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.