SD-OCT/SLO reveals unprecedented information about pathologic vitreous structure

This observational cross-sectional study explores the use of combined spectral-domain optical coherence tomography (SD-OCT) and scanning laser ophthalmoscopy (SLO) for vitreous imaging. Although this study is a bit beyond the purview of the average cataract surgery workup, its examination of the technology that can best characterize the state of the vitreous and its relationship to the retina, and its great educational illustrations should be of interest to all surgeons. The study is relevant to us mostly due to epiretinal membrane and its relationship to cataract outcomes and because the risk of retinal detachment in high myopes is affected by posterior vitreous detachment (PVD) status prior to surgery.

Ultrasound has been considered the standard imaging technique for detecting and documenting vitreous detachment. However, the higher resolution of OCT offers advantages when studying any intermediate step of this process. The recent introduction of SD-OCT allows better visualization of the hyaloid and a more detailed image of its structure than time-domain OCT. The coupling of this technology with SLO images allows true simultaneous visualization of the retinal surface and OCT images.

The study's authors scanned with SD-OCT/SLO 202 eyes (113 patients) with symptoms of posterior vitreous detachment (PVD). There was a high correlation between diagnosis of complete PVD by clinical exam versus SD-OCT/SLO (95 vs. 93 eyes). However, partial PVDs were detected more frequently by SD-OCT/SLO than by biomicroscopy exam (45 vs. 7 eyes; P < 0.0001). Ultrasound was performed on a subset of 30 eyes (15 patients), with high agreement found between ultrasound and SD-OCT/SLO for both complete and partial PVD.

The authors conclude that SD-OCT/SLO imaging allows extremely detailed analysis of the vitreoretinal interface and is particularly useful for defining focal changes and PVD.