Effects of stimulation of the ocular sympathetic nerves on IOP and aqueous humor flow.

Ocular sympathetic nerves were stimulated chronically in awake rabbits using electrodes unilaterally implanted on the cervical sympathetic trunk. IOP was measured by pneumatonometry and aqueous inflow was measured by fluorophotometry. In each animal, continuous trains of 1 msec pulses were delivered by means of a portable electrical stimulator.

Choroidal neovascularization in degenerative myopia: role of laser photocoagulation.

Laser photocoagulation of extrafoveal choroidal new vessels was performed in 19 eyes with degenerative myopia. Sixteen eyes required only one treatment. Three eyes required more than one because of incomplete closure of the new vessels after the first treatment.

Size and shape of bovine interphotoreceptor retinoid-binding protein by electron microscopy and hydrodynamic analysis.

Individual molecules of interphotoreceptor retinoid-binding protein (IRBP), a protein likely to be important in the visual cycle, were visualized by means of electron microscopy. IRBP was coated with a very thin layer of tungsten and photographed by dark-field imaging. IRBP is seen to be a flexible, elongated molecule about 24 nm in length by 3-4 nm in width (statistical modes).

Vitreous hemorrhage secondary to age-related macular degeneration.

The clinical features of two patients with vitreous hemorrhage secondary to age-related macular degeneration and the histopathological findings in one of these cases are reported. Twenty additional cases are reviewed and compared with previously reported series. In patients with vitreous hemorrhage secondary to age-related macular degeneration, the appearance of vitreal blood is often preceded by extensive subretinal hemorrhage.

Polar-apolar characteristics and fibrillogenesis of glycosylated collagen.

To find the effect of carbohydrate on collagen fibrillogenesis, type I skin collagen was glycosylated by glycosyltransferase, and type II cartilage collagen was deglycosylated by glycosidase. The secondary structures remained unchanged, but the tertiary structures were altered, as shown by increased TNS fluorescence of the bound probe in the glycosylated form. Since TNS binds preferentially to the hydrophobic region of a protein molecule, glycosylation caused an apparent increase in the available hydrophobic sites for the dye.

Effects of visible-light irradiation on vitreous structure in the presence of a photosensitizer.

Sensitized photo-induced changes of vitreous structure were investigated using both in vivo and in vitro model systems. In the former, rabbit eyes were injected with the photosensitizer riboflavin, and in the latter, calf vitreous samples were treated with riboflavin or Methylene Blue prior to irradiation with white light. The active species of oxygen, i.

Improved technique for storage of tear microvolumes.

The authors have developed an improved technique for storage of fluid microvolumes prior to osmolality measurement. To date, tear samples have been stored in a column of Cargilles B immersion oil contained within a capillary tube, sealed at one end with Critoseal. Covering the open end of this tube with Parafilm now provides reliable storage of 0.

A hapten model of topically-induced ocular anaphylaxis in the rat.

A hapten (DNP) model of topically induced ocular anaphylaxis has been developed. Rats immunized with DNP-Ascaris were skin-tested with DNP-bovine serum albumin (DNP-BSA) and Evans blue and challenged topically with varying amounts of di-DNP-lysine. The degree of clinical conjunctival edema was assessed, and eye tissues were evaluated histologically.

A new rabbit model for keratoconjunctivitis sicca.

The authors created a new rabbit model for keratoconjunctivitis sicca by cauterizing the lacrimal gland excretory duct and surgically removing the nictitating membrane and harderian gland. Although the slit-lamp examination findings remained normal for the first 8 wk postoperatively, tear-film osmolarity was elevated by postoperative day 1. Corneal epithelial glycogen levels declined progressively, and conjunctival goblet cell density remained decreased.

Anchoring fibrils form a complex network in human and rabbit cornea.

Anchoring fibril distribution, depth of penetration into the stroma, and pattern of histochemical localization of type VII collagen (the anchoring fibril collagen) were studied in normal human and rabbit corneas. Electron micrographs of cross sections and sections taken parallel to the basement membrane demonstrate that anchoring fibrils insert into the basal lamina and then splay out laterally. They are more readily seen in sections taken parallel to the basal lamina, where they are observed to form a complex branching and anastomosing network below the basal lamina.

Effectiveness of silicone oil removal from rabbit eyes.

Silicone oil (1000 and 12,500 cs) and fluorosilicone oil (1000 and 10,000 cs) were dyed red and injected into a gas-created space in the vitreous cavity of 51 rabbit eyes. Later the oils were removed from the vitreous cavity either by lavage with balanced salt solution (group 1, 27 eyes) or by injecting a sodium hyaluronate solution, followed by lavage with balanced salt solution (group 2, 24 eyes). The average amount of oil retained in the vitreous cavity in group 1 was 0.

Effects of light and dark environments on macaque and human fixational eye movements.

Eye position of two macaques and two humans was recorded while they detected the unpredictable dimming of a fixation spot in a dark or a light environment. Fixational saccades often had complex waveforms that resulted from clustering of two or more saccadic displacements with no intervening drift periods. In the dark, all subjects had low frequencies of saccade clusters (0.

Use of high-density fluorosilicone oil in open-sky vitrectomy.

During prolonged open-sky vitrectomy, fluid accumulates in the suprachoroidal and subretinal spaces and the resultant ballooning of the choroid and of the retina interferes with the surgery. Fluorosilicone oil (polymethyl-3,3,3-trifluoropropylsiloxane) with a specific gravity of 1.28 was tested for use as a temporary vitreous substitute during open-sky vitrectomy.

Ageing of the vitreous.

Changes that occur in the vitreous during ageing contribute to a variety of vitreo-retinal disorders. These age-related changes are rheologic, biochemical, and structural in nature. Our current knowledge of these ageing changes is reviewed.

Topical arachidonic acid: a model for screening anti-inflammatory agents.

Products of arachidonic acid metabolism, prostaglandins and leukotrienes, play an important role in ocular inflammation. In this study, we investigated the efficacies of the cyclo-oxygenase inhibitors (aspirin, indomethacin, and piroxicam) and the lipoxygenase inhibitors (N-hydroxy-arachidonamide (AH) and phenidone) in reducing ocular inflammation induced by arachidonic acid. Administering arachidonic acid topically (0.