Effect of posterior sub-tenon administration of triamcinolone acetonide on leukocyte dynamics in rat retinal microcirculation after panretinal photocoagulation.
OBJECTIVE
Macular edema is one of the serious side effects associated with panretinal photocoagulation (PRP). The inhibitory effect of triamcinolone acetonide (TA) on leukocyte-endothelial cell interactions in vivo after PRP was evaluated.


METHODS
Argon laser photocoagulation was performed in one half of the retinas in male Brown Norway rats. Experimental rats were injected with 2 mg TA (50-microL volume) in the posterior sub-Tenon space, and the vehicle-treated rats were injected with the same amount of saline (50 microL) immediately after PRP. Untreated rats were used as the control. Leukocyte dynamics in retinal microcirculation and retinal vessel diameters were evaluated 1 day after laser photocoagulation with the use of acridine orange digital fluorography. Retinal thickness was evaluated with optical coherence tomography.


RESULTS
The number of rolling leukocytes and accumulating leukocytes in the retina decreased by 66% in the TA-treated rats (P < 0.01) and by 24% (P < 0.05), respectively, compared with the number in the vehicle-treated rats. Retinal thickness in the vehicle-treated rats was significantly thicker than that in control rats 1 day after laser photocoagulation (P < 0.01). Retinal thickness in the TA-treated rats was significantly suppressed compared with that in the vehicle-treated rats (P < 0.05).


CONCLUSIONS
Sub-Tenon administration of TA significantly suppressed leukocyte dynamics in rat retinal microcirculation and decreased retinal edema after laser photocoagulation. The results suggest that the suppression of leukocyte-endothelial cell interactions in retinal microcirculation may be one mechanism responsible for the therapeutic effect of sub-Tenon TA on postlaser retinal edema.
Mizuno
Daisuke
D
Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan.
Matsubara
Akihisa
A
Ogura
Yuichiro
Y
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D003238:Connective Tissue / Q000187:drug effects; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D015590:Fluorophotometry; D005938:Glucocorticoids / Q000008:administration & dosage*; D007091:Image Processing, Computer-Assisted; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D017075:Laser Coagulation / Q000009:adverse effects*; D007962:Leukocytes / Q000502:physiology*; D008269:Macular Edema / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D008833:Microcirculation; D051381:Rats; D011914:Rats, Inbred BN; D012160:Retina / Q000601:surgery*; D012171:Retinal Vessels / Q000502:physiology*; D041623:Tomography, Optical Coherence; D014222:Triamcinolone Acetonide / Q000008:administration & dosage*
D005938:Glucocorticoids; D018799:Intercellular Adhesion Molecule-1; D014222:Triamcinolone Acetonide