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Biomedical subjects

G R Reiss

Publications and source records attributed to G R Reiss.

7 recordsLinked to original sources
PubMed1989

Is the high concentration of ascorbic acid in the eye an adaptation to intense solar irradiation?

Ascorbic acid is known to exist in high concentration in the aqueous humor of the eye in many species. It has been observed that diurnal mammals have a very high concentration in aqueous humor whereas nocturnal mammals do not. It has been hypothesized that ascorbic acid protects the eye from the harmful effects of sunlight. We have discovered that of two closely related species of spiny mice, the diurnal species (Acomys russatus) has a concentration in aqueous humor that is 35 times higher than that of the nocturnal species (Acomys cahirinus). Studies of these two species may be fruitful to extend what is known about adaptation of the eye to protect itself from intense solar radiation.

Adaptation, Physiological↗
PubMed1986

Ascorbic acid levels in the aqueous humor of nocturnal and diurnal mammals.

Ascorbic acid concentration is known to be very high in the aqueous humor of humans and most animals. The role it might play in ocular function is a subject of conjecture. Some have proposed that it might protect the eye against light-induced damage. We examined the aqueous humor from 22 species of mammals to determine the range of levels and to see if there was a correlation with behavior. A wide range of ascorbic acid levels in the aqueous humor was found. Most of the animals considered to be diurnal had higher ascorbic acid levels than the nocturnal animals. This would suggest that ascorbic acid in the aqueous humor may play a protective role in those animals who are most exposed to light. Regardless, any theory proposing a role for ascorbic acid in the eye in mammals must take the wide range of ascorbic acid levels into account.

Animals↗
PubMedDate not supplied

Infectious crystalline keratopathy.

A 57-year-old white female was noted to have unusual intrastromal crystalline-like opacities in her failing right corneal graft five months after transplant surgery. Cultures grew Streptococcus viridans; since the graft was failing it was replaced and sent for pathologic examination. H&E stains revealed intrastromal pockets of basophilic material between the lamellae; there was a notable absence of inflammatory cells. Gram's stain showed the basophilic material to be gram positive and transmission electron microscopy confirmed the presence of intrastromal pockets of bacteria. The term "infectious crystalline keratopathy" was coined by Meisler for this entity, which occurs following longterm topical steroid usage. The quite clinical appearance may make its infectious etiology unapparent. Management consists of discontinuation of the steroids and the administration of antibiotics; continued infection, corneal scars, or graft failure may occur and transplantation is then required.

Cornea↗
PubMedDate not supplied

Laser trabeculoplasty.

Over a decade, laser trabeculoplasty has evolved from being a novel new treatment to one that is a commonly accepted intervention in the management of open-angle glaucoma. Despite its widespread use, however, there are still many unanswered questions about laser trabeculoplasty, including its mechanism of action and the ideal treatment parameters. In this review, we will discuss the history of the technique, the clinical experience, and some of the experimental studies that have been conducted to answer the questions regarding its mechanism of action.

Glaucoma, Open-Angle↗