Biomedical subjects
J D Trobe
Publications and source records attributed to J D Trobe.
Optic atrophy. Differential diagnosis by fundus observation alone.
In order to assess the contribution of fundus examination to the differential diagnosis of acuqired optic neuropathy, five ophthalmologists viewed 163 fundus stereophotographs of nine disease entities as "unknowns." Glaucoma, central retinal artery occlusion (CRAO), and ischemic optic neuropathy (ION) were diagnosed by at least one observer with an accuracy above 80%. The remaining conditions (optic neuritis; compressive, traumatic, and hereditary optic neuropathies) were correctly identified with less than 50% accuracy. Retinal arteriolar attenuation and sheathing were most helpful in differentiating CRAO and ION. Although pathologic disc cupping often identified glaucoma, it was also seen in 20% of eyes with optic atrophy not associated with glaucoma. Excavation was more profound in glaucoma than in nonglaucomatous optic atrophy, the latter demonstrating relatively greater neuroretinal rim pallor. In 6% of nonglaucomatous optic atrophy eyes, however, disc cupping was misdiagnosed as "glaucomatous." Only 11% of eyes with previously documented papillitis or ION left clues that allowed observers to identify preexisting disc swelling.
Nonglaucomatous excavation of the optic disc.
In order to test the hypothesis that glaucomatous and nonglaucomatous optic disc cupping can be distinguished ophthalmoscopically, three ophthalmologists experienced in assessing optic dics were asked to view fundus stereophotographs as "unknowns". Of 29 eyes with nonglaucomatous optic atrophy, 13 (44%) were misdiagnosed as showing glaucoma by at least one observer. Of four optic disc features specifically analyzed, neuroretinal rim pallor proved to be 94% specific for nonglaucomatous atrophy, while focal or diffuse obliteration of the neuroretinal rim was 87% specific for glaucoma. These two signs are the most useful in making the distinction. Thinning of the rim was more common in glaucoma than in nonglaucomatous atrophy, but was only 47% specific for glaucoma. Laminar dots were present in both types of excavation.
An evaluation of the accuracy of community-based perimetry.
We assessed the accuracy of five office-based perimetric technicians in the examination of 14 patients with prechiasmal and chiasmal defects unknown to them. A pre-test followed by two days of instruction and supervised practice; the technicians were then retested on the same patients (post-test). An independent evaluator scored their results. The identification of any field defect rose significantly (P = .039) from 69% in the pre-test to 95% in the post-test. The identification of the hemianopic configuration of a defect rose from 45% in the pre-test to 84% in the post-test (P = .11); initial identification of nasal steps was 77%, falling to 67% in the post-test. Adequate definition of extent, depth, and slope of defects was rare (5%) on the pre-test, but rose significantly (P = .032) to 57% on the post-test. The monitored patient examinations were essential for correcting recurrent flaws in technique. This study shows that such teaching efforts, including emphasis on identifying hemianopic defects, are necessary to raise visual field examination to the level of a consistently reliable diagnostic determinant.
The radiographic diagnosis of cavernous meningiomas and aneurysms with a review of the neurovascular anatomy of the cavernous sinus.
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Meningiomas and aneurysms of the cavernous sinus. Neuro-ophthalmologic features.
A series of 16 patients with unilateral ophthalmoplegia due to mass lesions of the cavernous sinus was analyzed; there were six cavernous meninglomas and nine intracavernous aneurysms. All meningiomas were characterized by painless, insidiously progressive partial nerve palsies, as were half of the aneurysms; the remaining aneurysm patients experienced acute painful episodes. Pharmacologic pupillary tests failed to confirm a coexisting Horner syndrome in the majority of cases with anisocoria. Although plain skull films were unremarkable or misinterpreted as normal, bone tomograms, computerized axial tomograms, radionuclide scans, and cerebral angiograms established the diagnosis in all cases. Because cavernous meningiomas show slow progression and are surgically inaccessible, craniotomy is advised only if the visual pathways or brain stem is compromised. Intractable pain appears to be the only distinct indication for intervention with cavernous aneurysms.
Dysthyroid optic neuropathy. Clinical profile and rationale for management.
Dysthyroid optic neuropathy (DON) was diagnosed in 36 eyes of 21 patients with progressive visual loss and congestive ophthalmopathy. Systemic features in the patients with DON did not differ from those reported for Graves' disease patients except that patients with DON were older (mean age, 61 years) and did not show female preponderance. Congestive symptoms always preceded visual loss, which was gradual in onset and bilateral in most patients but acute and asymmetrical in several. Presenting acuities were poorer than 20/60 in 50% of cases; central scotomas, sometimes combined with inferior depression, were the predominant field defects. Congestive signs were of moderate intensity without severe proptosis or exposure keratopathy. Bilateral and symmetrical ductional restriction was the most common motility disturbance. Oral corticosteroids were effective in restoring visual function in ten of 21 eyes treated. Many steroid-unresponsive eyes were improved promptly by supervoltage orbital irradiation or surgical decompression. In general, therapeutic intervention appeared to hasten recovery and improve visual outcome.
Quantitative perimetry in compressive optic neuropathy and optic neuritis.
The Goldmann perimetric defects in 20 cases of compressive optic neuropathy and 54 cases of optic neuritis were analyzed. While defects involving the papillomacular bundle were the rule in both compressive and neuritis cases, sparing of the fixational area occurred in 24% of neuritis eyes but in none of the eyes with compressive neuropathy. The most reliable differential perimetric sign was the presence of a hemianopic defect; at least one eye of 15 (75%) cases of compression showed such a defect, which was not found in any neuritis cases. The I2e was the largest kinetic isopter to demonstrate the hemianopic defect in a substantial proportion of cases. These defects were corroborated with sequential static presentation of the I2e to I4e stimuli to either side of the vertical meridan, and with similar techniques using 18/1,000 red test objects at the tangent screen.
Isolated oculomotor paralysis. The product of saccular and fusiform aneurysms of the basilar artery.
Isolated oculomotor paralysis was produced by an unsuspected saccular basilar aneurysm in one case and fusiform basilar aneurysm in another. The chronicity of symptoms and lack of pain were misleading features. The saccular basilar aneurysm, which has an untreated mortality of 50% to 80%, was visualized best with selective angiography and successfully clipped intracranially. The fusiform basilar aneurysm, part of a diffuse atherosclerotic ectasia of all basal intracranial arteries, indented and displaced the upper brain stem. A common ophthalmologic sign of posterior communicating aneurysms, oculomotor paralysis has not been documented frequently with basilar aneurysms.
The radiographic recognition of two clinically elusive mass lesions of the cavernous sinus: meningiomas and aneurysms.
Cavernous sinus syndromes secondary to chronic mass lesions, although a relatively rare cause of ophthalmoplegia, represent a distinct challenge in neuroradiologic diagnosis. Puzzling neuro-ophthalmologic signs and often subtle radiologic changes consistently lead to erroneous and delayed diagnoses as exemplified by a review of 20 patients; a correct clinical or radiographic diagnosis was initially not made in any individual.
Retinal degeneration without pigment alterations in progressive external ophthalmoplegia.
A 56-year-old black man had annular visual field defects and retinal electrophysiologic dysfunction with chronic progressive external ophthalmoplegia and no pigmentary abnormalities in the fundus. Because the association of retinal disease with neurodegenerative states has generally been based on the observation of pigmentary changes, the patient's fields were erroneously interpreted as the nerve fiber bundle defects of glaucoma.
Anti-herpes activity of adenine arabinoside monophosphate.
Adenine arabinoside monophosphate (Ara-AMP) demonstrated antiviral activity equivalent to adenine arabinoside (Ara-A) against herpesvirus Types 1 and 2 in tissue culture. Against established herpes virus Type 1 epithelial keratitis in rabbits, Ara-AMP 2 per cent was comparable in efficacy to Ara-A 3 per cent, and Ara-AMP 20 per cent was superior to Ara-A 3 per cent. These results are especially significant in that Ara-A's high solubility will permit (1) more concentrated formulations to be presented topically and (2) adequate absorption by parenteral routes with smaller fluid loads than required for Ara-A.
Atypical retinitis pigmentosa masquerading as a nerve fiber bundle lesion.
"Sector" or "asymmetric" retinitis pigmentosa was mistaken as bilateral nerve fiber bundle defects in a 56-year-old man for six years, leading to an unnecessary work-up for anterior visual pathway disease and to an incorrect diagnosis of low-tension glaucoma. Confusion arises because this variant may present with bilateral, superior, half-ring visual field defects that intersect the blindspots. These defects may be misplotted as typical arcuate Bjerrum's scotomas. The ophthalmoscopic changes that correspond to these visual field defects may be so subtle as to be overlooked. Fluorescein angiography helps bring out the retinal lesions, and moderately subnormal electroretinographic and dark adaptation studies are definitive.
Chromophobe adenoma presenting with a hemianopic temporal arcuate scotoma.
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Isolated homonymous hemianopia. A review of 104 cases.
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Recurrent corneal erosion.
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Dystrophic changes in the anterior cornea.
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