Inferior conus: a new hypothesis for associated field defects

A case of bilateral inferior conus is reported; relative scotomas were found to be congruent with the location of the conus. Existing theories, proposed to account for scotomas associated with inferior conus, are discussed. A new theory is proposed.

Annual review of section on ocular disease: diseases of the optic nerve, tracts, and visual cortex

The ophthalmic literature dealing with diseases of the optic nerve, tracts, and visual cortex was reviewed for the period November 1977 to December 1978. Fifty-nine papers of interest to optometrists have been abstracted. Main areas of interest include: role of axoplasmic transport in production of disc edema and cotton-wool spots; ocular effects of local and systemic vascular disturbances; congenital abnormalities of the eye alone and in association with other bodily malformation; field testing, including an ingenious ophthalmoscopic method which can lead to detection of very small scotomas; a new quantitative method for assessing integrity of the optic nerve in multiple sclerosis and related conditions; stimulating questions on the development of optic atrophy and on its relation to retinal vascularity; considerations of acquired and congenital abnormalities of the cavernous sinus and their ocular manifestations; swinging-flashlight test in hemianoptic patients; a case of subacute sclerosing panecephalitis; methods to enhance magnification during opthalmoscopy; methods enabling a closer investigation of the retinal nerve fiber layer.

Ocular manifestations of systemic childhood diseases: some systemic diseases are no respecters of age

Many diseases commonly thought to affect the older population may be present in children. Examples are given of conditions which might be unsuspected in children and which might, therefore, be undiagnosed until severe, irreversible damage is done.

Presumed ocular toxoplasmosis: some clinical observations

Ophthalmoscopic appearances of congenital and acquired presumed ocular toxoplasmosis are described. Four illustrative cases of presumed ocular toxoplasmosis are discussed, with some emphasis on related general health history. Some speculations are offered to account for the varied ophthalmoscopic appearances of these lesions.

Disc vascularity in Down's syndrome

Ocular fundus photographs of 100 eyes were obtained from an institutionalized population of patients with Down's Syndrome (66 males, 34 females). The vascularity of the optic nerve head was assessed in each photograph by counting the number of arterioles, venules, and fine vessels crossing the disc margin. The results of this analysis were compared to similar data obtained from 100 ocular fundus photographs of normal patients and show that there are more large vessels crossing the disc margin in those with Down's Syndrome.

Effect of meridional disparity on depth perception

When a meridional-size lens is used to provide magnification in the horizonal meridan for one eye the resulting stereopsis distortion is readily accounted for in the terms of the binocular disparity caused by changed angular relations. When the same size lens is used to magnify the vertical meridian for one eye there is an opposite stereoscopic distortion for which is no ready geometric explanation. A perceptually induced mechanism operating in the vertical meridian has been suggested by Ogle. In the present experiment, apparatus was designed to introduce disparity of binocularly fused targets successively in each of several oblique meridians independent of the stereopsis measuring targets. Unlike the above-mentioned results obtained with size lenses, the induced stereoscopic distortion was in the same direction and of essentially the same magnitude for disparity in every meridian. It would follow that the perceptually induced mechanism is not exclusive to the vertical meridian.

Comparison of anesthetic agents in the sea otter

Five anesthetic agents (C1744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

Congenital malformations of the optic-nerve head

Normal anatomical variations of the eye are a constant source of interest to the clinician. This is particularly true for the optic-nerve head, where neural, vascular, and supportive tissue converge, each with its own variations. Such diverse anomalies as cleft palate, reduced visual acuity, visual-field loss, and distortions of the optic-nerve head may all be related to a single factor affecting embryonic or later development. This paper presents a number of nerve-head malformations in the context of their embryonic development, clinical appearance, and implications for visual function.

Diseases of the optic nerve, tracts, and visual cortex: an annual review of the ophthalmic literature

The ophthalmic literature dealing with diseases of the optic nerve, tracts, and visual cortex was reviewed for the period November 1976 to November 1977. Thirty-three papers of interest to optometrists have been abstracted. Main areas of interest include response of posterior segment to anterior-segment disturbances; structural anomalies in nerve-head region, including a new potential cause for hypoplasia of optic nerve; speculation on possible common origins of RPE/Bruch's membrane disturbances and endothelium/Descemet's membrane disturbances; a vascular hypothesis for pathogenesis of optic-nerve-head drusen; an explanation for reversibility of infantile glaucomatous cupping; glaucomatocyclitic crisis; the role of axoplasmic flow in papilledema; new developments in field testing for early glaucomatous loss; effects of cerebral vascular accidents on color vision; and two interesting instances of systemic disease with ocular manifestations.

Review of diseases of the optic nerve, optic tract, and visual cortex: 1975-76

The ophthalmic literature dealing with diseases of the optic nerve, the optic tracts, and the visual cortex was reviewed for the period November 1975 through November 1976. Twenty-nine papers on topics of interest to optometrists were abstracted. The main areas of interest include: papilledema and optic atrophy (with ophthalmoscopic signs of both optic atrophy and papilledema); giant-cell arteritis; papillitis; interesting malformations of the face, palate, and orbital position that occur in conjunction with microphthalmus, situs inversus, and hypoplasia and aplasia of the optic nerve; the proposed association of myopia with unusual eyebrows; myelinated nerve fibers at the nerve head; pigment anomalies; the continuing discussion of nerve-head blood supply; an unexpected cause for nerve-head neovascularization; the importance of the swinging-flashlight test in the diagnosis of glaucoma; an unusual type of glaucomatous cupping; doubts about the peripapillary "halo" as a sign of glaucoma; new uses for old field tests; and new methods of ocular photography.

Diseases of the optic nerve, tracts, and visual cortex: an annual review of the ophthalmic literature

The ophthalmic literature dealing with diseases of the optic nerve, tracts, and visual cortex was reviewed for the period September 1973 to November 1974. Eighteen papers dealing with topics of interest to optometrists have been abstracted. Principal subjects include: relation of central serous retinopathy to pregnancy, a stimulating discussion of the role of elastic tissue degeneration in formation of angioid streaks, methods of assessing internal carotid artery disease, ophthalmoscopy versus tangent screen evaluation, stereoacuity as a useful tool in detecting monocular problems, advances in head X-ray, and, lastly, developments in objective assessment of the nerve head and central retinal artery.