Immunocytochemical study of retinal diode laser photocoagulation in the rat.
OBJECTIVE
To determine the nature of the cellular infiltrate, alterations in cell adhesion molecules, and MHC II antigen expression in the rat retina following diode laser retinal photocoagulation.


METHODS
20 normal Lister rats underwent diode laser photocoagulation of the retina. Frozen sections from eyes enucleated at 0, 1, 5, 13, and 33 days post laser were examined for T cells (R7.3), CD4 T cells (W3/25), activated CD4 T cells (OX-40), CD8 T cells (OX-8), B cells (OX-33), and macrophages (OX-42), MHC II antigen (OX-6), and E-Selectin-1, VCAM-1, and ICAM-1.


RESULTS
Retinal diode laser photocoagulation stimulated a wound healing response in the outer retina and choroid. The cellular infiltrate included macrophages and activated CD4 T cells at 13 and 33 days post laser. Glial cells in the inner plexiform and inner nuclear layers expressed MHC II antigen at 24 hours only. ICAM-1 antigen was induced in RPE cells and in Muller cells in the inner retina at all time intervals post laser and intense staining for ICAM-1 was present around intraretinal migrated cells at 13 and 33 days post laser. VCAM-1 antigen expression was induced in the choroidal vascular endothelium and RPE at 13 and 33 days after laser as was E-Selectin-1 antigen expression which was also evident focally at the external limiting membrane in association with migrated cells adjacent to the burn.


CONCLUSIONS
These results suggest that alterations in cell adhesion molecules may regulate the migration and activation of retinal pigment epithelium, macrophages and CD4 T cells at the outer blood-retinal barrier and choroid following diode laser photocoagulation of the normal Lister rat retina.
Richardson
P R
PR
University Department of Ophthalmology, Manchester University.
Boulton
M E
ME
Duvall-Young
J
J
McLeod
D
D
D000818:Animals; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D007150:Immunohistochemistry; D017075:Laser Coagulation; D008214:Lymphocytes; D011184:Postoperative Period; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000473:pathology / Q000601:surgery*; D014945:Wound Healing
D000949:Histocompatibility Antigens Class II