The use of ocular anatomical measurements using a rotating Scheimpflug camera to assist in the Esclera (R) scleral contact lens fitting process

Abstract

Purpose: To test for associations between Pentacam (R) derived topography variables and to evaluate the predictive power of those variables in relation to scleral contact lens (SCL) fit. Setting: Department of Ophthalmology and Visual Sciences, Federal University of Sao Paulo, Sao Paulo-SP, Brazil. Design: Prospective observational non-randomised, non-comparative study. Methods: Forty-seven patients (63 eyes) were indicated for the use of Esclera (R) SCL. All patients underwent Scheimpflug imaging before the initial SCL evaluation. The following parameters were measured by Pentacam (R): corneal elevations, thickness, density, and anterior chamber depth (ACD). Correlations between the SCL parameters and the Pentacam measurements were analysed with Pearson's correlation coefficients. A simple linear regression model was created for each lens parameter using the most-correlated Pentacam variable. Results: In the total group, the results show correlations between the SCL parameters and the corneal astigmatism, ACD and pentacam-measured corneal height (Hm), with p < 0.001 each. In addition, an inverse correlation between the lens sagittal depth (LSD) and the anterior radii minimum was shown (p < 0.001). In the keratoconus group, the results show correlations between the SCL parameters and ACD and Hm (p < 0.001, each). An inverse correlation between the LSD and the total thickness corneal density average was also observed (p = 0.003). Conclusion: There was a positive correlation between the LSD and ACD, even as LD and ACD in the keratoconus group. Thus, these results suggest that certain Pentacam measurements can be good predictors of the most appropriate Esclera (R) lens to be fitted in keratoconus patients. (C) 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.