Painful oculomotor nerve palsy due to dural-cavernous sinus shunt.

Two patients presented with painful unilateral oculomotor nerve palsies without evidence of ocular congestion or hypoxia. They were initially thought to have posterior communicating or distal internal carotid aneurysms, but had, in fact, dural-cavernous sinus shunts, draining posteriorly into the inferior petrosal sinus. One patient later developed a moderately severe congestive ophthalmopathy, and repeated selective carotid arteriograms showed that the shunt was now draining anteriorly into the superior ophthalmic vein. In the other patient, the oculomotor nerve palsy resolved without the development of any further signs. These observations support the concept that dural-cavernous sinus shunts produce symptoms that are dependent on the direction of drainage from the shunt. It is clear that the direction of drainage can change and that thrombosis of the posterior cavernous sinus determines the direction of drainage. The exact mechanism of the cranial neuropathy is, however, unknown.

The retinal manifestations of mitochondrial myopathy. A study of 22 cases.

In a series of 61 patients with the morphologic and histochemical features of mitochondrial myopathy, 22 (36%) had pigmentary retinopathy. Three patterns of retinopathy were identified. Eighteen patients had a "salt and pepper" type of retinal appearance, which was usually associated with good visual function. Two had many features of retinitis pigmentosa, and two others showed generalized loss, or atrophy, of the retinal pigment epithelium and choriocapillaris. These last four patients had markedly reduced visual acuities, with optic atrophy and attenuated retinal vessels. Electroretinography and electro-oculography were performed in 11 patients. Both rod and cone mediated electroretinographic functions were subnormal in eight patients, while only cone mediated functions were depressed in the remaining three. The electro-oculographic changes were variable.

Scleral canal size and optic nerve head drusen.

From projected optic disk photographs we measured the size of the scleral canal in two samples of emmetropic patients: one of patients with unilateral pseudopapilledema and drusen and the other of the general normal population. Measurements on the non-drusen-containing optic disk of patients with unilateral drusen were taken to reflect the scleral canal size of the fellow, affected eye. For both trained (t = 6.642) and untrained (t = 4.274) observers, the average diameters of the non-drusen-containing optic disks of patients with unilateral drusen were significantly smaller than those of the optic disks of normal patients (P = .0005, one-tailed independent t-test). The association of a small scleral canal with vascular anomalies, frequently noted in optic disks of patients with drusen, indicates a mesodermal dysgenesis of the optic nerve head.

Ophthalmodynamometry revisited.

Ophthalmodynamometry was performed on 100 patients with amaurosis fugax or transient cerebral ischemic attacks to determine its value in identifying significant (over 50%) carotid stenosis as verified by angiography. Of three criteria for an abnormal result of ophthalmodynamometry a corrected systolic pressure of 70 mm Hg or less had the highest sensitivity (95%) and overall accuracy (88%) in identifying significant carotid stenosis. However, with the use of all three criteria, only one of which had to be met in an individual case, ophthalmodynamometry still identified significant carotid obstruction with 80% sensitivity, 78% accuracy and a false-positive rate of 25%. Thus, ophthalmodynamometry appears to be just as useful as any of the more expensive and complicated noninvasive tests for carotid stenosis currently available.

Computed tomographic diagnosis of buried drusen of the optic nerve head.

We present three patients with optic nerve drusen. On the basis of headaches, transient obscurations of vision, or visual field loss the patients underwent orbital computed tomographic (CT) scanning. This procedure confirmed the presence of buried drusen in the four optic discs that had yielded poor ophthalmoscopic and angiographic evidence of drusen; drusen had been observed in the other two discs. The indications for CT scanning in the presence of visible or buried drusen of the optic nerve head are discussed.