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Updated: Apr 28, 2026
Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases
Published on: June 14, 2021
Ultrastructural changes of the vitreoretinal interface during long-term follow-up after removal of the internal
Toshio Hisatomi1, Shoji Notomi1, Takashi Tachibana2
1Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Clinical Research Institute, Kyushu Medical Centre, Fukuoka, Japan.
Purpose:
To investigate long-term ultrastructural changes in the retina after internal limiting membrane (ILM) peeling through the examination of morphologic changes 3 years after vitrectomy in cynomolgus monkeys.
Design:
Laboratory investigation.
Methods:
Pars plana vitrectomy was performed, followed by ILM peeling, in 2 primate eyes. Ultrastructural changes were investigated using light microscopy and transmission and scanning electron microscopy 3 years after ILM peeling.
Results:
The remaining posterior vitreous and ILM-peeled areas were clearly recognized after the long-term follow-up. The exposed Müller cell processes were partially damaged, while regenerative spindle-shaped Müller cell processes developed, covering most of the retina. Notably, the nerve fiber layer was found to be uncovered and exposed to the vitreous space owing to misdirection of glial wound healing in some parts. In these areas, glial wound healing occurred beneath the nerve fiber layer. Although the glial cells covered the damaged areas, there was no apparent ILM regeneration in the shape of a continuous flat sheet, with the exception of accumulated deposits of basement membrane materials.
Conclusions:
Although the retinal structures were well preserved after ILM peeling, ILM peeling resulted in mild damage to the vitreoretinal interface, which was not completely restored even after 3 years. The multilinear shape of the exposed nerve fiber may explain the previously reported dissociated optic nerve fiber layer appearance. The glial cells produced basement membrane materials around their processes, although they did not restore the ILM as a flat sheet.
