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Biomedical subjects

G H Bresnick

Publications and source records attributed to G H Bresnick.

At least 19 recordsLinked to original sources
PubMed1992

Characterization of the electroretinographic scotopic B-wave amplitude in diabetic and normal subjects.

The intensity-response function of the scotopic b-wave of the electroretinogram may be a useful device for monitoring patients with retinal disease. Three models were evaluated that describe this function in 152 patients with diabetic retinopathy of varying severity and in 40 nondiabetic comparison subjects. The models considered were the Naka-Rushton equation fit to all 21 data points collected, the Naka-Rushton equation fit to the data points below the "second limb" of the function, and a log-linear fit only to data at the nine lowest intensities. In addition, the b-wave amplitude at each intensity tested was evaluated individually. Model parameters and amplitude measurements were compared with respect to (1) their ability to distinguish diabetic from nondiabetic subjects determined from the area under the receiver operating characteristic curve and (2) their correlation with retinopathic severity, graded in a standard fashion in fundus photographs. When all the parameters of each model were used in combination, there were no significant differences among the models with either evaluation criterion. Furthermore, b-wave amplitudes at midrange intensities (near -2.2 log cd-sec/m2) did approximately as well as any model.

Adolescent↗
PubMed1991

Lenses of diabetic patients "yellow" at an accelerated rate similar to older normals.

The authors used a psychophysical method to measure lens transmission of young, type I diabetic patients and normal controls. The results from normal controls agreed with previously published reports of decreasing lens transmission with age, and those from diabetic subjects suggested that lenses of young, type I diabetic patients age or "yellow" at an accelerated rate that was similar to that of normal controls over the age of 60 yr. The rate of accelerated lens density that occurs per year with the duration of diabetes is similar to the rate of accelerated lens density that occurs per year with patient age over 60 yr. A possible molecular explanation for the accelerated lens yellowing in both populations is discussed. Both diabetic individuals and the older normal populations have elevated plasma glucose levels and therefore may have accelerated glycosylation of lens proteins which causes increased lens yellowing.

Adult↗
PubMed1989

Autosomal dominantly inherited macular dystrophy with preferential short-wavelength sensitive cone involvement.

We found an apparently inherited tritan-like color vision defect in five members of a family, spanning three generations. The defect was associated with mild macular pigmentary changes, poor foveolar reflexes, or slightly reduced visual acuity in four of the affected individuals. The inheritance pattern appeared to be autosomal dominant. Results of various color vision tests indicated preferential involvement of the short-wavelength sensitive cone system, with relative preservation of the middle- and long-wavelength sensitive cone systems. Both anomaloscope testing with larger (8-degree) fields and short-wavelength sensitive electroretinography indicated some short-wavelength sensitive cone system involvement beyond the central macula in the three affected individuals on whom testing was performed. The condition appeared to be a familial macular dystrophy with preferential short-wavelength sensitive cone involvement. The abnormal macular findings and mild reduction in visual acuity distinguish this condition from congenital tritanopia; the normal optic disks distinguish it from autosomal dominant optic atrophy.

Adolescent↗
PubMed1989

Spinocerebellar ataxia, hypogonadotropic hypogonadism, and choroidal dystrophy (Boucher-Neuhäuser syndrome)

We describe two families (including one previously reported) in which cerebellar or spinocerebellar ataxia, hypogonadotropic hypogonadism, and choroidal dystrophy result from abnormal function of an autosomal recessive gene. Review of the literature adds one other family with this disorder. These three examples confirm the existence of this traid as a specific, pleiotropic, single-gene syndrome. Careful ophthalmologic evaluation of patients with ataxia and hypogonadotropic hypogonadism may identify additional cases.

Adult↗
PubMed1988

Acute posterior multifocal placoid pigment epitheliopathy associated with cerebral vasculitis.

Acute multifocal posterior placoid pigment epitheliopathy (APMPPE) is an unusual self-limited retinal disorder that has been associated with various systemic complications. To our knowledge, three prior cases associated with cerebral vasculitis have been described. This article describes a patient with APMPPE and angiographically documented cerebral vasculitis who was notable because of (a) the presence of two different cerebral ischemic events, occurring 1 month apart, and (b) the long latency (3 months) between the onset of ocular symptoms and the second cerebral ischemic event. Recognition of the association between APMPPE and cerebral vasculitis may permit early treatment of CNS involvement and prevention of morbidity.

Adult↗
PubMed1987

Temporal aspects of the electroretinogram in diabetic retinopathy.

We measured the temporal aspects of several components of the electroretinogram in 72 patients with diabetes and 29 control subjects. The measurements consisted of the implicit times of the a wave and oscillatory potentials elicited by a bright-flash stimulus and the implicit time of the b wave in response to a 30-Hz flickering light. The a wave and first three oscillatory potential nodes were significantly delayed in the patients with diabetes compared with the controls; among the diabetics, a significant increase in the delay of the second and third nodes occurred as a function of increasing retinopathy severity. Similarly, the 30-Hz flicker implicit times (with and without a background light) were significantly delayed in patients with diabetes, and the magnitude of the delay increased with increasing retinopathy severity. The correlations of 30-Hz flicker implicit times with retinopathy severity were significant for retinopathy level graded in color fundus photographs as well as for retinal capillary nonperfusion and leakage graded in fluorescein angiograms. A comparison of 30-Hz flicker implicit times in 15 patients with one eye treated with panretinal laser photocoagulation and the other eye untreated (treatment was randomly assigned) showed a significant delay in the treated eyes compared with the untreated eyes (paired eye comparison). This suggests that panretinal laser photocoagulation induces a further delay in the b-wave implicit times of eyes treated for diabetic retinopathy.

Adult↗
PubMed1987

Predicting progression to severe proliferative diabetic retinopathy.

The longer-term progression of retinopathy was observed in a previously described group of 85 diabetic patients enrolled in the Early Treatment Diabetic Retinopathy Study. The probability of progression to severe retinopathy was significantly greater for eyes with the following baseline characteristics: greater overall retinopathy severity, higher fluorescein leakage, higher capillary nonperfusion, and lower electroretinographic oscillatory potential amplitudes. The summed amplitudes of the oscillatory potentials, the overall severity of retinopathy, and the severity of fluorescein angiographic leakage were found to be independent predictors of progression to severe proliferative retinopathy in a regression model; capillary nonperfusion was not found to predict progression independently when fluorescein leakage was included in the model. Probability curves based on the regression model can be used to support clinical decisions concerning when to perform panretinal laser photocoagulation and how often to follow up patients with less than severe proliferative diabetic retinopathy.

Adult↗
PubMed1987

Oscillatory potential amplitudes. Relation to severity of diabetic retinopathy.

The oscillatory potentials of the electroretinogram and other visual function tests were evaluated in a group of 174 diabetic and 54 control subjects. Retinopathy severity in diabetic patients was measured in color fundus photographs and fluorescein angiograms. The summed amplitudes of the oscillatory potentials were significantly lower in diabetic compared with control subjects, and the amplitudes decreased progressively as the retinopathy severity increased. Among diabetic patients, a significant correlation was found between the oscillatory potentials and the other visual function tests; lower amplitudes were associated with lower visual field and visual acuity scores and higher Farnsworth-Munsell 100-hue error scores. Stepwise regression analysis showed that the most important predictors of oscillatory potential amplitudes were retinopathy level, fluorescein leakage, and age; capillary nonperfusion did not add to the predictive power of the model when fluorescein leakage was included.

Adult↗
PubMed1986

Diabetic macular edema. A review.

Diabetic macular edema can be classified into a focal variety, characterized by focal leakage from microaneurysms, often with accumulation of extravascular lipoprotein in a circinate pattern around the focal leakage, and a diffuse variety, with diffuse leakage from retinal vessels often accompanied by cystoid macular changes. Laser photocoagulation is directed at microaneurysms for focal leakage and is applied in a grid pattern for diffuse leakage. Several prospective randomized clinical trials have shown that laser-treated eyes fare better than untreated eyes: there is a higher rate of modest visual improvement and a lower rate of visual deterioration in eyes treated with laser photocoagulation. In patients with diabetic macular edema, especially the diffuse variety, systemic factors also may play a pathogenic role. Fluid retention and hypertension due to cardiovascular and renal disease exacerbate retinal capillary leakage. Correction of systemic abnormalities (reduced blood pressure, diuresis) may reduce macular edema and should be included as part of the total management of patients with diabetic macular edema.

Clinical Trials as Topic↗
PubMed1979

Retinal wrinkling and macular heterotopia in diabetic retinopathy.

Retinal wrinkling of the posterior pole was studied in 40 eyes from 31 patients with diabetic retinopathy. Vitreoretinal traction was thought to produce the wrinkling in 32 of the eyes, in 13 of which macular heterotopia also developed, presumably from the same tractional forces. Epiretinal membrane formation was the apparent causal factor producing retinal wrinkling in six eyes and postphotocoagulation chorioretinal scarring in two eyes, in none of which macular heterotopia developed. Retinal wrinkling alone was associated with only mild or no visual acuity loss. Macular heterotopia was associated with more severe loss of visual acuity and with other visual symptoms. Displacement of retinal vessels was an important clue to the diagnosis of macular heterotopia.

Adult↗
PubMed1979

A method for recording vitreoretinal relationships.

A method for recording vitreoretinal relationships is described. The system includes designations for the extent and height of posterior hyaloid detachment and for sites of abnormal vitreoretinal adhesions. The method may be used for preoperative evaluation of eyes prior to vitrectomy surgery or for the follow-up of patients with vitreoretinal disease.

Eye Diseases↗
PubMed1979

Retinal branch vessel occlusion in acute intermittent porphyria.

Three patients with acute intermittent porphyria were noted to have retinal branch vessel occlusion. Branch "vein" occlusion, segmental optic atrophy, and soft exudate were the most common ocular manifestation. Two patients had labile elevated hypertension. When patients present with retinal branch vessel occlusion and a constellation of bizarre symptoms that might include hypertension, abdominal pain, acute psychotic behavior and/or cutaneous photosensitivity, the diagnosis of acute intermittent porphyria should be considered.

Abdomen↗
PubMed1978

Postvitrectomy keratopathy.

Twenty-six of 75 eyes undergoing pars plana vitrectomy developed significant corneal complications requiring treatment. Slow or nonhealing epithelial abrasions, recurrent corneal erosion, and microcystoid and striate keratitis were among the most frequent problems. Significant predisposing factors included diabetes, surgical trauma such as epithelial debridement and prolonged operative time, aphakia, and postoperative glaucoma or hyphema. Corneal complications may be minimized with careful preoperative and operative precautions.

Adult↗
PubMed1977

Clinicopathologic correlations in diabetic retinopathy. II. Clinical and histologic appearances of retinal capillary microaneurysms.

One eye of a 21-year-old patient with proliferative diabetic retinopathy was available for clinicopathologic correlation. The fluorescent spots in a fluorescein angiogram were correlated with the changes in color fundus photographs and with the corresponding histologic findings in a trypsin digest preparation of the retina. A round, regular fluorescent spot was the most reliable diagnostic indicator of retinal capillary microaneurysms, although some microaneurysms appeared as irregular fluorescent spots, tiny fluorescent spots, or dark silhouettes with or without fluorescent halos. Very large fluorescent spots correlated with very large irregular pouches that may represent intraretinal neovascularization. Fluorescein angiography was considerably more sensitive than color fundus photography for the detection of retinal capillary microaneurysms.

Adult↗