01).
The clinical analysis and the Scheimpflug tomographic parameters might be used for document keratoconus progression before and after CXL. Knowledge of changes after the corneal collagen cross-linking could enhance define the role of the CXL in decreasing progression of keratoconus.