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S Sokol

Publications and source records attributed to S Sokol.

At least 55 records · Page 3Linked to original sources
PubMed1981

Age-related changes in the latency of the visual evoked potential: influence of check size.

Pattern reversal visual evoked potentials were recorded from visually normal adults between 10 and 80 years of age. Two check sizes, 12 and 48 min, were used. The results showed that the latency of the first major positive component, P1, increased with age for both check sizes. This rate of increase was nearly twice as fast for 12 min checks. This difference is most likely a reflection of the differential effects of aging processes on the various spatial frequency channels in the human visual system.

Adolescent↗
PubMed1980

Changes in the binocular fixation patterns and the visually evoked potential in the treatment of esotropia with amblyopia.

Using the binocular fixation pattern (BFP) and the visually evoked potential (VEP), thirteen amblyopic patients with comitant, non-accommodative esotropia with an angle range up to 30 delta were studied before and during occlusion therapy. A graded BFP with a stronger preferred fixation could be used to diagnose amblyopia. The BFP, however, showed no significant change with therapy despite improvement in acuity. In contrast, the VEP amplitudes, initially reduced in amblyopia, increased significantly as the vision responded to patching. The VEP was useful in diagnosing strabismic amblyopia and giving a predictive range of acuities.

Amblyopia↗
PubMed1980

Pattern visual evoked potentials: their use in pediatric ophthalmology.

The purpose of this chapter has been to demonstrate that the VEP can be used as an objective measure of visual function in infants and young children. It provides the clinician with a quantifiable index of visual impairment, and indeed may be useful in predicting a reduction of subjective visual acuity before it is found on clinical examination. There is no doubt that such abnormalities as strabismus, cataracts, ptosis, and corneal opacities can be detected on clinical examination without the aid of VEPs; however, the VEP may determine, particularly in preverbal children, whether and to what extent that abnormality has caused an impairment in acuity. The assumption is made in the case of a monocular reduction in acuity that if VEP amplitudes from the two eyes are not equal, visual acuity is not equal. This is a valid assumption since there is a correlation between reduced visual acuity and VEP amplitudes in older children with amblyopia who give reliable subjective acuities. In addition to the detection and evaluation of acuity loss in infants and children, the VEP offers a way of monitoring the efficacy of occlusion therapy and CAM therapy. Also the VEP can be used to monitor the effects of corneal and lens opacities on visual development.

Adult↗
PubMed1980

Utility of the Arden grating test in glaucoma screening: high false-positive rate in normals over 50 years of age.

The Arden grating test was administered to 64 subjects between 6 and 82 years of age without ocular pathology, to 20 glaucoma patients, and to 21 ocular hypertensives. The results show an age effect, with significantly higher scores (lower sensitivity) in normal subjects over 50 years of age. In addition, there was no significant difference in performance between age-matched normals, glaucoma patients, and ocular hypertensives on the Arden gratings. The results show a high percentage of false-positives in older normal subjects. The Arden gratings should be used cautiously when one is testing patients over 50 years of age.

Adolescent↗
PubMed1979

Simultaneous electroretinograms and visually evoked potentials from adult amblyopes in response to a pattern stimulus.

Electroretinograms (ERGs) and visually evoked potentials (VEPs) were recorded simultaneously from each eye of three adult amblyopes. A spatially alternating checkerboard pattern stimulus of constant mean luminance was used to eliminate the effect of stray light on the ERG. The VEP was affected in the amblyopic eye of all subjects. In two subjects the VEP amplitude was reduced; in the third subject the amplitude was not attenuated, but the waveform of the VEP was markedly altered. Photopic ERGs recorded from the normal and amblyopic eye of each subject with an unpatterned flashing light were equal in amplitude. However, ERGs elicited by a patterned stimulus were affected in the amblyopic eye of all three subjects; the after-potential showed larger reductions in amplitude than the b-wave. These results suggest there may be some retinal involvement in human amblyopia.

Adult↗
PubMed1977

A corneal electrode for patterned stimulus electroretinography.

A corneal contact lens electrode employs a silver-coated hard contact lens placed onto a soft contact lens. The electrode is used without corneal anesthesia and has excellent optical characteristics that allow reliable and convenient recording of patterned electroretinograms.

Contact Lenses↗
PubMed1976

Pattern reversal visually evoked potentials in infants.

Visually evoked potentials (VEP) were recorded from infants two to six months of age using a checkerboard pattern reversal stimulus. By six months, infants produced the largest amplitude VEP to checks subtending visual angles of 7.5 or 15 minutes of arc, as do adults with 20/20 acuity. This finding indicates that by six months an infant's sensory capacity for a visual acuity of 20/20 is established.

Adult↗
PubMed1975

Use of methenamine hippurate in male infertility.

In sperm-freezing for infertility patients with low sperm counts, we found that semen containing high numbers of white blood cells, greater than 15 to 20 per high-power field, was both poor in quality and difficult to freeze. In examining these patients carefully, we found that many had smoldering prostatitis and some an overt history of prostatitis. We treated them with methenamine hippurate using various methods and found that by decreasing the white blood cell count in their semen, we could frequently improve the semen quality, particularly sperm motility, also achieve pregnancies in some cases.

Cell Count↗