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Abstract #10131 Published in IGR 6-1
Influence of peripheral iridectomy on intravitreous penetration of topical nipradilol
Mayama C; Tomidokoro A; Araie M; Mizuno KCurrent Eye Research 2004; 28: 129-133
PURPOSE: Penetration of drugs from the anterior chamber to the vitreous is substantial in aphakic eyes, but negligible in normal phakic eyes. The purpose of this study was to investigate the effect of the presence of peripheral iridectomy (PI) which bypasses the iris-lens diaphragm on drug penetration from the anterior chamber to the vitreous. METHODS: Twelve Japanese White rabbits underwent PI in a randomly chosen eye, and the same procedure, except for removal of the peripheral iris, in the contralateral eye. Nine weeks after the procedure, topical instillation of 20 μl 1% nipradilol into the both eyes was repeated three times at five-minute intervals, and two hours later the animals were sacrificed and both eyes were enucleated. Concentrations of nipradilol in the aqueous and vitreous were determined using a high-performance liquid chromatography. RESULTS: Concentrations of nipradilol were significantly greater in eyes with PI than those in the contralateral control eyes in the aqueous (5636 ± 1688 versus 2835 ± 663 ng/g, mean ± standard error, n = 12, p = 0.0028) and in the anterior vitreous (11.9 ± 2.5 versus 5.6 ± 1.0 ng/g, p = 0.0047), but not in the posterior vitreous or in the posterior retina-choroid. Ratios of nipradilol concentrations in the anterior or posterior vitreous compared to those in the aqueous were not significantly different between both eyes. CONCLUSIONS: The presence of PI had little effect on the penetration of topically instilled nipradilol from the anterior chamber to the vitreous.
Dr. C. Mayama, Department of Ophthalmology, University of Tokyo School of Medicine, Japan. cmayama-tky@umin.ac.jp
Classification:
11.3.4 Betablocker (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)