ABSTRACT Purpose: An animal model of glaucoma is necessary for the study of its pathogenesis and treatment.The purpose of this study was to create open-angle glaucoma using a laser in rabbits. Methods: The trabecular meshwork of anaesthetized, adult, pigmented and albino rabbits was ablated internally using a diode laser via a gonioscopy lens, or externally through the limbus. In albino rabbits we used Chinese ink to pigment the angle and methylcellulose to open the iridocorneal angle. The eyes were examined weekly and histological assessment was performed. Results: The success rate of intra-ocular hypertension was low (15%) and a result of synechial angle closure. A narrow angle prevented access of the laser beam to the trabecular meshwork and promoted damage to the ciliary processes located on the posterior iris. Conclusions: Due to the unique anatomy of the rabbit eye, laser-induced glaucoma is difficult to achieve.To create a successful model it is necessary to widen the iridocorneal angle, selectively damage the trabecular meshwork and reduce inflammation. Key words: Chinese ink, diode laser, experimental glau- coma, methylcellulose, rabbit. INTRODUCTION To facilitate the study of any disease, finding an inducible experimental animal model that closely mimics the human disease is important. Laser-induced glaucoma has been reported in monkeys, 1–3 rabbits 4,5 and the rat. 6 Rabbits are attractive as laboratory animals because they are easy to handle, accessible and inexpensive. The aim of this study was to produce open-angle glaucoma using the diode laser in the rabbit. METHODS Adult pigmented (hybrid) and albino (New Zealand White) rabbits were used in this study and were handled in accor- dance with the ARVO (Association for Research in Vision and Ophthalmology) statement for the use of animals in ophthalmic and vision research. They were separated into four groups according to treatment. In the first three groups, internal photo-ablation of the trabecular meshwork (TM) with a slit-lamp mounted diode laser (Oculight ® GL; Iris Medical Instruments Inc., Mountain View, CA, USA) was performed with a Goldman gonioscopy lens (Haag-Streit AG, Berne, Switzerland) using a 75-μm spot size. The first group consisted of pigmented rabbits, with several receiving pilocarpine or iridoplasty to open the naturally narrow iridocorneal angle. The second group consisted of albino rabbits receiving internal laser. The third group were also albino rabbits receiving internal laser; however, they also received an intracameral injection of Ocucoat  (Stortz Ophthalmics, Clearwater, FL, USA) to widen the angle. The final group consisted of albino rabbits receiving external laser. The diode laser spot was aimed over the limbus and perilimbal blood vessels. In all albino rabbits 1 week before the first treatment, Chinese ink (20–50 μL) mixed with heparin was injected into the anterior chamber with the intention of pigmenting the TM in order to facilitate laser energy uptake. Treatment was performed by an experienced ophthal- mologist with the rabbits anaesthetized (Ketamine (Parke- Davis, Caringbah, Australia), 40 mg/kg i.m.; Xylazine (Troy Laboratories, Smithfield, Australia), 5 mg/kg i.m.) and the laser power (Table 1) set within the range used by previous studies. 4,5 Initially, a high laser power was used but this was gradually reduced in order to minimize collateral laser damage. Normotensive eyes were retreated with a similar power. Anaesthetized rabbits were examined using a slit-lamp 2 days after the laser treatment and every week thereafter. Australian and New Zealand Journal of Ophthalmology (1999) 27, 180–183 Clinical and Epidemiology Developing laser-induced glaucoma in rabbits Bradley Johnson, 1 Philip House, 1 William Morgan, 1 Xinghuai Sun 2 and Dao-Yi Yu 1 1 Physiology and Pharmacology Centre and McCusker Glaucoma Centre, Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, and 2 Department of Ophthalmology, Shanghai Medical University, Shanghai, China ■ Correspondence: Dr Dao-Yi Yu MD PhD, Centre for Ophthalmology and Visual Science, The University of Western Australia, 2A Verdun Street, Nedlands, Perth, WA 6009, Australia. E-mail:dyyu@cyllene.uwa.edu.au