Cataract quantification using swept-source optical coherence tomography

Abstract

Purpose: To develop and evaluate a cataract quantification method using a swept-source optical coherence tomography (SS-OCT) device (IOLMaster 700).

Setting: Hanusch Hospital, Vienna, Austria.

Design: Prospective multicenter case series.

Methods: This study included patients with cataract in at least 1 eye. Two independent examiners performed Lens Opacities Classification System II (LOCS II) grading at the slitlamp independently. Corrected distance visual acuity, contrast sensitivity, and SS-OCT measurements were also performed. In addition, the phacoemulsification energy and time were recorded. To develop an objective SS-OCT-based cataract quantification system, all SS-OCT scans were segmented and the local pixel intensity unit of the lens was analyzed using Matlab's grayscale counting. The pixel intensity unit of the lens nucleus (OCT-based cataract quantification system score) was equated to the clinician's subjective nuclear opalescence grading.

Results: The study evaluated 186 eyes (113 patients). The correlation between the independent examiners' LOCS grading was good (0.91) (P < .01). The correlation between the LOCS grading and OCT-based cataract quantification system score was 0.86 for examiner 1 and 0.76 for examiner 2 (both P < .01). In 24 patients, phacoemulsification time, power, and energy; visual acuity; and contrast sensitivity were available and included in the study. The OCT-based cataract quantification system scores correlated significantly with phacoemulsification time (0.71) and energy (0.64) (both P < .01).

Conclusions: Cataract density could be evaluated using an SS-OCT device, and the OCT-based cataract quantification system values correlated with the conventional LOCS II classification. Swept-source OCT measurements allowed quantification and documentation cataract density.