Anterior segment optical coherence tomography angiography to evaluate the peripheral fitting of scleral contact lenses

Abstract

Purpose: The aim of this study was to show the potential applicability of optical coherence tomography angiography (OCTA) for the evaluation of the peripheral fitting of fully scleral contact lenses. Methods: A pilot study was proposed fitting three different scleral contact lenses (Irregular Corneal Design [ICD]) with different sagittal heights (4200, 4800, and 5600 mm) in a healthy volunteer of 27 years old. We evaluated by means of optical coherence tomography (OCT, DRI Triton) the apical clearance achieved with each of the three lenses fitted. The impact over scleral flow was assessed with the OCTA module of the same device. Results: The apical clearance was 310, 901, and 1680 µm with the scleral lenses of sagittal heights 4200, 4800, and 5600 µm, respectively. With OCTA, we evaluated the impact of the lens bearing on the conjunctival vascular flow, observing an area of vascular interruption of 0, 25, and 75% with the lenses of 4200, 4800, and 5600 µm of sagittal heights, respectively. The vascular interruption was induced in the perilimbar area, suggesting the need of readjusting the limbal clearance zone of the lens. Conclusion: Fully scleral contact lens fitting may be optimized with the use of OCTA, allowing the practitioner to perform the fitting with better control of the peripheral bearing of the lens on the conjunctival tissue, assessing the impact on vascular structures. This potential use of OCTA must be investigated further in future studies including large samples of eyes.