Blood-retinal barrier breakdown caused by diode vs argon laser endophotocoagulation.
We compared the effects of argon and diode laser endophotocoagulation on blood-retinal barrier breakdown using real-time magnetic resonance imaging following intravenous gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) injection. Endophotocoagulation was performed on eyes of pigmented rabbits with either the argon or the diode laser to produce ophthalmoscopically similar lesions. Magnetic resonance imaging studies were performed either 2 or 7 days after laser treatment, and coronal T1-weighted proton images were obtained in the first 20 minutes following Gd-DTPA injection. The mean signal intensity over a region of interest in the vitreous cavity was analyzed, and an initial rate analysis was performed on each time-course curve. Two days after treatment, argon laser-treated eyes showed significantly greater leakage of Gd-DTPA than diode laser-treated eyes. The leakage in both groups was substantially reduced by posttreatment day 7. Histopathologic examination performed 2 days following photocoagulation showed less damage of the retinal pigment epithelium and more severe occlusion of the choriocapillaris and deep choroidal vessels in diode laser-treated eyes. These changes may serve to explain the observed differences in Gd-DTPA leakage.
Sato
Y
Y
Duke University Eye Center, Durham, NC 27710.
Berkowitz
B A
BA
Wilson
C A
CA
de Juan
E
E
D000818:Animals; D001813:Blood-Retinal Barrier; D005260:Female; D053685:Laser Therapy / Q000009:adverse effects; D008028:Light Coagulation / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D011817:Rabbits; D012160:Retina / Q000473:pathology*; D012164:Retinal Diseases / Q000175:diagnosis / Q000209:etiology / Q000473:pathology