Electrical cataracts: a case report and review of the literature.

A case report of electrically-induced cataracts and a review of the literature is presented. Awareness of the possibility of this complication and screening of high-risk patients is stressed. The majority of cases respond well to surgery, but final visual acuity may be decreased secondary to retinal or optic nerve injury caused by the electrical current.

Effects of ethyl alcohol on VECP.

Previous studies have demonstrated that ethyl alcohol ingestion affects the clinically recorded visually evoked cortical potential (VECP). However these studies have not related the possible relevance of such alcohol-induced VECP changes to visual performance. We studied the flash and pattern-reversal monopolar VECP recorded at the occiput before and after alcohol ingestion and compared the recordings with psychophysical parameters (e.g. contrast sensitivity) also measured before and after alcohol intake. Results are presented, and the potential usefulness of VECP alterations in predicting alcohol-induced effects on visual performance is evaluated. We found no clear, consistent effect of blood alcohol levels ranging from 0.05% to 0.15% on the parameters tested.

Gas chromatographic analysis of lens monosaccharides.

Gas-liquid chromatography was employed to determine free monosaccharides in human, rat, and South American rodent Octodon degu lenses. In addition to D-glucose, D-fructose, sorbitol and myo-inositol, which were previously known to be components of lens tissue, glycerol, erythritol, threitol, ribitol, xylitol, and mannitol were also detected in the lenses of these three species. The concentrations in lenses of these three species were in the following ranges: glycerol 1.2 to 40 mumol/gm wet tissue; myo-inositol 4 to 25; and glucose, fructose, and remaining alditols 0.01 to 1.4/mumol/gm. The method is described and its applicability to analyses of free monosaccharides in other animal tissues is discussed.

Proptosis secondary to subdural hematoma.

A subdural hematoma extending into the orbit through a fracture of the sphenoid bone appeared as unilateral proptosis with no neurologic abnormalities. Repeated percutaneous needle aspirations of the orbital portion of this mass provided only temporary relief of proptosis, but decompressed the intracranial portion of the hematoma adequately for prevention of neurologic manifestations. Ultrasonography correctly diagnosed the nature of the lesion and identified the bony dehiscence. Computed tomographic (CT) evaluation suggesting that a tumor might be present led to the performance of curative neurosurgery. Even when seemingly trivial, head trauma must be considered along with congenital, developmental, and neoplastic causes as a potential cause of intracranial cyst formation that can produce proptosis.

Bilateral choroidal osteomas associated with fatal systemic illness.

An 11-year-old black boy complained of intermittent occipital headaches with nausea and projectile vomiting. Previous skin and lung biopsy specimens were interpreted as histiocytosis X. Cranial computed tomographic scanning disclosed a mass lesion in the region of the choroid plexus of the left lateral ventricle. This was surgically removed but proved nondiagnostic despite extensive histologic examination. An ophthalmologic evaluation showed discrete, elevated, yellow-white choroidal tumors in both maculas. The ophthalmoscopic appearance, as well as ultrasonography and computed tomography, led to the diagnosis of choroidal osteomas.

Arden grating test in evaluating "early" posterior subcapsular cataracts.

Patients with "early" posterior subcapsular (PSC) cataracts often complain of severe visual impairment, despite maintenance of relatively good Snellen acuity. The Arden grating test of contrast sensitivity provides a simple method of evaluating visual function in a manner more nearly approximating the real visual world. This test often reveals profound loss of contrast sensitivity in patients with early PSC cataracts who maintain relatively good acuity (20/40 or better) on Snellen's test. Examination of 122 such eyes revealed wide variations in contrast sensitivity, with Arden scores showing better correlation with subjective complaints than with Snellen acuity levels. While Snellen's test measures only one end of the spatial modulation transfer function (MTF), the Arden test plates provide an overall picture of MTF and help us to better understand the effect of PSC cataracts on visual function.

Blue field entoptoscopy and VER in preoperative cataract evaluation.

Blue field entoptoscopy (BFE) has been described as an effective method for evaluating macular function in patients with dense cataracts. We evaluated 150 preoperative cataract patients with BFE, and found the commercially-available instrument (MIRA BFE 100) to be accurate in patients with 20/400 or better preoperative acuity. There was a high percentage of false negative BFE results in patients with dense cataracts, and light flash VER testing was found to correlate better with attainable postoperative acuity in these patients.

Cataracts and riboflavin deficiency.

Lenticular reduced glutathione, diminished in all forms fo human cataract, requires flavin adenine dinucleotide as a coenzyme for glutathione reductase. Deficiency of riboflavin, a precursor of flavin adenine dinucleotide, has been believed by some to be associated with cataract formation. We evaluated the riboflavin nutritional status of healthy young adults, presenile and senile cataract patients, and young and older patients with clear lenses. We found no evidence of an association between riboflavin deficiency and early cataract formation, either idiopathic or secondary. Older cataract patients had more riboflavin deficiency. An absence of riboflavin deficiency was found in our older patients with clear lenses. The degree of riboflavin deficiency encountered in the general population does not appear to be cataractogenic.

Vitelliform macular lesions.

Two patients with vitelliform macular lesions, normal EOG Arden ratios, and no family history of Best's vitelliform dystrophy are presented. Their findings are compared with those in 10 similar reported cases, and a common, nongenetic aetiology is suggested for all. The several names given to this identical fundus picture by different authors are examined and are seen to be inappropriate. A common, descriptive terminology for all such lesions is suggested.

The effect of diabetes mellitus and diabetic therapy on cataract formation.

A study of diabetic and nondiabetic subjects was performed to evaluate the possible association of diabetes mellitus with cataract formation. Parameters investigated included cataract incidence and type model of diabetic therapy, degree of diabetic control, duration of glucose-6-phosphate dehydrogenase (G-6-PD) activity. Diabetes mellitus was found to be correlated with posterior subcapsular cataract formation, as was duration of diabetic disease. Race, degree of metabolic control, and age of onset of disease did not appear to be correlated with cataract formation. Oral hypoglycemic agent therapy was significantly associated with posterior subcapsular cataract formation. The African variant of G-6-PD deficiency appeared to protect against cataract formation in diabetic patients. The most important overall factor in cataractogenesis proved to be age. Posterior subcapsular cataracts were associated with corticosteroid therapy, presence of diabetes mellitus, and oral hypoglycemic agent therapy.

Wiskott-Aldrich syndrome: cellular impairments and their implication for carrier detection.

A family in which two male siblings were affected with Wiskott-Aldrich syndrome (WAS) was studied using G-6-PD isoenzymes as an X-linked marker in order to investigate the nature of cellular abnormalities. Isolated peripheral blood cell types from the doubly heterozygous mother of the affected males seemingly failed to express the G-6-PD allele in cis position with the WAS allele while her cultured skin fibroblasts expressed both G-6-PD alleles. Additionally, a histogram analysis of platelet size revealed a single population of abnormally small platelets in the affected propositus, whereas the heterozygous mother had no appreciable small platelet subpopulation. In vitro culture of hemopoietic progenitor cells of the heterozygous mother showed that the majority of progenitor cells did not express the WAS allele. However, a small number of cells expressing the G-6-PD type linked with the WAS allele were detected. The proportion of the latter progenitors was significantly higher among more primitive progenitors (those giving rise to later appearing colonies). This observation suggests that selection against cells expressing the Wiskott-Aldrich defect takes place in the hemopoietic system of the heterozygous female and offers a possible means of carrier detection in some women. Linkage studies in this family revealed one example of probable recombination between the loci for WAS and G-6-PD among three informative subjects, suggesting that these two loci may not be closely linked on the X-chromosome.

Effect of corticosteroids on cataract formation.

While the cataractogenic effects of corticosteroids are beyond dispute, disagreement exists concerning effects of total dose, intensity of dose, and duration of administration on cataract formation. We studied 106 adult male patients matched for age, race, and socioeconomic status. We compared posterior subcapsular (PSC) cataract formation among those with (39) and without (67) a history of systemic corticosteroid therapy. Difference in incidence of PSC opacities among patients with and without a history of corticosteroid therapy was statistically significant. However, no statistically significant correlation was found between PSC opacities and total steroid dose, weekly dose (intensity), duration of dose, or age of patient. Our findings agree with some recent literature that suggests the most important factor in steroid-induced PSC cataract formation may be variability in individual susceptibility to side effects of corticosteroids. We suggest abandoning the concept of a "safe" dose.

Presenile cataract formation and decreased activity of galactosemic enzymes.

One hundred forty-seven patients, 144 with advanced cataract formation, had determinations of erythrocyte galactokinase and galactose-1-phosphate uridyl transferase performed. Significant reduction (more than 2 SDs) of one of these enzymes was found in 47.4% of patients 50 years old or less with presenile "idiopathic" bilateral cataracts, 7.1% of other patients with cataracts aged 50 years or less, and 3.8% of patients with cataracts aged 51 years or more. The differences between the group with presenile idiopathic cataracts and the other groups were statistically highly significant (P less than .001). Patients with reduced activity of galactokinase or galactose-1-phosphate uridyl transferase (presumed heterozygotes) compose about 1% of the general population, appear to be more susceptible to idiopathic presenile cataract formation, and may be more prone to secondary cataract formation after a variety of lenticular insults. Dietary restriction of milk and milk products may prevent or delay cataract formation in these individuals.

Effect of age on Arden grating acuity.

Arden grating test scores were obtained for 100 normal subjects under standardised testing conditions. While previously published ranges of interocular conguity were corroborated, a significant increase in test scores with increasing age was noted. This effect of age has not been previously reported. Physiological considerations suggest that such age dependency might have been expected. It is suggested that ranges of normal values be established for each of several age groups.

Comparison of Snellen acuity, VER acuity, and Arden grating scores in macular and optic nerve diseases.

Patients with various macular and optic nerve abnormalities underwent Snellen acuity, transient VER acuity, and Arden grating testing. Snellen acuity was the coarsest of the 3 evaluations, generally falling after Arden scores and VER acuity had already undergone significant degradation. The Arden gratings appeared to be the most sensitive of the 3 tests, equalling VER performance in optic nerve diseases and surpassing it in macular diseases. Variations in results between the different tests are generally understandable if one considers the functions tested by each and the anatomical derangements caused by the diseases in question. The Arden grating test appears to be an excellent and sensitive screening test for central visual disturbances.