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Abstract #11973 Published in IGR 7-1
Topically administered timolol and dorzolamide reduce intraocular pressure and protect retinal ganglion cells in a rat experimental glaucoma model
Seki M; Tanaka T; Matsuda H; Togano T; Hashimoto K; Ueda J; Fukuchi T; Abe HBritish Journal of Ophthalmology 2005; 89: 504-507
AIMS: This study sought to elucidate the effects of timolol and dorzolamide on intraocular pressure (IOP) and retinal ganglion cell (RGC) death in an experimental model of glaucoma in rat. METHODS: Mild elevation of IOP was induced in rats by intracameral injection of India ink and subsequent laser trabecular photocoagulation. IOP was measured before the surgical procedures and weekly thereafter. Timolol (0.5%), timolol XE (0.5%), dorzolamide (1%), and artificial tears (vehicle) were topically applied daily. Retinal sections were prepared for histology to determine RGC number. RESULTS: Timolol, timolol XE, and dorzolamide induced a significant reduction in IOP (p < 0.05) and counteracted the reduction in RGC number that occurred in vehicle treated glaucomatous eyes (p < 0.05). The coefficient of correlation between RGC number and IOP was significant in the dorzolamide treated group (r = -0.908, p < 0.005), but not in other groups (p > 0.05). CONCLUSIONS: Both timolol formulation and dorzolamide reduced IOP and protected RGCs in a rat model of experimental glaucoma. It cannot be ruled out that timolol might protect RGCs by additional mechanisms other than simply lowering of IOP.
Dr. M. Seki, Division of Ophthalmology and Visual Science, Graduated School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi, Niigata, Niigata 951-8585, Japan
Classification:
11.3.4 Betablocker (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)
11.5.2 Topical (Part of: 11 Medical treatment > 11.5 Carbonic anhydrase inhibitors)
11.8 Neuroprotection (Part of: 11 Medical treatment)