Iatrogenic retinal diamond deposits: an unusual complication of using the diamond-dusted membrane scraper

Sir, Internal limiting membrane peeling (ILM) is recognised as an integral step in the success of macular hole (MH) repair.1 Needles and picks are effective in raising a membrane edge, but their sharp points can perforate the retina.2 Diamond-coated instruments (30 μm diamond particles fixed with non-toxic silicone adhesive) have been developed to facilitate cortical vitreous and ILM separation from the retina.2, 3 The diamond surface provides an abrasive edge that rubs against the retinal surface and can be effective in creating a membrane-edge that can be grasped with fine forceps. During the use of diamond-coated instruments for vitreoretinal (VR) procedures, diamond particles can be shed and deposited on the retinal surface, especially when the instruments are introduced through the sclerostomy or applied to retinal surface. We recently performed 23-guage pars plana vitrectomy with ILM peel for a stage III MH. A Tano diamond-dusted membrane scraper (DDMS™ by Synergetics Inc.) was used to help create an edge to the ILM before peeling. On 2-week postoperative review, the operation was an anatomical and functional success. However, highly refractile deposits of diamond particles were noted on the macula (see Figure 1). Two particles were visible on fundoscopy and optical coherence tomography identified an additional finer particle. The patient was asymptomatic and automated static visual field testing was normal. It is advised in the literature that particles noted during surgery should be aspirated through the extrusion needle.3 However, particles may not be appreciated during surgery and small finer particles may not be visible. Our literature search did not reveal any reports of adverse consequences of residual diamond deposits of the size used in VR surgery. The long-term sequelae of residual iatrogenic retinal diamond deposits remain unknown.