Purpose
To evaluate a new model of tractional retinal detachment (TRD) in the rabbit eye using Laser and VEGF injection. Such a model may help us better understand similar diseases in humans like diabetic retinopathy and traumatic retinal detachment.
Methods
Laser photodisruption of Bruch’s membrane in the right eyes of rabbits was followed by either intravitreal injection of 100µg/0.1mL VEGF (Treatment group: n=15) or 0.1 mL BSS (Control group: n=5); these injections were repeated weekly for a total of 3 injections. Six Argon Laser shots were focused on Bruch’s membrane with the following settings: spot size, 100µm; power, 800 mW; duration, 100 ms. Fundus imaging using fluorescein angiography (FA) and optical coherence tomography (OCT) were performed at baseline and every 2 weeks for a 3-month follow-up period. Finally, all animals were sacrificed and eyes were harvested for histopathology using H&E stains and scanning electron microscopy (SEM) and immunostaining using GFAP. Animal procedures were conducted in accordance with USC IACUC and ARVO Guidelines for animal use.
Results
All rabbits in the treatment group showed TRD starting 2 weeks after the 1st dose of VEGF, none of the control group showed TRD. On FA imaging, laser-treated chorioretinal lesions showed dye leakage in all rabbits in the treatment group during the 3 month follow-up period, while the control group showed dye leakage in the first week only. The treatment group showed tractional membranes, epiretinal fibrosis, and TRD in OCT, while the control group showed partial posterior vitreous detachment (Fig.1). Histopathologic studies confirmed the fibrocellular nature of the developing epiretinal membranes explaining the progression of TRD during the follow-up (Fig 2).
Conclusions
Laser photodisruption of Bruch’s membrane followed by repeated intravitreal VEGF injection produces a consistent reproducible model of TRD in the rabbit eye.
Keywords: 697 retinal detachment •
578 laser