Subretinal Implants: Optimization Of Surgical Technique Without Silicone Oil And Postoperative Intraocular Corrections

Abstract

Purpose: : Surgery for active subretinal implants has been well established during the last 6 years with safe and stable implantations in 21 patients with retinitis pigmentosa (RP). Surgical focus can now be on post-operative interventions to maximize visual outcome by small adjustments of implant position and on potential improvements such as omission of any endotamponade.

Methods: : 21 patients with RP underwent implantation of a subretinal active implant (Retina Implant AG, Germany). - 2 patients underwent subsequent minimal adjustment of the subretinal position to maximize the area under the macula in an attempt to optimize visual performance. - 1 patient underwent silicone oil exchange with subretinal rtPA 1 week after implantation for subretinal hemorrhage from a postoperative retinal break stemming from retinal injury by the polyimide foil. - 1 patient received only BSS as endotamponade, whereas all other patients had received silicone oil.

Results: : All interventions were performed without complications, resulting in the desired chip position and resolution of hemorrhage, respectively; the device remained completely unharmed and functional in all cases. Adjustments of position required neither oil exchange nor other intraocular maneuvers. Retinal integrity was maintained in all cases. - The patient with BSS endotamponade showed attached retina without hemorrhage throughout the postoperative course. - Grating acuity (GA) changed from 0.3 to 1 cpd and from unmeasurable to 0.3 cpd in the cases with position adjustments; GA reached 3.3. cpd in the patient with hemorrhagic episode and 0.33 in the patient without endotamponade (data in the latter only available in the first postoperative week).

Conclusions: : Postoperative interventions to adjust the subretinal implant position for optimization of visual function are feasible and can markedly improve visual function. Complications such as a subretinal hemorrhage can be successfully managed. The results in the first patient without silicone oil endotamponade show potential advantages; future evaluation will have to clarify this surgical option.

Clinical Trial: : http://www.clinicaltrials.gov NCT01024803

Keywords: retinitis • retinal degenerations: hereditary