KNOWLEDGE of the means by which substances enter and leave the eye, usually referred to as " aqueous-humour dynamics ", is essential for an understanding of the factors contributing to the control of the intra-ocular pressure. In non-living systems, when a membrane separates two concentrations of a substance in a solution to which the membrane is permeable, this substance travels across the mem...

A group of 26 subjects with myotonic dystrophy were studied with fluorophotometry to evaluate the relationship between aqueous humor dynamics and the hypotony found in this disorder. All 26 received topical fluorescein to determine the anterior chamber elimination coefficient; five received systemic fluorescein to evaluate the integrity of the blood-aqueous barrier. The group has a mean intraoc...

The aim of this study was to increase bioavailability of the antiviral drug acyclovir (ACV) when administered by the ocular route. For this purpose, a new lipophilic derivative of acyclovir was synthesized, both possessing greater lipophilicity and providing the formation of a homogeneous water dispersion with higher amount of ACV than the aqueous solution of the parent drug. This was done by c...

Certain forms of glaucoma are associated with displacement of the iris from its normal contour. We present here a mathematical model of the coupled aqueous humor-iris system that accountsfor the contribution of aqueous humor flow and passive iris deformability to the iris contour. The aqueous humor is modeled as a Newtonian fluid, and the iris is modeled as a linear elastic solid. The resulting...

NOVEMBER/DECEMBER 2011 CATARACT & REFRACTIVE SURGERY TODAY 35 E ndoscopic cyclophotocoagulation (ECP) involves laser ablation of the ciliary body epithelium under direct endoscopic visualization. The result is a lowering of IOP through a decrease in the production of aqueous humor. ECP can effectively treat most types of glaucoma. Often combined with phacoemulsification, ECP has been proven saf...

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The acute effects of topical pilocarpine 4 per cent, administered to one eye, have been studied in replicate experiments in young volunteers. One hour after medication administration the intraocular pressure was significantly lower. The magnitude of the reduction exceeded that predicated from the significant increase of true facility of outflow. This is explained by the observation of a signifi...

No oxygen was detected on the corneal surface of human subjects breathing air or almost pure oxygen. These results suggest that the epithelium obtains all its oxygen fro the air or the palpebral conjunctiva and that the endothelium is supplied with oxygen solely by the aqueous humor.

PURPOSE To determine whether there is a circadian change of the concentration of C-type natriuretic peptide (CNP) in rabbit aqueous humor. METHODS Forty-one male white New Zealand rabbits were submitted to a 12 h light and 12 dark lighting schedule; lights on was at 0 h, lights off at 12 h. C-type natriuretic peptide was assayed at 3 light (2 h, 6 h and 10 h) and 3 dark (14,18 and 22 h) times...

introduction: arsenic is known as a carcinogenic compound in drinking water . it can cause acute and chronic effects on human health. in this study, the effect of polyamidoamine dendrimer generation 3(pamam g3) as adsorbents for removal of arsenic (v) from aqueous solutions was evaluated.     methods: adsorption experiment was studied in batch system and the effect of different variables like p...