[A study of experimental carbomer glaucoma and other experimental glaucoma in rabbits]

To establish models of experimental glaucoma in rabbits to investigate the treatment of glaucoma.

Twenty-one normal albino rabbits weighing 2.5 - 3.0 kg were studied. The rabbits were divided randomly into 4 groups: I, II, III and IV. Anterior chamber injection of 0.1 ml of 0.3% carbomer (I), 0.2 ml of methylcellulose (II), 0.2 ml of compound methylcellulose (III) and subconjunctival injection of 5 mg of dexamethasone (IV) were performed respectively on them to induce glaucoma. The intraocular pressure (IOP) was monitored with a Tono-pen XL tonometer several times prior to injection and 2 times per week after injection. The basic IOP in every group served as control.

Experimental glaucoma occurred in eleven of twelve eyes in group I and IOP lasted from 20 to 50 days. The mean IOP levels were 29 - 35 mmHg (1 mm Hg = 0.133 kPa) and the peak IOP levels were 37 - 45 mm Hg. The IOP in 2 out of 10 eyes in group II increased to 22 - 50 mm Hg and lasted for 3 days. The IOP of 1 out of 10 eyes in group III increased to 25 - 40 mm Hg and lasted for 4 days. The IOP in eyes of group IV increased only 3 mmHg in the mean and lasted for one week. According to the standard, IOP above 22 mmHg for one week as the successful experimental glaucoma, group II and III were not the ideal ones and group IV was a failure.

Experimental glaucoma model induced by carbomer has the advantages of producing moderate and sustained IOP elevation. The model is easy to be carried out. It is simple, reliable, and useful for investigating optic nerve and retinal damage in glaucoma and testing the toxicity and efficacy of various therapies.