INCOMPLETE REPAIR OF RETINAL STRUCTURE AFTER VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
*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.
Toshio
T
Hisatomi
Takashi
T
Tachibana
Shoji
S
Notomi
Shunji
S
Nakatake
Kohta
K
Fujiwara
Yusuke
Y
Murakami
Yasuhiro
Y
Ikeda
Shigeo
S
Yoshida
Hiroshi
H
Enaida
Toshinori
T
Murata
Taiji
T
Sakamoto
Koh-Hei
KH
Sonoda
Tatsuro
T
Ishibashi
D000818:Animals; D001485:Basement Membrane / Q000601:surgery* / Q000648:ultrastructure; D004195:Disease Models, Animal; D008252:Macaca fascicularis; D008855:Microscopy, Electron, Scanning; D009900:Optic Nerve / Q000648:ultrastructure*; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000209:etiology*; D011183:Postoperative Complications; D012164:Retinal Diseases / Q000175:diagnosis / Q000601:surgery*; D012165:Retinal Ganglion Cells / Q000648:ultrastructure; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D014821:Vitrectomy / Q000009:adverse effects*