Ameliorative effect of PN-277 on laser-induced retinal damage.
BACKGROUND
The retinal damage induced by laser photocoagulation increases considerably by the secondary degeneration process whereby tissues adjacent to the primary lesion are destroyed. As the neuroprotective effect of immunization by PN-277 was previously demonstrated in models of retina, optic nerve, brain, and spinal cord lesions, it may be used also for reducing retinal damage induced by laser. The aim of this study was to evaluate the neuroprotective effect of immunization with PN-277 in reducing the spread of laser-induced retinal damage.


METHODS
Standard argon laser lesions were created in 36 DA pigmented rats. Seven days before exposure to laser, the rats were divided into a test group (n = 18) that was pre-immunized with intraperitoneal injection of PN-277 and control group (n = 18) treated with saline. Histological and morphometrical evaluations of the retinal lesions were preformed 3, 20, and 60 days after the injury.


RESULTS
Significant ameliorative effect was demonstrated in the retinas of the pre-immunized animals 60 days after exposure to laser. The diameter of the lesion was 356 microm as compared with 406 microm (P < 0.01), the cell density of the photoreceptor cell bodies measured in the whole lesion was 72.4% of normal as compared with 64.5% (P = 0.01), and at the center of the lesion it was 57.3% of normal as compared with 38.2% (P < 0.01) (treated and control groups, respectively).


CONCLUSIONS
Immunization with PN-277 has an ameliorative effect in neural tissue such as the retina. This type of immunization may be of clinical significance in reducing laser-induced retinal injuries in humans.
Shulman
Shiri
S
Ophthalmology Department, Sapir Medical Centre, Kfar-Sava, Israel.
Belokopytov
Mark
M
Dubinsky
Galina
G
Belkin
Michael
M
Rosner
Mordechai
M
D000818:Animals; D004195:Disease Models, Animal; D005131:Eye Injuries / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D000068717:Glatiramer Acetate; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007274:Injections, Intraperitoneal; D017075:Laser Coagulation / Q000009:adverse effects*; D054020:Lasers, Gas / Q000009:adverse effects; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D010455:Peptides / Q000627:therapeutic use*; D051381:Rats; D012160:Retina / Q000293:injuries*; D012164:Retinal Diseases / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*
D007166:Immunosuppressive Agents; D018696:Neuroprotective Agents; D010455:Peptides; D000068717:Glatiramer Acetate