Daniel M. Jacobson

Enlargement of the Blind Spot Caused by Papilledema

Blind spot enlargement in papilledema has been attributed to either mechanical disruption of the integrity of the peripapillary percipient elements by the swollen optic disk or to the Stiles-Crawford effect. We investigated the possibility that blind spot enlargement in papilledema is caused, at least in part, by a refractive scotoma due to peripapillary hyperopia. We reduced the enlarged blind spot in a patient with focal peripapillary hyperopia, without papilledema, to near normal size by using progressively stronger plus lenses. Similarly, with the addition of plus sphere, we reduced the size of the blind spot in five of six patients with papilledema, but in none of our normal subjects.Blind spot enlargement in papilledema has been attributed to either mechanical disruption of the integrity of the peripapillary percipient elements by the swollen optic disk or to the Stiles-Crawford effect. We investigated the possibility that blind spot enlargement in papilledema is caused, at least in part, by a refractive scotoma due to peripapillary hyperopia. We reduced the enlarged blind spot in a patient with focal peripapillary hyperopia, without papilledema, to near normal size by using progressively stronger plus lenses. Similarly, with the addition of plus sphere, we reduced the size of the blind spot in five of six patients with papilledema, but in none of our normal subjects.

Maternal orbital hematoma associated with labor

We examined two women with orbital hematomas that occurred during labor. Both women developed sudden diplopia, proptosis, and orbital pain. The location of the hematoma was confirmed by orbital echography and computed tomography. The patients were observed without surgical intervention. Neither patient developed clinical or echographic signs of compressive optic neuropathy. Clinical resolution occurred during the following two weeks. Serial standardized orbital echographic examinations documented resolution of the hematomas.

X -linked Progressive Cone Dystrophy

The authors evaluated nine affected males and six female carriers from a four-generation family with X-linked cone dystrophy. As the affected males grew older, visual acuity deteriorated, central scotomas deepened, and macular changes became more prominent. There was granularity of the macula in younger individuals and bulls eye lesions and central geographic atrophy of the retinal pigment epithelium (RPE) in the older subjects. The retinas of some affected males had a bronze-green tapetal-like sheen. Color vision was impaired in all affected males and resembled an acquired type II defect (Verriest classification). One younger subject had paradoxical pupillary constriction to darkness. Visual-evoked potential (VEP) latencies were prolonged in some affected males, suggesting that photoreceptor degeneration caused transsynaptic degeneration of ganglion cells. All female carriers had visual acuities of 20/30 or better, but some showed mild ophthalmoscopic changes and abnormalities of color vision, electroretinograms (ERGs), and VEPs.

Unilateral third nerve palsy caused by Guillain-Barré Syndrome

AbstractBackground: Highly asymmetric clinical signs in a patient suggest the need for caution in making the diagnosis of Guillain-Barré Syndome (GBS).n Methods: Case report and literature review. We present a case of strictly unilateral left third cranial nerve palsy in a patient with GBS, review other highly asymmetrical cranial nerve palsies previously reported in this condition, and suggest an appropriate alternative differential diagnosis.n Conclusion: Unilateral third cranial nerve palsy is an exceptionally rare manifestation of GBS, expanding the spectrum of clinical signs and neuraxis involvement that may be seen in the condition.

Nontraumatic subperiosteal orbital hemorrhage during labor

Abstract The following two letters address an article that appeared in the May 2001 issue of the Journal: Atalla ML, McNab AA, Sullivan TJ, Sloan B. Nontraumatic Subperiosteal Orbital Hemorrhage. ( Ophthalmology 2001;108;183–9 )

Compression of the prechiasmatic optic nerve produces a junctional scotoma: Author reply

PURPOSEnTo demonstrate the clinical-radiologic correlation between a junctional scotoma and a focal lesion compressing the prechiasmatic segment of the distal optic nerve.nnnMETHODSnCase report involving a man with a pituitary adenoma. Clinical correlation was determined by reviewing visual field evaluations and magnetic resonance images.nnnRESULTSnThe tumor compressed the prechiasmatic segment of the distal optic nerve but not the optic chiasm, producing a junctional scotoma documented by Goldmann and automated perimetry. The visual field defect resolved after neurosurgical decompression of the anterior visual pathway.nnnCONCLUSIONSnA junctional scotoma can be caused by focal as well as large and diffuse lesions injuring the anterior visual pathway, specifically at the junction of the optic nerve and chiasm. This finding supports the existence of Wilbrand fibers.