Analysis of the neuronal marker protein gene product 9.5 in internal limiting membranes after indocyanine-green assisted peeling.
BACKGROUND
Indocyanine green-assisted internal limiting membrane (ILM) peeling was suspected to disrupt the innermost layer of the neural retina. We examined whether surgically excised specimens contain remnants of neuronal tissue.


METHODS
Ten patients with macular hole underwent pars plana vitrectomy and indocyanine green-assisted ILM peeling. A total of 0.1 mL of a 0.5% indocyanine green solution was applied for 15 seconds. The ILM specimens were prepared for immunohistochemistry, using a polyclonal antibody against protein gene product 9.5. Protein gene product 9.5 is a pan-neuronal marker labeling human neuronal cells. Appropriate controls to show selectivity of the antibody were performed on neuronal tissue of donor eyes. One ILM was prepared for electron microscopy.


RESULTS
A selective expression of protein gene product 9.5 was found in neuronal fibers of the retina and optic nerve of donor eyes. Only 1 of the 10 surgical ILM specimens showed a minimal focal positivity for protein gene product 9.5. No neuronal tissue was detected on the ILM by electron microscopy.


CONCLUSIONS
Focal expression of protein gene product 9.5 in only 1 of 10 surgical ILM specimens argues against a general indocyanine green-related disruption of the innermost retinal layers. However, higher concentrations of the dye, longer incubation times or different solvents than used in this study may lead to different results.
Peters
Swaantje
S
Department of Ophthalmology, University of Luebeck, Germany.
Tatar
Olcay
O
Spitzer
Martin S
MS
Szurman
Peter
P
Aisenbrey
Sabine
S
Lüke
Matthias
M
Adam
Annemarie
A
Yoeruek
Efdal
E
Grisanti
Salvatore
S
D001485:Basement Membrane / Q000378:metabolism* / Q000601:surgery / Q000648:ultrastructure; D015415:Biomarkers / Q000378:metabolism*; D004396:Coloring Agents; D005125:Eye Banks; D006801:Humans; D007208:Indocyanine Green; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D013508:Ophthalmologic Surgical Procedures; D009900:Optic Nerve / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000378:metabolism; D012167:Retinal Perforations / Q000175:diagnosis / Q000378:metabolism* / Q000601:surgery; D014019:Tissue Donors; D043222:Ubiquitin Thiolesterase / Q000378:metabolism*; D014821:Vitrectomy
D015415:Biomarkers; D004396:Coloring Agents; C482860:UCHL1 protein, human; D043222:Ubiquitin Thiolesterase; D007208:Indocyanine Green