Abstract
Purpose :
Amniotic membrane (AM) transplantation has been used successfully in treatment refractory macular holes. We have previously shown that amniotic membrane has regenerative capacities in the retina. In this comparative study we investigate retinal hole closure with and without AM in a porcine model of retinal hole. Our hypothesis is that AM transplantation can close large retinal holes either by scar tissue formation or regeneration of retinal cells. The aim of this study is to evaluate the anatomical, functional, and histopathological outcomes after AM transplantation in a porcine model for retinal hole.
Methods :
Danish landrace pigs were vitrectomized in full anesthesia and a subretinal bleb was created before cutting a retinal hole using a 23G vitrector. Pigs underwent either transplantation of humane freeze-dried amniotic membrane into the subretinal space or were left untreated. No tamponade was used, but sclerotomies were sutured with 7-0 VicrylTM. Prior to surgery and two and four weeks after surgery, the eyes were examined by Optical Coherence Tomography (OCT), multifocal electroretinogram (mfERG) and fundus photographs. At the end of follow-up, the eyes were enucleated for histology.
Results :
Retinal hole closure seemed to be time dependent showing that some time passes before spontaneous closure. Furthermore, it was possible to calculate a hole closure rate. We found no spontaneous hole closure in retinal holes larger than 1350 um at 4 weeks. In the AM group all holes closed regardless of size.
Conclusions :
We present a porcine model for retinal hole. Spontaneous hole closure is not a static event but happens over time. AM transplantation acts as a “band aid” or stimulator for retinal hole closure by glial scarring.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.