Posters

Development of a reference model for keratoconus progression prediction based on the characterisation of the course of non-surgically treated cases

Poster Details

First Author: A.Martínez-Abad SPAIN

Co Author(s):    D. Pinero   L. Bataille   E. Chorro   J. Alio           

Abstract Details

Purpose:

To evaluate and characterize the visual, refractive, topographic and aberrometric changes in a long term in keratoconus cases non-surgically treated due to the absence of clinically significant visual changes, as well as to design according to this characterization a predictive model estimating the progression rate of this corneal condition according to the baseline status.

Setting:

Vissum Corporation, Alicante, Spain

Methods:

Retrospective longitudinal study comprised by 68 non-surgically treated keratoconic eyes of 46 patients. Follow-up period for each patient was 6 years±12 months collecting the visual, refractive, topographic and aberrometric data at the beginning and at the end of the follow-up period. The longitudinal change for each clinical variable was evaluated, while abnormal changes were determined by percentile analysis. According to this, a categorization into progression and no-progression groups was performed for the different parameters evaluated, determining by means of a backward stepwise multiple linear regression analysis a relationship between baseline parameters and a new index of progression of keratoconus.

Results:

No statistically significant differences were found during the follow-up period in any parameter evaluated, except asphericity in 4.5-mm diameter corneal area (Q45mm)(increase of 0.425, p: 0.010) and spherical-like aberration (SA-like) RMS (decrease of 0.070 m, p: 0.002). Multiple linear regression analysis revealed that progression of the disease (PI) were significantly related to sphere (model coefficient (B): -4.792), steepest keratometry in the 3.0-mm central zone (K23mm) (B: 1.676) and asphericity in 8.0-mm diameter corneal area (Q80mm) (B: 17.585) in the base status (p<0.001). The coefficient of determination R2of the model was 0.429.

Conclusions:

The absence of significant changes (except in SA-like and Q45mm) during the follow-up period seem to indicate that cases from our sample were not progressing or showed a slight progression.We defined a new progression index, with around 40% of its variance being explained by baseline manifest refraction sphere, K23mm and Q80mm. Therefore, myopic eyes with higher K23mm and Q80mm values may experience a more pronounced progression in the long-term. Future studies should refine the validity of the model including a larger sample of patients and testing the model in surgical cases.

Financial Disclosure:

None