An endoscopic overview of the anterior vitreous base in retinal detachment and anterior proliferative vitreoretinopathy

Abstract

Purpose: Anterior proliferative vitreoretinopathy (PVR) is an important cause of persistent or recurrent retinal detachment (RD). Endoscopy provides 360° panoramic viewing of the vitreous cavity and high-magnification viewing of the anterior vitreous base (AVB). This study describes the 'in vivo' anatomy and pathoanatomy of the AVB using an ocular endoscope in RD and anterior PVR.

Methods: An intraoperative analysis of over 2000 consecutive eyes undergoing vitrectomy for RD operated with endoscopy-assisted vitrectomy was performed. It was recorded in notes dictated during surgery and in standardized operative reports. Around 1500 surgical videotapes, with the exclusion of diabetic retinopathy and trauma, selected by reviewing the OR reports and notes were retrospectively reviewed.

Results: Seven endoscopic criteria associated with anterior PVR complicating RD are described: 'en bloc' stiff anterior vitreous retraction, ciliary detachment, seeding of the AVB by abundant pigmented and/or white granulations, anterior tissue displacement, stiff 'wrinkling' at the vitreoretinal juncture, persistent shallow ciliary/RD under perfluorocarbon liquids and traction-related retinal surface haemorrhages. Causes responsible for failure of conventional vitrectomy for RD are highlighted. Findings in case of hypotony and cyclitic membranes are described.

Conclusions: Endoscopy is a significant adjunct to our understanding of the development of anterior loop traction by obviating the two constitutive parts of the AVB, anterior and posterior, their interconnections and their respective connections to the anterior segment and to the retina. It provides a unique evaluation and thorough eradication of the anterior vitreous cortex as a scaffold for anterior PVR. It might be an adjunct to the prevention of anterior PVR.

Keywords: anterior proliferative vitreoretinopathy; anterior vitreous base; endoscopy; ocular viewing system; vitrectomy.