Search PubMed⌕ Search

Biomedical subjects

A Jampolsky

Publications and source records attributed to A Jampolsky.

At least 37 records · Page 2Linked to original sources
PubMed1984

Predicting visual resolution from detection thresholds.

Visual acuity is one of the most frequent health measures and is central to vision assessment in schools, industry, aviation, drivers' licensing, and ocular health examinations. There is a need for a rapid, simple, and interpretation-free measure of visual acuity which is amenable to automated and objective assessment. This study shows that a rapid (15 s) and simple contrast threshold measure for a 5 min arc spot correlates highly (r = 0.75) with letter acuity in 360 clinic patients. Assessments by optometrist and technician correlated highly (r = 0.88) as did repeated measures by the same examiner (r = 0.85). The instrumentation appears to be well suited for rapid, automated, and interpretation-free assessment of visual acuity and for visual acuity screening.

Humans↗
PubMed1983

Overcorrecting minus lens therapy for treatment of intermittent exotropia.

The purpose of this paper is to determine the value of overcorrecting minus lenses in treating children with intermittent exotropia. The aim with this therapy is to secure an increase in the quality of fusion and to induce a quantitative decrease in the angle of strabismus. Thirty-five children were treated with 2.00 to 4.00 diopters of overcorrecting minus lenses for a median of 18 months duration. Of these, 46% had an improved quality of fusion during therapy; 26% had an improved quality of fusion and also had a quantitative decrease in their angle of deviation; and 28% had an inadequate improvement in their quality of fusion and decrease in the angle of their deviation with this therapy. Two children went from intermittent exotropia to esotropia while wearing their minus lenses--both had high accommodative-convergence/accommodation ratios (11.5 delta/1D and 10.7 delta/1D). Seventy percent of good responders who were followed for at least 1 year after discontinuing the therapy maintained a qualitative or quantitative improvement in their intermittent exotropia.

Child↗
PubMed1982

Diagnostic injection of Xylocaine into extraocular muscles.

In situations where it is unclear which extraocular muscle is causing anomalous eye movement or to what extent one of two muscles is responsible, temporary paralysis of the muscle with Xylocaine may provide the answer. The procedure is to inject 0.2 to 0.5 cc 2% Xylocaine directly into the muscle using electromyography (EMG) for precise localization, a technique similar to that of therapeutic injections of botulinum toxin (Oculinum). The procedure is especially useful for Duane's syndrome, superior oblique palsy, and other situations where abnormal muscle insertions or innervations make diagnosis of the muscle responsible for an eye movement anomaly difficult and surgery unpredictable.

Adolescent↗
PubMed1982

Effects of an anticholinergic drug, benactyzine hyrochloride, on vision and vision performance.

Benactyzine is an anticholinergic agent which has been used in past years in psychiatry, but is little used today. It has central and peripheral anticholinergic effects, and when administered intramuscularly, it has a rapid onset of action. This may make it useful as an antidote for organophosphate poisoning, in spite of side-effects such as deficits of short term memory, concentration, and attention. As an anticholinergic drug it could also be expected to produce vision changes by its action on the intraocular musculature controlling the pupil and lens accommodation. We tested the drug on six volunteer subjects to establish the visual side-effects of intramuscular administration. We found that it reduced static and dynamic visual acuity, increased pupil size, reduced amplitude of accommodation and contrast sensitivity, while having little or no effect on glare recovery, color vision, intraocular pressure, stereoacuity, oculomotor tracking, and distance heterophoria. Benactyzine produced reductions in visual performance for up to 3 h and had the greatest effects on functions which have significant cognitive components. The present results suggest that the drug is unsuitable for treatment for oganophosphate poisoning when continuous performance is required, although a definitive test of ths suggestion would require that performance should be tested when benactyzine and the organophosphate of interest were combined.

Adult↗
PubMed1981

Extraocular muscle forces in normal human subjects.

Actively developed horizontal muscle forces and tissue stiffnesses were measured in 29 normal orthophoric volunteer subjects (18 to 33 years old) by means of noninvasive length-tension forceps. Mean active fixation force developed at 50 deg extreme gaze was 26% greater for the medial rectus (74.8 gm) than for the lateral rectus (59.1 gm). The variation of maximum active force among individuals was 2:1 (48 to 103 gm). These muscles developed up to 25% of their maximum active force out of their field of action. Active (counter) hysteresis force differences of over 10 gm were measured between nasal and temporal gaze directions. This study suggests that a muscle which develops a maximum active force of less than 45 gm would be suspect as paretic. Variations from the normal pattern of reciprocal innervation, reflected in the graded active force of individual muscle contraction, may help in understanding some types of oculomotor pathology. The mean tissue stiffness-restraining movement of the globe in the nasal direction (1.05 gm/deg) is 11% greater than in the temporal direction (0.94 gm/deg). This is consistent with a stronger medial rectus balanced by a greater load. Variation of stiffness of 2:1 was observed among individuals; 0.8 to 1.7 gm/deg pulling nasally and 0.77 to 1.2 gm/deg temporally. Passive hysteresis and viscous force differences of over 10 gm were observed between the passive forced pull and normal spring-return of the eye. Large stiffnesses may be normal if balanced by large active forces. Abrupt changes of the length-tension curve indicate the magnitude and location of restrictions.

Adolescent↗
PubMed1979

Lateral incomitancy in intermittent exotropia: cause and surgical therapy.

A hypothesis, previously proposed, of tight medial rectus muscles in conjunction with tight lateral rectus muscles associated with exodeviations as a cause of lateral incomitancy in intermittent exotropia is supported by clinical management. Three patients with these findings underwent bilateral medial rectus and lateral rectus recessions by means of the adjustable rectus recession technique. Primary position alignment was achieved, and rotations were balanced with the alleviation of the lateral incomitancy. The lateral rectus muscles were recessed an amount more than usual in order to compensate for the recession of the medial rectus muscles.

Adolescent↗
PubMed1979

An adjustable transposition procedure for abduction deficiences.

We used an adjustable transposition procedure in two cases of horizontal abduction deficiency (one of lateral rectus palsy and one of Duane syndrome with marked co-contraction). Primary position balanced alignment and maximum balanced rotations were obtained without inducing vertical deviation as the result of the transposition. The vertical force vectors were neutralized by the self-adjusting nature of the vertical rectus union. The procedure allowed for both intraoperative and postoperative adjustment of the result.

Child↗
PubMed1979

Current techniques of adjustable strabismus surgery.

Adjustable strabismus surgical procedures provide the opportunity to reposition a surgically altered muscle position, which is often necessary for nonaverage cases of strabismus correction. The usual surgical procedure is extended into the postoperative period (same hospitalization) so that the surgeon may satisfactorily monitor the total end result (by cover test and rotations) at the time of adjustment. Adjustable techniques should be considered whenever a desired goal is unlikely to be reached in one surgical session. Recent technical improvements allow satisfactory globe position control during the adjustment stage for ease of recession or resection adjustment. Globe stabilization is attained during surgery and the postoperative adjustment by means of a scleral loop handle, placed near the corneoscleral limbus. Millimeters of adjustment are easily estimated by means of a sliding suture knot technique.

Humans↗
PubMed1978

Intentional surgical overcorrection of acquired esotropia.

Fifty-eight patients with surgically treated acquired nonaccommodative esotropia were studied retrospectively, to ascertain what immediate surgical result gives the best chance for a postoperative bifoveal fusional result. Of the cases that were initially overcorrected (exodeviations), approximately two thirds were fusing six months or more after surgery. Of the cases that were initially aligned (orthophoric) or undercorrected (esodeviations), only one third were fusing after the same period. These results suggest that intentional surgical overcorrection of cases of acquired nonaccommodative esotropia that have a good fusional potential (ie, equal vision) does appear to be a desirable goal for the immediate postoperative period.

Adolescent↗
PubMed1978

The O'Connor cinch revisited.

The modified O'Connor cinch operation is a useful, but little used, adjustable resection operation. For increased understanding of its shortening and adjustment characteristics, a standard cinch was performed in animals and patients with strabismus. Animal studies showed that, as each strand of the cinch was removed, a small, relatively equal release of the cinch effect occurred. Measurement of the shortening obtained in patients with strabismus showed a consistent resection effect of about 4 mm. Review of 17 cases in which the cinch was used as part of the surgical treatment showed the technique to be adjustable by reducing the overcorrection in 6 cases. Ten to 20 prism dioptres of reduction in the deviation was obtained with adjustment of the cinch on the first postoperative day. All 17 cases had satisfactory adjustment. The largest residual deviation was 12 prism dioptres.

Adolescent↗
PubMed1977

A clinically useful eye movement recording system.

A simple, stable, and relatively calibration-free eye movement recording system for clinical application is described. This limbal sensing device makes use of a standard trial-lens clip that can be attached to the patient's spectacles, allowing easy and quick addition of lens or prism power. Horizontal eye movements or positions can be recorded with an accuracy of better than 1 degree over a 50-degree range; the linear range of the device is approximately 30 degrees.

California↗
PubMed1976

Mangement of infantile esotropia.

We evaluated the management of infantile esotropia-constant, alternating esotropia before 6 months of age-in 34 children. Planned one-state surgery for satisfactory mechanical alignment was highly predicatable (79 to 84%), and was obtained at any age. Stable bifoveal motor fusion was also obtained but was more frequent with alignment before 2 years of age. The use of postsurgical spectacle orthoptics (minus lenses or prisms, or both) increased the incidence of bifoveal fusion. Surgery alone resulted in bifoveal fusion in 6% of the cases, whereas an overall incidence of 33% bifoveal fusion resulted after the use of postsurgical spectacle orthoptics by some patients. Of those receiving postsurgical spectacle orthoptics, 53% obtained bifoveal fusion. This study demonstrated a correlation between the incidence of secondary A patterns (after surgery for V esotropia) and the amount of horizontal muscle surgery done in combination with bilateral inferior oblique muscle myectomies.

Age Factors↗
PubMed1975

Pseudoparalysis caused by anomalous insertion of superior rectus muscle.

Congential ectopia of the insertion of the superior rectus muscle to the superior border of the lateral rectus muscle was seen in a 4-year-old child. In all respects, this condition mimicked congenital superior rectus palsy. The resultant large hypotropla was completely corrected by repositioning the superior rectus to its normal anatomic position.

Child, Preschool↗
PubMed1975

Strabismus and pseudostrabismus with retrolental fibroplasia.

Three patients with temporal displacement of the macular secondary to retrolental fibroplasia had true strabismus in associations with amblyopia and pseudostrabismus related to a large, positive angle kappa. In one case, a headturn associated with the neutral point of nystagmus was also a presenting problem. Ocular deviation was measured by the light reflex test and the prism cover test, with particular attention paid to adequate cosmetic alignment. Large amounts of prism placed before the fixating eye resulted in loss of visual acuity, while eyes placed in a parallel position by surgical means may not appear to be straight. Thus, surgery can result in parallel ocular alignment while prismatic therapy may be required to center the pupillary light reflex and to provide satisfactory cosmetic appearance.

Accommodation, Ocular↗