2.4. Induction of Ocular Hypertension with Laser Photocoagulation (Rats)

Ocular hypertension was induced in Group 2 by laser photocoagulation of the TM and circumferential limbal vessels as previously described [21,22]. Anaesthesia was induced with intraperitoneal injection of Ketamine (100 mg/kg; Putney Inc, Portland, ME, USA)/Xylazine (10 mg/kg; Lloyd Inc, Shenandoah, IA, USA). Pupil constriction and subsequent opening of the iridocorneal angle was achieved with 4% pilocarpine hydrochloride ophthalmic solution (Sandoz, Princeton, NJ, USA). An OcuLight GLx 532 nm laser (Iridex, Mountain View, CA, USA) was used to deliver laser burns at 0.3 W, at a spot size of 100 µm and duration of 0.5 s. Three locations were photocoagulated: approximately 270° of the circumferential limbal vessels, episcleral veins branching from these limbal vessels and, finally, a trans-scleral/trans-corneal 360° burn of the TM/iridocorneal angle. Nasal vasculature was left uninjured to prevent ischemia.