Patterned Corneal Collagen Crosslinking for Astigmatism: Computational Modeling Study

Overview

Journal J Cataract Refract Surg

Specialty Ophthalmology

Date 2014 Apr 29

PMID 24767795

Citations 15

Authors

Ibrahim Seven

Abhijit Sinha Roy

William J Dupps Jr

Affiliations

Soon will be listed here.

Abstract

Purpose: To test the hypothesis that spatially selective corneal stromal stiffening can alter corneal astigmatism and assess the effects of treatment orientation, pattern, and material model complexity in computational models using patient-specific geometries.

Setting: Cornea and Refractive Surgery Service, Academic Eye Institute, Cleveland, Ohio, USA.

Design: Computational modeling study.

Methods: Three-dimensional corneal geometries from 10 patients with corneal astigmatism were exported from a clinical tomography system (Pentacam). Corneoscleral finite element models of each eye were generated. Four candidate treatment patterns were simulated, and the effects of treatment orientation and magnitude of stiffening on anterior curvature and aberrations were studied. The effect of material model complexity on simulated outcomes was also assessed.

Results: Pretreatment anterior corneal astigmatism ranged from 1.22 to 3.92 diopters (D) in a series that included regular and irregular astigmatic patterns. All simulated treatment patterns oriented on the flat axis resulted in mean reductions in corneal astigmatism and depended on the pattern geometry. The linear bow-tie pattern produced a greater mean reduction in astigmatism (1.08 D ± 0.13 [SD]; range 0.74 to 1.23 D) than other patterns tested under an assumed 2-times increase in corneal stiffness, and it had a nonlinear relationship to the degree of stiffening. The mean astigmatic effect did not change significantly with a fiber- or depth-dependent model, but it did affect the coupling ratio.

Conclusions: In silico simulations based on patient-specific geometries suggest that clinically significant reductions in astigmatism are possible with patterned collagen crosslinking. Effect magnitude was dependent on patient-specific geometry, effective stiffening pattern, and treatment orientation.

Financial Disclosures: Proprietary or commercial disclosures are listed after the references.

Citing Articles

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Biomechanics of Ophthalmic Crosslinking.

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Corneal Crosslinking in Refractive Corrections.

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Optical coherence elastography by ambient pressure modulation for high-resolution strain mapping applied to patterned cross-linking.

Kling S J R Soc Interface. 2020; 17(162):20190786.

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