Biomedical subjects
Publications and source records attributed to T R Hedges.
A 65-year-old woman developed progressive, bilateral ophthalmoplegia, with thickened extraocular muscles on CT. One month later, a cardiac arrhythmia led to her death. Pathologically, the extraocular and skeletal muscles showed diffuse mononuclear cell inflammation, while the heart contained granulomatous myositis. This patient's syndrome of idiopathic, orbital myositis and giant cell myocarditis may be a distinct nosologic entity.
The use of press-on Fresnel prisms is described as a simple inexpensive technique to rehabilitate patients with homonymous hemianopsia. The optical principle of prismatic displacement from the blind to the seeing fields is detailed herein. Forty-one patients were evaluated over a 10 year period. Twenty per cent benefited from the prism. Many of those who found limited or little value from their use expressed appreciation that something had been tried in order to improve visual function. Those patients with good acuity and an otherwise normal neurological status are the best candidates. Proper motivation and instruction are essential.
A new catheter system was used in ten patients (16 infusions) for infusion of chemotherapeutic agents to the sites of malignant gliomas. Thirteen infusions to the supraophthalmic region were successful, as were three infusions to the posterior cerebral region. There were no complications after the infusions. A neurologic complication occurred in one patient in whom two successful supraophthalmic infusions were previously carried out. In this patient the guide wire separated during catheter placement into the posterior cerebral artery.
The Tolosa-Hunt syndrome (THS), a steroid-responsive painful ophthalmoplegia secondary to idiopathic granulomatous inflammation, historically has been categorized as a diagnosis of exclusion because of its nonspecific radiologic presentation. Five patients who satisfied the anatomic and clinical criteria of this syndrome underwent high-resolution CT of the orbital apex/cavernous sinus region. Two patients were diagnosed as having orbital apex pseudotumor, two as having cavernous sinus inflammation, and one as having a cavernous sinus epidermoid by the characteristic CT and clinical findings. Follow-up studies while the patients were asymptomatic demonstrated complete resolution of the CT abnormalities in four patients and clinical improvement in all five patients. Our data suggest that orbital apex pseudotumor and granulomatous inflammation of the cavernous sinus have similar clinical features and should be considered as part of the spectrum of THS. With the advent of high-resolution CT, THS may now be a diagnosis of inclusion. Symptomatic improvement after steroid therapy is an essential but not absolute proof of the syndrome, since lesions such as lymphomas may also respond to steroids. Resolution of the soft-tissue inflammation of CT is an additional criterion for diagnosis.
Ocular involvement with acute Epstein-Barr virus infection is usually limited to a transient follicular conjunctivitis, although other lesions have been reported. Chronic Epstein-Barr virus infection has recently gained attention, but ocular manifestations have not been emphasized. We describe three patients with chronic infection with prominent ocular involvement. Bilateral uveitis was noted in all patients, ranging from an anterior uveitis that was responsive to steroids to a severe panuveitis with vitritis, cataract, optic disc swelling, and macular edema. In one patient, topical acyclovir ointment resulted in a substantial decrease in the inflammatory reaction when added to systemic acyclovir therapy. Another patient displayed a keratitis that resolved with topical steroid therapy. Cataract and vitreous surgery were also beneficial in the management of these patients.
We analyzed the clinical features of symptomatic posterior cerebral artery (PCA) stenosis in 6 patients selected from 15 patients with angiographically documented PCA atherostenosis occurring during a 7-year period. Transient ischemic attacks (TIAs) were the major presentation in 5 patients. A homonymous visual field defect was present in 2 patients. TIA symptoms were predominantly visual or sensory, or both. The most common visual symptom was difficulty seeing to one side. One patient saw flashing lights. Sensory spells were always paresthetic, usually involving the arm and hand and occasionally the face and leg. Three patients had visual and sensory spells together. Two patients with a visual field defect had calcarine infarcts found by computed tomography. All patients were treated with warfarin. During follow-up (4 months to 4 years), no patient had a new stroke in the PCA territory, and only one continued to have TIAs. PCA atherostenosis is rarer then PCA embolic occlusion. In contrast to those with PCA embolism, our patients with PCA atherostenosis had more TIAs and fewer infarcts. The clinical features of PCA stenosis--preponderance of visual and sensory TIAs--distinguish this vascular lesion from stenosis of the middle cerebral artery.
To clarify the clinical features and mechanism of infarction in the posterior cerebral artery territory, we investigated 35 consecutive patients who presented with homonymous visual field defects and occipital infarction documented by computed tomography. Cerebral angiographic findings in 23 patients, and the clinical features of rare transient ischemic attacks and maximal deficit occurring at stroke onset, were consistent with embolism of the posterior cerebral artery. Visual field defects were the only neurological abnormality in 17 patients; the remainder had additional findings. Three patients had a major brainstem stroke. Stroke in the posterior cerebral artery territory was found in a heterogeneous group of patients, although embolism was the most common stroke mechanism. Several distinct patient groups were identified: cardiac source embolism (10 patients), vertebrobasilar atheroma with local embolism (6), migraine (5), systemic illness with presumed coagulopathy (3), and "unknown source embolism" after negative cardiac investigation (11 patients). During follow-up, 26 patients had no further neurological events (the majority on anticoagulation or antiplatelet treatment), 3 suffered new strokes, and 6 died.
Observation of the retinal nerve fiber layer with red-free light is an important means of evaluating optic nerve integrity. Many investigators have attempted to increase the usefulness of the technique by improving photographic procedures. Most reports comparing various parameters neither indicate the method of comparison nor give quantitative measure of the improvement gained with different films, filters, cameras, or processing procedures. We have compared in a masked fashion the parameters most recently recommended in the literature. Twelve trained observers compared 12 masked pairs of nerve fiber layer photos taken from the same eye in the same manner on two cameras and preferred those taken with a Canon CF-60Z camera 69% of the time and those taken with a Zeiss FF-111 17% of the time (this difference was statistically significant, P less than 0.01). Fourteen observers compared 14 pairs of photographs and judged Panatomic-X film to be superior to Plus-X film 51% of the time and both films to be of the same quality 25% of the time (this difference was also significant P less than 0.05). Fifteen observers compared 12 pairs and preferred the Standard SE-40 blue filter 2:1 over the green Spectrotech 540 filter. This difference was not statistically significant, and the preference was found to be dependent on fundus pigmentation and clarity of the media. The blue filter gave better contrast for the nerve fiber layer in patients with lightly pigmented fundi, and use of the green filter resulted in less light scatter in patients with ocular media opacities.
Acute retinal arterial occlusive events in the eye are generally easily recognized and the association with embolic material, often from ulcerative lesion of the ipsilateral carotid vessels, usually can be established by noninvasive imaging techniques. In contrast, chronic retinal and choroidal circulatory impairments from ophthalmic artery insufficiency is usually due to high-grade, hemodynamically-significant carotid occlusive disease which can be difficult to recognize because of the diverse clinical features and presentations. We present herein the experience of the senior author (LEM) in the diagnosis and management of these complex cases.
The usefulness of computerized tomography (CT scanning) in managing orbital cellulitis is analyzed in six cases. What appears as orbital abscess on CT scan may not be confirmed at surgery. Careful clinical evaluation and responsiveness to antibiotic therapy are most important in determining the need for surgical intervention.
We investigated a number of image processing techniques for enhancing the retinal nerve fiber layer (NFL) in fundus photographs taken with red-free light. Wedge-type defects within the NFL were enhanced best by contrast enhancement algorithms such as histogram modification and extremum sharpening. Narrow, slitlike NFL defects can be enhanced by directional enhancement techniques. Normal NFL features were enhanced best by high-pass filtering techniques such as homomorphic filtering and adaptive enhancement. The enhanced normal NFL may be useful in the analysis of diffuse NFL loss. All of these successful enhancements of normal and defective features indicate that enhancing fundus photographs with digital image processing techniques should facilitate early detection of optic nerve damage from glaucoma and other diseases.
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One hundred patients with ocular occlusive vascular disease were studied by intravenous digital subtraction angiography (IV DSA). In 17 patients with transient monocular blindness, 65% showed ipsilateral carotid atheroma. The degree of carotid stenosis was greater than 70% in eight of the 17 patients. Severe unilateral or bilateral stenosis was demonstrated in 70% of ten patients with chronic retinal artery obstruction, ie, venous stasis retinopathy or orbital hypoxia. An ipsilateral carotid artery source of emboli or substantial degree of stenosis was documented in 50% of 48 patients with acute retinal artery obstruction. Little or no carotid disease was found in 72% of 25 patients with retinal vein obstruction. The greatest value of IV DSA is in the management of patients with transient monocular blindness.
A patient with a large pituitary adenoma and visual field loss showed no significant change 6 weeks after transsphenoidal operation, but marked and abrupt improvement occurred at 10 weeks. The implications of this delayed improvement are discussed.
Optic nerve dysfunction occurred several weeks after traumatic carotid-cavernous fistula developed in a 21-year-old man. Vision was completely restored after the fistula was closed with an intra-arterial detachable balloon. By carefully monitoring visual function in patients with traumatic carotid-cavernous fistulas, delayed optic neuropathy can be recognized and treated successfully.
Legionnaires' disease can exhibit protean extrapulmonary manifestations. Pericardial involvement is rare and has been described in three case reports. A patient is described with Legionnaires' disease and pericardial and ocular involvement, an entity that has not been reported previously. This patient was successfully treated with intravenous erythromycin with resolution of his pericardial effusion and ophthalmologic findings.
Computed tomography (CT) scan is a valuable adjunct in the differential diagnosis and management of retinoblastoma. Thirty-one of 33 retinoblastoma patients studied with high resolution computed tomography had intraocular calcification demonstrable in at least one eye. Over 80% of tumors showed evidence of calcification on CT scan. The degree of calcification appeared to depend upon tumor size; only small tumors were devoid of calcification. The amount and distribution of calcification was similar on both histological and CT review. In patients under three years of age in whom a retinoblastoma is suspected, the presence of calcification on CT scan is virtually diagnostic of retinoblastoma; patients with leukocoria without calcification on CT probably have a simulating lesion.
Ophthalmic complications from moyamoya disease, or multiple progressive intracranial arterial occlusion syndrome, have rarely been reported. This case report describes a patient with this syndrome who developed acute retinal artery occlusion.