Swept-source optical coherence tomography imaging of the cortical vitreous and the vitreoretinal interface in proliferative diabetic retinopathy: assessment of vitreoschisis, neovascularisation and the internal limiting membrane
Anomalous posterior vitreous detachment leads to shrinkage of the inner vitreous with the outer precortical vitreous cortex remaining attached to the macula and retina, resulting in vitreoschisis.1 Sebag and coworkers have reported vitreoschisis in macular disorders, and vitreoschisis has been demonstrated using ultrasonography and histopathology.2–⇓4 Swept-source OCT (SS-OCT) is a new imaging technology (Atlantis DRI-OCT-1, Topcon, Japan). We demonstrate for the first time in vivo the microstructural tomographic features of and spatial vitreoretinal relationships between vitreoschisis, retinal and optic nerve head neovascularisation, detachment of the internal limiting membrane (ILM) and traction on the neuroretina in proliferative diabetic retinopathy (PDR).

We identified four diabetic patients with PDR who were previously treated with panretinal laser photocoagulation at Manchester Royal Eye Hospital. Patients had no history of intravitreal antivascular endothelial growth factor or steroid treatment, or previous surgical intervention. All patients were phakic with no other ocular comorbidity. Patients underwent SS-OCT imaging as part of their routine ophthalmic care. The study adhered to the tenets of the Declaration of Helsinki.

SS-OCT imaging showed hyper-reflective fibrovascular neovascularisation elsewhere (NVE) complexes on the retinal surface and adherent to the ILM. Hyper-reflective neovascularisation at the optic disc (NVD) loops and complexes (figure 1A) were shown to extend along the inner aspects of the disc and peripapillary ILM surface. A split within the posterior cortical vitreous was visualised as two distinct hyper-reflective bands (figure 1A). The inner and outer posterior cortical vitreous layers produced similar reflectivity signals with a bilinear appearance on the SS-OCT scans . In another case, with greater antero-posterior vitreous separation, an anomalous split within the posterior cortical vitreous was clearly visible between the NVD and NVE anchorage points on SS-OCT. A detached macular ILM with sub-ILM haemorrhage …