Biomedical subjects
Publications and source records attributed to S Lessell.
We evaluated two patients with tuberous sclerosis (TS) and cataracts. In one, the cataract had been noted at an early age. In the second, it was noted at her first ophthalmic examination, age 31. Review of the literature indicates that although in some cases, cataract is attributable to local ocular disease, it may be a rare manifestation of TS.
OBJECTIVE: To describe patients with orbital apex masses involving the optic nerve who enjoyed spontaneous improvement in visual function without therapy. METHODS: A retrospective chart review of cases in an academic neuro-ophthalmology practice identified three cases of tumorous compression of the optic nerve in which there was spontaneous improvement in visual function. Each patient had undergone a full neuro-ophthalmologic evaluation, followed up with serial imaging. RESULTS: The first patient initially had a visual acuity of 2/200 and central visual field defects. Over a 4-year period, her visual acuity improved to 20/40 and her visual field expanded centrally. The second patient initially had a visual acuity of 20/40 and a cecocentral visual field defect. After a 4-year follow-up, her visual acuity had improved to 20/15 and her cecocentral defect had shrunk. The third patient had an initial visual acuity of 20/25, an afferent pupillary defect, and optic atrophy. Over a 2-year period she developed a paracentral scotoma and her visual acuity worsened to 20/30. In the next 2 years her visual acuity improved to 20/10 and her visual field normalized. CONCLUSIONS: In exceptional instances, visual dysfunction from tumorous compression of the optic nerve in the orbital apex may spontaneously improve. Clinicians who use the natural history of visual loss in differential diagnosis should be aware that spontaneous remission is compatible with the presence of tumor.
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AIMS: The efficacy of an artificial intelligence technique, neural network analysis, was examined in differentiating two optic neuropathies with overlapping clinical profiles-idiopathic optic neuritis (ON) and non-arteritic anterior ischaemic optic neuropathy (AION). METHODS: A neural network was trained with data from 116 patients with 'gold standard' diagnoses of ON or AION. It was then tested with data from 128 patients with presumed ON or AION, and the correlation of the network's diagnosis with that of expert clinicians tabulated. RESULTS: The network agreed with the clinicians on 97.8% (88 of 90) of the patients with presumed ON and 94.7% (36 of 38) of the patients with presumed AION. Youth, female sex, better initial acuity, a central scotoma, subsequent improvement in acuity, or progressive disease biased the network towards a diagnosis of ON, while advanced age, male sex, presence of hypertension, poor initial acuity, an altitudinal field defect, disc oedema, or less improvement in acuity biased the network towards a diagnosis of AION. CONCLUSION: Neural network analysis is a useful technique for classification of optic neuropathies, particularly where there is overlap of clinical findings.
We report two cases in which heteronymous, altitudinal visual field defects resulted in loss of fusion and transient overlap of preserved hemifields. This phenomenon resulted in complaints of diplopia similar to that described as "hemifield" slide previously described by temporal hemianopsias. These cases illustrate that generalized loss of fusion, and not the particular type of hemianopic field defect, is responsible for the symptoms known as hemifield slide.
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PURPOSE: Cupping of the optic disc, a characteristic sign of glaucoma, has been anecdotally described in association with compressive optic neuropathy. The aim of this study is to perform a masked, controlled, and quantitative measurement of the optic disc cup to determine if compressive lesions of the afferent visual pathway were associated with increased cupping. METHODS: The ratio of cup area:disc area of 29 patients with intracranial lesions impinging on the optic nerves and the chiasm (14 with pituitary adenomas, 7 with meningiomas, 6 with craniopharyngiomas, and 2 with aneurysms) was compared with those of 20 age-matched control subjects. The areal ratios were derived planimetrically from hand-drawn images of magnified stereophotographs. Patients were divided into three groups based on the degree of laterality of visual compromise. Uninvolved eyes served as an internal control for patients with unilateral disease. RESULTS: The median ratio of cup area:disc area was 0.37 for all eyes with visual compromise (n = 51) and 0.10 for control eyes, which was statistically significant (P = 0.0001). The median intereye difference in the ratio of cup area:disc area was 0.13 for patients with unilateral lesions and 0.04 for control subjects. This difference also was statistically significant (P = 0.0001). CONCLUSIONS: The finding of intereye asymmetry in patients with unilateral optic nerve compression is convincing evidence that the enlarged cup is an acquired feature. Several types of compressive lesions of the anterior visual pathway can be associated with increased cupping of the optic disc in the absence of increased intraocular pressure.
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PURPOSE: To describe a visual complication of optic nerve sheath fenestration. METHODS: Case review of two patients who underwent seemingly uncomplicated optic nerve sheath fenestration. FINDINGS: Both patients had a surgical complication that resulted in significant depression of their temporal visual field and development of a wedge-shaped region of subretinal pigmentation in the nasal fundus. CONCLUSIONS: Both patients had choroidal infarctions as a complication of optic nerve sheath fenestration. Choroidal infarction should be considered in cases of unexpected loss of visual field after this type of surgery, although the funduscopic signs that assist in making the diagnosis may not be evident for several weeks after surgery.
BACKGROUND: The proper management of neurogenic visual loss after blunt head trauma is controversial. Non-treatment, corticosteroids, and surgical decompression of the optic canal are all currently considered to be reasonable alternatives. The goal of this study was to identify factors affecting improvement in patients treated with canal decompression. METHODS: A retrospective analysis of 31 cases in which transethmoidal decompression of the optic canal had been performed for neurogenic visual loss after closed head trauma was conducted. Each patient was alert and free of injury to the globe when evaluated before surgery. Surgery was performed within 6 days of injury, and all were given perioperative steroids. RESULTS: Visual acuity improved in 22 (71%) patients, with 6 (19%) regaining visual acuity of 20/40 or better. The mean improvement from preoperative visual deficit was 42.0% +/- 6.6%, with a median improvement of 45.2%. Both univariate and multivariate analysis suggested that vision improved more in patients who were younger than 40 years of age than in patients who were 40 years of age or older. Interval between injury and surgery, preoperative visual acuity, and the presence of optic canal fracture did not affect outcome. CONCLUSION: Any future randomized trials of therapy should stratify patients based on age. Enrollment of patients with no light perception or who experienced delay between injury and treatment may be reasonably considered.
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Minor head trauma precipitated oculomotor nerve palsies in two patients who subsequently were discovered to have ipsilateral posterior communicating artery aneurysms. A history of minor trauma should not dissuade investigation for underlying causes of oculomotor nerve palsy, including intracranial aneurysm.
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Neuro-ophthalmic manifestations are important in multiple sclerosis. Optic neuritis is a frequent harbinger of the disease, and is characterized by subacute painful visual loss, with disproportionate loss of color and contrast sensitivity, central or cecocentral scotoma, and an afferent pupillary defect. Visual recovery is the rule, but tests have been developed to detect most cases of recovered optic neuritis. Intraocular inflammation has come to be recognized as a frequent accompaniment of multiple sclerosis. Because of the predilection of multiple sclerosis for the infratentorial white matter, defects in eye movement control are common, particularly internuclear ophthalmoplegias and nystagmus.
Tobacco amblyopia, once an important cause of bilateral optic neuropathy, has become so rare in the United States that some investigators doubt its existence. However, we treated two men who appeared to have this disorder. These two patients demonstrate that tobacco amblyopia can develop without malnutrition, alcoholism, or disordered vitamin B12 metabolism. Both patients recovered, one with cessation of smoking and the other with intramuscular administration of hydroxocobalamin despite continued smoking.