Alejandra Consejo1,2,3, Joséphine Behaegel2,4, Maarten Van Hoey1, D Robert Iskander3, Jos J Rozema1,2. 1. Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium. 2. Department of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium. 3. Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland. 4. Department of Ophthalmology, Brussels University Hospital, Jette, Belgium.
Abstract
PURPOSE: To identify the position and magnitude of lens compression due to short-term miniscleral contact lens wear, as well as evaluating the usefulness of scleral asymmetry as a predictor for scleral lens decentered compression. METHODS: Fourteen healthy subjects (mean ± S.D.: 29.2 ± 6.0 years) wore a highly gas-permeable spherical haptic miniscleral contact lens during a 5-h period. Corneo-scleral height Fourier profilometry was captured using an Eye Surface Profiler (www.eaglet-eye.com) before and immediately after lens removal. Scleral asymmetry, lens compression location and magnitude were processed using custom-made algorithms, both globally and for scleral quadrants. RESULTS: Miniscleral contact lenses do not set uniformly on the ocular surface, with the largest decentration seen along the horizontal meridian. The greatest flexural stress exerted by the lens on the ocular surface occurs at the point coinciding with the inner diameter landing point of the lens and not with its overall diameter. Scleral asymmetry was significantly correlated with compression location (R = 0.71, p = 0.002) and compression magnitude (R = 0.81, p < 0.001), showing its potential as compression predictor. CONCLUSION: Larger amounts of scleral asymmetry will lead to more decentration of spherical haptic scleral lenses. Objective and accurate methods, like the one presented here, could help the practitioner prevent cases of scleral blanching or discomfort due to an excessive compression by the lens.
PURPOSE: To identify the position and magnitude of lens compression due to short-term miniscleral contact lens wear, as well as evaluating the usefulness of scleral asymmetry as a predictor for scleral lens decentered compression. METHODS: Fourteen healthy subjects (mean ± S.D.: 29.2 ± 6.0 years) wore a highly gas-permeable spherical haptic miniscleral contact lens during a 5-h period. Corneo-scleral height Fourier profilometry was captured using an Eye Surface Profiler (www.eaglet-eye.com) before and immediately after lens removal. Scleral asymmetry, lens compression location and magnitude were processed using custom-made algorithms, both globally and for scleral quadrants. RESULTS: Miniscleral contact lenses do not set uniformly on the ocular surface, with the largest decentration seen along the horizontal meridian. The greatest flexural stress exerted by the lens on the ocular surface occurs at the point coinciding with the inner diameter landing point of the lens and not with its overall diameter. Scleral asymmetry was significantly correlated with compression location (R = 0.71, p = 0.002) and compression magnitude (R = 0.81, p < 0.001), showing its potential as compression predictor. CONCLUSION: Larger amounts of scleral asymmetry will lead to more decentration of spherical haptic scleral lenses. Objective and accurate methods, like the one presented here, could help the practitioner prevent cases of scleral blanching or discomfort due to an excessive compression by the lens.
Authors: Jos J Rozema; Gareth D Hastings; Marta Jiménez-García; Carina Koppen; Raymond A Applegate Journal: Ophthalmic Physiol Opt Date: 2022-09-16 Impact factor: 3.992
Authors: Alejandra Consejo; David Alonso-Caneiro; Maciej Wojtkowski; Stephen J Vincent Journal: Ophthalmic Physiol Opt Date: 2020-07-23 Impact factor: 3.117