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Biomedical subjects

G A Fishman

Publications and source records attributed to G A Fishman.

213 records · Page 12Linked to original sources

Retinal and pigment epithelial alterations over choroidal malignant melanomas.

Although in some cases orange or yellow-orange pigment overlying a malignant choroidal melanoma may represent lipofuscin, a case is presented which showed extensive yellow-orange coloration overlying a malignant choroidal melanoma without any demonstrable lipofuscin on histopathologic and electron microscopic analysis. Our findings suggest that other mechanisms, such as serous fluid or lipid deposition within retinal cystoid spaces or diffuse drusen, can clinically stimulate the yellow-orange pigment associated with lipofuscin.

Adult↗

Stereoacuity testing in patients with retinal and optic nerve disorders.

A study comparing the relative sensitivity for detecting abnormal stereoacuity in patients with retinal or optic nerve disease on clinically used stereoacuity tests is not available. It is also not apparent from the ophthalmic literature if optic nerve or retinal diseases are likely to have a greater impact on stereoacuity performance. We were also interested in determining a level of visual acuity loss that would likely results in an impairment of stereoacuity on these clinical tests. Forty-two patients with various retinal and optic nerve disorders and eighteen normal subjects were evaluated for stereoacuity using three tests: Titmus Stereoacuity Test (TST), Randot Stereoacuity Test (RST), and TNO Stereoacuity Test (TNO). The performance on these three stereoacuity tests was compared with the normal subjects. Additionally, TST scores from our patients were compared to predicted TST scores derived from a previously published nomogram. For patients with retinal and optic nerve disease, an abnormal score on one clinical test of stereoacuity was likely to predict an abnormality on the other tests. Performance on the TST relative to the predicted value derived from a nomogram was not significantly different for patients with retinal vs. optic nerve disease. With some exceptions, patients with visual acuities of 20/30 or worse in at least one eye were likely to show abnormal stereoacuity.

Adolescent↗

Ocular phototoxicity: guidelines for selecting sunglasses.

Within the last two decades appreciable laboratory and epidemiologic evidence has accumulated to support the notion that near ultraviolet radiation and lower wavelength visible light may be hazardous to the human lens and retina. However, a substantial number of commercially available sunglasses are being manufactured without apparent regard for these potential hazards. This review surveys the mechanism(s) for phototoxic damage to the eye, outlines persons at potentially greatest risk of injury, and summarizes recommendations for the selection of optimally efficient sunglasses.

Eye Injuries↗

Basic principles of clinical electroretinography.

Before applying the technique of electroretinography to the investigation of retinal disorders, it is imperative to understand the cells within the retina that generate its component waveforms and the manner in which various stimuli and background conditions modify their amplitude and isolate cone and rod contributions.

Dark Adaptation↗

Electroretinography and inherited macular dystrophies.

With judicious application, conventional electroretinographic recordings can provide meaningful diagnostic information on patients with hereditary macular dystrophies. In some patients, characteristic fundus lesions in addition to already known information on predictably normal electrophysiologic findings should obviate the need for implementation of electroretinographic investigations. In other macular dystrophies, such recordings are necessary for a definitive diagnosis or for monitoring photoreceptor cell deterioration. This review discusses six of the most frequently encountered inherited macular dystrophies with consideration as to when and why electroretinographic recordings should be implemented in the study of these disorders.

Diagnosis, Differential↗

Progressive human cone-rod dysfunction (dystrophy).

The author has classified progressive human cone-rod dysfunction into primary and secondary types. The primary type, identified by early ERG cone and usually also rod abnormalities, was further subdivided into types 1 and 2 based on, amoung other distinguishing characteristics, the extent of associated retinal pigment epithelial defects. Secondary cone-rod dysfunction apparently results from disease initially affecting the retinal pigment epithelium. Initially normal ERG findings and the presence of flecks characterize this (type 3) progressive cone-rod dysfunction.

Adolescent↗

Cone-rod dystrophy in the Guinea baboon.

Three stages of macular degeneration associated with diffuse cone-rod dystrophy have been described in a Guinea baboon (P papio) colony. Clinically, the affected animals displayed abnormal behavior associated with decreased vision. Ophthalmoscopically, the lesion in the macula was the only change observable in early cases; retinal vessel attenuation and optic disc pallor were seen only in the advanced cases. The hyperfluorescence of the maculae was the result of loss of pigment in the pigmented epithelium. Electrophysiology supported a cone-rod sequence of this retinal dystrophy. Histologic examination confirmed the theory that the dystrophy began in the cone outer segment but eventually involved all the photoreceptors.

Animals↗