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Biomedical subjects

J D Wirtschafter

Publications and source records attributed to J D Wirtschafter.

At least 73 records · Page 4Linked to original sources
PubMed1978

Transaqueous diffusion of acetylcholine to denervated iris sphincter muscle: a mechanism for the tonic pupil syndrome (Adie syndrome).

The accepted hypothesis for the pathophysiology of tonic pupil syndrome (Adie syndrome) was reexamined in light of recent developments concerning denervation supersensitivity of cholinergically innervated smooth muscle. Kinetic analysis suggests that enzymatic hydrolysis is unimportant relative to convective diffusion in the turnover of acetylcholine in the aqueous humor. We postulate that the greater response to near stimuli than to light stimuli and the delay in iris sphincter contraction and relaxation can be explained by release of acetylcholine from the neuromuscular junction of the ciliary muscle followed by transaqueous diffusion to receptor sites on denervated, supersensitive iris sphincter muscle.

Acetylcholine↗
PubMed1977

Intraocular axonal swelling produced by partial, immediately retrobulbar ligature of optic nerve.

This is the first report of an experimental intraorbital ligature producing papilledema characterized by axonal swelling and accumulation of mitochondria in the lamina retinalis of the optic disc of rhesus monkeys subjected to immediately retrobulbar ligature of a portion of the optic nerve. This is an improved technique for investigating the pathogenesis of papilledema and optic neuropathy.

Animals↗
PubMed1976

Bias of the cover test in the diagnosis of alternating tropia.

In the evaluation of patients with alternating tropia, all errors tends to falsely overclassify the fixation pattern as free alternation and underestimate monocular fixation. This bias is particularly undesirable in infants when the cover test is used because more direct measurements of visual acuity are not possible.

Fixation, Ocular↗
PubMed1976

A stereological analysis of venous nicking observed at retinal arteriovenous crossings.

The accepted hypotheses for the explanation of retinal venous nicking are critically reviewed and an alternative hypothesis based on a stereological analysis is presented. The ophthalmoscopic appearance of retinal venous nicking is best explained by partial collapse of the vein with the major axis of the venous cross section at right angles to the internal limiting a membrane of the venous blood flow nor of the likelihood of tributary vein occlusion. A partially collapsed vein may be very sensitive to small changes in intraocular pressure. Patients with impending tributary vein occlusion may benefit from reducing intraocular pressure.

Fluorescein Angiography↗