The ice test versus the rest test in myasthenia gravis.

OBJECTIVE: To compare the ice test with the rest test in subjects with myasthenic and nonmyasthenic ptosis. DESIGN: Randomized, noninterventional trial. PARTICIPANTS: (1) Ten subjects with ptosis from previously undiagnosed myasthenia gravis. (2) Fifteen subjects with nonmyasthenic ptosis. METHODS: Application of ice compared with rest. MAIN OUTCOME MEASURES: Improvement in eyelid elevation in millimeters after the application of a surgical glove filled with ice or cotton. RESULTS: In myasthenic subjects, the median improvement of ptosis with the rest test was 2 mm and with the ice test was 4.5 mm. The difference between the rest and ice tests is significant (P: < 0.001). There was no improvement in ptosis in nonmyasthenic subjects with either test. CONCLUSION: In myasthenic ptosis, improvement in eyelid elevation after the ice test is in part caused by rest. The ice test significantly improves ptosis more than rest alone does.

Low diagnostic yield with second biopsies in suspected giant cell arteritis.

OBJECTIVES: The clinical diagnosis of giant cell arteritis may be confirmed with a biopsy of the superficial temporal artery. Because of "skip lesions," a histologic diagnosis of giant cell arteritis may be missed with a unilateral biopsy. The authors report a study that investigates whether a biopsy of the contralateral superficial temporal artery provides any additional information for confirmation of a diagnosis of giant cell arteritis. METHODS: Available medical records of 91 consecutive patients who underwent bilateral superficial temporal artery biopsy procedures were reviewed. Information that was abstracted included sequence of biopsy procedures, length specimens, and histologic diagnosis. Microslides from all biopsy specimens were retrieved and reexamined in a masked fashion by the ocular pathologist (RCE) who had made the original diagnoses. RESULTS: Seventy-two bilateral simultaneous superficial temporal artery biopsies and 19 bilateral sequential biopsies were performed. The mean length of biopsy specimens was 23 mm, and the mean length of the total artery removed from each patient was 33 mm. The pathologist's original diagnosis and the diagnosis at reexamination were in 100% agreement. In 90 (99%) of the 91 patients, the histologic diagnoses in the left and right superficial temporal arteries were the same. This is a concordance rate of 98.9% (38 of 39 positive biopsy results) among the positive biopsy results. CONCLUSION: There is a low yield of information from a second temporal artery biopsy in patients with suspected giant cell arteritis. This suggests that patients who present to the ophthalmologist with possible giant cell arteritis will, in most cases, have a similar diagnosis on both temporal artery biopsies if the specimens are adequate.

Unilateral lid retraction during pregnancy.

A 32-year-old woman noted left lid retraction during pregnancy. Examination revealed unilateral enophthalmos without symptoms of diplopia or sinus disease. Orbital imaging showed characteristic features of the silent sinus syndrome, which were confirmed intraoperatively. The clinical and imaging attributes of this syndrome are discussed, including possible mechanisms of disease development. Management strategies are summarized. A brief discussion of the differential diagnosis of enophthalmos is also included.

Progressive visual loss and ophthalmoplegia.

A 51-year-old woman with hyperthyroidism presented with a 4-week history of bilateral progressive visual loss despite treatment with oral prednisone. Her visual function improved after bilateral orbital decompression. The indications for and advantages and disadvantages of radiation therapy and orbital decompression in TAO are discussed. The management of intraocular pressure, strabismus, and lid abnormalities in TAO is also addressed.

Chiasmopathy?

A 57-year-old man presented with progressive visual loss in both eyes, bitemporal field defect, and a history of poor nutrition, alcohol abuse, and excessive cigar smoking. Magnetic resonance imaging was normal. The visual acuity and field defect improved with supplementation with vitamins and reduction of alcohol and tobacco consumption. A diagnosis of toxic optic neuropathy was made. The authors discuss the differential diagnosis of bitemporal/pseudobitemporal field defects and the diagnosis and treatment of toxic optic neuropathy.

Not so slowly progressive visual loss.

A 51-year-old man presented with bilateral progressive visual loss during a 2-month period. Visual acuity was 20/60 in both eyes with bilateral constricted visual fields. Funduscopy revealed bilateral disk pallor and arteriolar attenuation. His vision declined rapidly during the next 2 weeks. Investigations showed a positive cerebrospinal fluid Venereal Disease Research Laboratory test (1:8). A diagnosis of neurosyphilis was made, and treatment was started with high-dose intravenous and intramuscular penicillin.

Refractive changes during 72-hour exposure to high altitude after refractive surgery.

PURPOSE: The authors prospectively analyzed refractive and pachymetric parameters during exposure to high altitude after radial keratotomy (RK) and photorefractive keratectomy (PRK). METHODS: The authors measured manifest and cycloplegic refraction, keratometry, computed video keratography, and central and peripheral pachymetry in six subjects who have undergone RK (11 eyes), six who have undergone PRK (12 eyes), and nine with myopia (17 eyes) at sea level and on three consecutive days at 14,100 feet. All measurements were repeated 1 week after subjects returned to sea level. RESULTS: Subjects who have undergone RK demonstrated a significant and progressive increase in spherical equivalence (+0.30 +/- 0.50 diopters on day 1 and +1.52 +/- 1.01 diopters on day 3; P < 0.001) and a decrease in keratometry values during exposure to altitude when compared with control subjects with myopia. Healthy subjects and those who have had PRK demonstrated no significant change in refractive error. Pachymetry measurements demonstrated significant peripheral corneal thickening in all three groups (RK, P < 0.004; PRK, P < 0.007; control subjects, P = 0.0006) by day 3 at high altitude. Refraction, keratometry, and pachymetry returned to baseline (P = 1.000) after return to sea level. CONCLUSIONS: Seventy-two-hour exposure to high altitude in subjects who have had RK induces a significant, progressive, and reversible hyperopic shift in refraction with corresponding video keratographic and keratometric changes. The authors hypothesize that the high-altitude hypoxic environment causes increased corneal hydration in the area of the RK incisions, which may lead to central corneal flattening and a hyperopic shift in refractive error. Subjects who have had PRK and those with myopia are not susceptible to this refractive shift. The authors' RK data suggest that the time since surgery and the amount of surgery are related to the degree of hyperopic shift during altitude exposure.