Researchers recently found that 6mm OCT scans of the macula were able to distinguish complete from partial posterior vitreous detachment (PVD) with good sensitivity and specificity; however, the imaging protocol missed the earliest stages of PVD in the mid-periphery.

This retrospective, cross-sectional study compared 6mm and 16.5mm scans in 157 eyes of 157 patients with diabetic retinopathy (36%), various other retinal conditions (55%) or no retinal disease (19%).

The team classified eyes as stage three partial PVD when the posterior vitreous cortex was visualized without visible attachment on 6mm scans and when the vitreous was attached at the optic nerve but separated from the macula on 16.5mm scans. On both scan types, they classified eyes as stage four when neither the premacular bursa nor the posterior vitreous cortex were visualized.

The investigators reported that the stage of PVD was identical in 6mm and 16.5mm scans in 88% of eyes. They noted that 6mm scans detected complete PVD with 95% sensitivity and 98% specificity. The researchers classified seven eyes as no PVD on 6mm scans and as partial PVD on 16.5mm scans. They added that all 16.5mm scans showed some degree of PVD.