Development in anterior segment imaging for glaucoma

Abstract

Recent developments in anterior segment imaging enable high-resolution imaging with higher speeds than previous systems. This review will focus on advances in optical coherence tomography (OCT) imaging of the anterior segment with an emphasis on angle evaluation. Anterior segment imaging with OCT is possible with both time domain and Fourier domain devices, and with light sources of different wavelengths. Recent studies have identified new risk factors for angle closure and prediction models incorporating quantitative angle width parameters have been developed for detection of gonioscopically defined angle closure. Swept source OCT is a variation of Fourier domain OCT that allows three-dimensional imaging of the angle analogous to gonioscopy and novel quantitative parameters have been described for angle measurement with this technology. Fourier domain OCT devices have higher resolution and sampling density than time domain OCT and enable visualization of more angle structures such as the Schwalbe's line and Schlemm's canal. OCT technology is expanding our understanding of angle closure disease. Although it does not replace gonioscopy in angle evaluation, it may help us identify predictors of progression along the angle closure disease spectrum such that treatment may be better targeted.