Abstract
Purpose :
To compare the glial cell activation and wound healing response induced by covering the macular holes with a retinal auto graft or a patch of human amniotic membrane (hAM) in vitro.
Methods :
298 6.0-mm circular retinal explants were prepared from 19 freshly enucleated (≤ 24hrs) human cadaver eyes. 1.0 mm circular defects were created at the center of the explants with a trephine to mimic macular hole. Explants were covered with a 3.0 mm circular retinal autograft, or a 3.0 mm circular hAM graft (AmnioGraft®, TissueTech, FL). Retina explants were maintained in the culture medium for up to 3 days. Western blotting, PCR and immunohistochemistry for glial activation markers (GFAP, Vimentin, Osteopontin, Bone Morphogenic Protein 7, Serpin a) within 1 mm circumference of the macular holes were used to compare the wound healing response between groups. Uncovered holes were taken as control.
Results :
Covering the macular hole for 72 hours with hAM or retinal autograft increased GFAP (2.02x vs. 1.86x), vimentin (2.07x vs. 3.52x) and Serpin A (2.09x vs. 3.45x) expression significantly compared to uncovered macular holes (p>0.01). No significant change was detected in BMP7 expression with retinal autograft or hAM coverage. hAM coverage boosted up the osteopontin expression 1.61 times. Western blots revealed relatively (56%) lower Serpin a upregulation with hAM compared to retinal autograft coverage. Immunostaining revealed GFAP-stained retinal glia migrating over hAM to cover the macular hole.
Conclusions :
Covering the macular hole with hAM graft or a retinal autograft activates wound healing by upregulation of gliotic response and creating a scaffold for glia migration. Higher activation of gliosis with hAM, and the ease of obtaining it makes it a preferable patch for the treatment of failed chronic macular holes.
This is a 2020 ARVO Annual Meeting abstract.