Investigative ophthalmology最新文献

4-Biphenylacetic acid (BPAA),a prostaglandin-synthesis inhibitor, was tested for its effects on prostaglandin-related, laboratory models of ocular inflammation. Topically applied, BPAA inhibited arachidonic acid, but not prostaglandin E-induced increases in rabbit intraocular pressure (IOP). BPAA inhibited the IOP response to alkali burn and altered IOP changes following paracentesis. In vitro, BPAA inhibited prostaglandin production from arachidonic acid in cell-free preparations of rabbit uvea. It is suggested that BPAA may be useful for the therapy of ocular inflammatory disease.

Previous studies have shown that approximately 40 per cent of the corneal endothelial cells can be lost at the time of intraocular lens insertion. Momentary contact between the methacrylate surface and the endothelial cells causes an adhesion between these surfaces and results in extensive cell damage upon separation of the surfaces. This type of damage appears to be due to a biophysical interaction between these surfaces and may be avoidable by altering the surface of the lens.

Low-molecular-weight retinol- and retinoic acid-binding proteins were shown to be present in the soluble fraction of human retinal tissue but absent from human fibroblasts grown in tissue culture. By the use of gel filtration and comparison with bovine retinal tissue, the human intracellular binding proteins were found to have molecular weights of approximately 17,000 daltons, which are comparable to the molecular weights of bovine intracellular binding proteins. The quantity of retinoic acid bound exceeded that of retinol by about eightfold.

The interaction between retinol-binding protein and normal bovine pigment epithelium has been studied with the use of iodinated retinol-binding protein isolated from the plasma of patients with the recessive form of retinitis pigmentosa and of normal subjects. It is concluded that the capacity of the plasma carrier protein to interact with the retinol-binding protein receptor of bovine pigment epithelium is unimpaired in retinitis pigmentosa with autosomal recessive inheritance.

AY9944, an inhibitor of cholesterol biosynthesis, was injected into albino rats and the ocular tissue was studied by light and electron microscopy. Abundant lamellar inclusion bodies accumulated in various cells of the eye, especially in the ganglion cells of the retina and glial cells of the optic nerve. Prolonged administration of this drug resulted in degeneration of retinal ganglion cells and oligodendroglial cells of the optic nerve. Micro-organelles of the inclusion body-laden cells were otherwise normal in their appearance. The electron microscopic appearance of these inclusion bodies and their distribution in the ocular tissues closely resembled those of Niemann-Pick diseasees.

Depressed aqueous humor glucose and ascorbic acid levels returned to control values within 14 days following a 20 sec, 6 mm. diameter, 1N sodium hydroxide burn of the rabbit cornea. These corneas did not ulcerate or perforate. After a 20 sec., 12 mm. diameter, 1N sodium hydroxide burn, aqueous humor glucose levels returned to normal values, but ascorbic acid levels remained significantly depressed for up to 30 days. These corneas became markedly ulcerated in about 60 per cent of animals and frequently perforated. Following 12 mm. alkali burns, rabbits treated daily with 1.5 Gm. of subcutaneous ascorbic acid rarely developed corneal ulcerations and the corneas did not perforate. It is suggested that exogenous maintenance of adequate aqueous humor levels of ascorbic acid overcomes the relatively scorbutic state of the anterior segment induced by a 12 mm. alkali burn, thereby impairing the development of corneal ulceration and perforation. Elevated aqueous humor levels of ascorbic acid had no influence on corneal epithelial cell migration patterns following alkali burns.

The development of experimental disciform edema and necrotizing keratitis in the corneas or rabbits following intrastromal inoculation with the RE strain of herpes simplex virus is described. Following an initial episode of conjunctivitis and epithelial keratitis, a mild, centrally localized, stromal edema developed on the fifth day. Stromal edema, opcification, and neovascularization of the cornea reached maximum severity on the seventh to twenty-second day, and began to fade in most eyes thereafter. On the twenty-ninth day most corneas have attained a resolved state characterized by subepithelial granular opacities. Several eyes were observed which developed central necrotizing keratitis. Marked similarities between the animal model and human herpetic stromal keratitis were apparent. Histological observations show that early necrotizing keratitis in the rabbit is characterized by an infiltration of plasma cells and lymphocytes in the limbus, with polymorphonuclear leukocytes, lymphocytes, and macrophages in the central cornea.

A population study of measured inflow values of eyes of a group of adult male rhesus monkeys was done with a randomized technique of constant-pressure infusion. Each eye was presented with a sequence of 18 4-minute runs, consisting of three infusion runs for each of six pressures, in which the order of appearance of a given pressure had been randomized. A statistical analysis of the results indicates that only the independent variables of infusion pressure, type of anesthetic, and position in the sequence of the 18 infusion runs had a significant effect upon measured inflow.

Pilocarpine was administered to a selected group of ocular hypertensive subjects in the form of a synthetic biosoluble matrix inserted into the conjunctival cul-de-sac. Satisfactory lowering of the intraocular pressure resulted, with a minimum of subject intolerance. The decreased pressure response was significant in some cases for greater than 24 hours. Drug delivery by soluble inserts offers promise as a convenient and effective mode of therapy.