To examine retinal changes after vitrectomy with internal limiting membrane (ILM) peeling, we used a cynomolgus monkey model and focused on surgical damages of ILM peeling for long observational period of 3 years.
Vitrectomy was performed followed by ILM peeling similar to clinical settings in humans. Ultrastructural changes of the retina were investigated by light, transmission, and scanning electron microscopy at 3 months and 3 years after ILM peeling.
Ultrastructural study showed that the ILM peeled area was still clearly recognized after 3 years. The Müller cell processes covered most of the retina; however, the nerve fiber layer was partly uncovered and exposed to the vitreous space. The arcuate linear nerve fiber bundles were observed as comparable with dissociated optic nerve fiber layer appearance. Small round retinal surface defects were also observed around macula, resembling the dimple sign. Forceps-related retinal thinning was also found on the edge of ILM peeling, where we started peeling with fine forceps.
The ultrastructural studies showed that most of ILM peeling area was covered with glial cells during wound healing processes. Retinal changes were found comparable with dissociated optic nerve fiber layer appearance or dimple sign, which were clinically observed with optical coherence tomography.
We examined surgical damages of internal limiting membrane peeling in a monkey model of vitrectomy for 3 years. Ultrastructural study clearly revealed the pathology of arcuate linear pattern or small round retinal surface defects comparable with dissociated optic nerve fiber layer appearance, or dimple signs, clinically observed with optical coherence tomography.
*Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan;
†Clinical Research Institute, Kyushu Medical Centre, Fukuoka, Japan;
‡Department of Ophthalmology, Saga University School of Medicine, Saga, Japan;
§Department of Ophthalmology, Shinshu University School of Medicine, Nagano, Japan; and
¶Department of Ophthalmology, Kagoshima University School of Medicine, Kagoshima, Japan.
Reprint requests: Toshio Hisatomi, MD, PhD, Department of Ophthalmology, Graduate school of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; e-mail: email@example.com
None of the authors has any financial/conflicting interests to disclose.