Biomedical subjects

J S Sunness

Publications and source records attributed to J S Sunness.

25 records · Page 2Linked to original sources

PubMed1990

Retinal pigment epithelial tears through the fovea with preservation of good visual acuity.

We describe two patients with spontaneous retinal pigment epithelial tears through the fovea who have maintained at least 20/40 visual acuity for 1 year and 3 years following the rip. Both patients had long-standing serous detachments of the retinal pigment epithelium associated with age-related macular degeneration prior to the development of the tear. Each tear was at least five disc areas in size and centered on the fovea. Foveal fixation was documented despite the presumed absence of pigment epithelium. This observation suggests either that there may be remaining or redundant pigment epithelium or that pigment epithelium directly beneath the central macula is not required for maintenance of 20/40 visual acuity.

Female↗

PubMed1989

Diminished foveal sensitivity may predict the development of advanced age-related macular degeneration.

Visual function testing was performed on one eye with drusen from each of 18 elderly patients in 1984. Eleven patients had advanced age-related macular degeneration (AMD) in the fellow eye, and seven had only bilateral drusen. These patients were all followed prospectively (median, 45 months), at which time one eye had a new vessel membrane, three eyes had pigment epithelial detachments, and one eye had geographic atrophy. Only two of these five eyes had AMD-related visual loss in the fellow eye in 1984. The degree of loss of foveal dark-adapted sensitivity in 1984 predicted which patients developed advanced AMD with 100% sensitivity and 92% specificity. The presence of high-risk drusen characteristics in 1984 predicted the development of advanced AMD with 100% sensitivity but only 55% specificity. For this small group of patients, foveal dark-adapted sensitivity loss was an excellent predictor of the subsequent development of advanced AMD in eyes with drusen. A prospective study of a large group of patients with drusen is being undertaken to validate this finding.

Aged↗

PubMed1988

Retinal sensitivity over drusen and nondrusen areas. A study using fundus perimetry.

Elderly patients with drusen and good visual acuity have a decrease in dark-adapted retinal sensitivity in the central retina. We used the fundus camera stimulator to determine whether this sensitivity loss is caused directly by the presence of drusen. We measured retinal sensitivity over drusen and in drusen-free areas in eight patients with drusen and age-related macular degeneration (AMD). There was no significant difference in sensitivity between drusen and nondrusen areas in each patient. The sensitivity loss seen in patients with drusen thus seems to reflect a more diffuse disease of the retina and retinal pigment epithelium and is not a direct effect of drusen. More marked sensitivity losses are found in even small areas of more advanced AMD changes, suggesting that a large focal loss in retinal sensitivity may be an indicator of developing AMD changes.

Aged↗

PubMed1986

Flicker electroretinogram in retinitis pigmentosa.

Electroretinograms (ERGs) were recorded as a function of flicker frequency from 5 to 50 Hz for 14 retinitis pigmentosa (RP) patients, 12 normal subjects and 1 rod monochromat. Data were analyzed by measuring the angular position of the response maximum, i.e. the phase, as a function of pulse-train frequency. Flicker ERGs obtained from the RP patients showed non-linear, frequency-dependent phase shifts when compared to the normal data. These phase shifts were simulated in a normal observer by attenuating the stimulus luminance by 1 log unit. However, the shape of the waveforms recorded from the normal differed markedly from those recorded from the RP patients. The differences, but not the ratios of the times-to-peak of the positive and negative ERG wavelets were longer in the RP patients than in the normal. These data suggest that the temporal anomalies in the RP flicker ERG are most likely due to changes in the amplitudes and time constants of the ERG components, and not simply to a reduced quantum catch or photoreceptor loss.

Adolescent↗

PubMed1986

Focal electro-oculogram in age-related macular degeneration.

Age-related macular degeneration (AMD) is an important cause of vision loss among the elderly. Because patients with early subretinal neovascular membranes due to AMD can be treated by laser photocoagulation it becomes critical to find tests which can detect early changes. Inasmuch as AMD involves the retinal pigment epithelium, one might expect the electro-oculogram (EOG) to be sensitive to AMD pathology, but the ganzfeld EOG has been found to be normal in most cases. We designed a focal EOG apparatus to try to emphasize the contribution of the central retina, where AMD is found, to the EOG. Seventeen patients with various stages of drusen and AMD were tested and compared with normals. The focal EOG did not separate the AMD patients from the normals, nor did it give different distributions for the various subgroups of AMD. The focal EOG, like the ganzfeld EOG, is not a sensitive test for AMD.

Aged↗

PubMed1985

Peripheral retinal function in age-related macular degeneration.

Aging changes are seen histopathologically outside the central retina, but have not been correlated with the presence of age-related macular degeneration (AMD). We studied 21 patients with drusen and AMD to see if peripheral retinal function changes are correlated with changes in the central retina. Electrooculogram Arden ratios were normal. Intensity-response analysis of dark-adapted electroretinogram b-waves and analysis of flicker electroretinograms were normal except for a small sensitivity loss presumed to reflect aging and lens yellowing. There was no difference between patients' severely involved AMD eye and their fellow eye with only drusen. Static perimetry showed sensitivity loss in the central 20 degrees, but normal thresholds peripheral to this. These results suggest that retinal function abnormalities in AMD are confined to the central retina, and the small age-related peripheral changes found do not correlate with the degree of AMD.

Age Factors↗

PubMedDate not supplied

The pregnant woman's eye.

The effects of pregnancy on the eye fall into three categories. Nonpathological physiologic changes in pressures, corneal sensitivity and thickness, and visual function can occur. Pathologic conditions reported to develop during pregnancy include central serous chorioretinopathy, hypertensive and vascular disorders, and uveal melanoma. Pregnancy also can affect pre-existing ocular conditions, such as diabetic retinopathy, tumors, and a variety of immunological disorders and can have beneficial effects on such pre-existing conditions as glaucoma. This review covers ocular disorders in these three categories, and summarizes the systemic changes of pregnancy and the effects of ocular medications on the fetus.

Eye Diseases↗