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Biomedical subjects

L D Pickwell

Publications and source records attributed to L D Pickwell.

33 records · Page 2Linked to original sources
PubMed1980

A model for sensory adaptations of the visual system in squint.

Sensory adaptations to squint are considered in the light of present knowledge of the visual sensory system. A model to assist our understanding of the clinical presentation of sensory adaptation is proposed. Suppression and abnormal correspondence are considered as anomalies of different parts of the sensory system, and the interplay of these adaptations is reviewed.

Adaptation, Ocular↗
PubMed1980

Unequal retinal illuminance and the binoculus.

An investigation was carried out in the relationship between the position of the binoculus and the depth (transmittance) of a monocular filter. The method used relied on changes in motor function and the linearity of the relationship found by previous workers, who used purely visual techniques, was confirmed. Some anomalous results were found which remain unexplained.

Eye Movements↗
PubMed1979

Prevalence and management of divergence excess.

The prevalence of divergence excess was assessed from the records of 250 consecutive patients attending a binocular-vision clinic. The 67 cases in the sample showing divergence excess were subdivided into the following groups: (1) secondary to operations for esotropia (8 cases); (2) anisometropic amblyopes (14 cases); (3) basic (14 cases); (4) convergence weakness (13 cases); (5) divergence excess (18 cases). Treatment methods placed heavy emphasis on physiological diplopia. Of the 18 in the divergence excess category, 14 began treatment, 10 showed a satisfactory outcome, two achieved some improvement, and two discontinued treatment on their own. Divergence excess seems to respond well to nonsurgical treatment.

Adult↗
PubMed1979

After-image transfer--evaluation of short-term treatment.

The records of treatment by the after-image transfer method of 21 children, mainly with strabismus amblyopia, were examined to evaluate the acuity improvement in the short term. There was no significant improvement in 15 cases. In several other patients, an immediate response to the after-image method occurred, but these patients' binocular vision and acuity had deteriorated following previous improvement achieved by other orthoptic methods.

Adolescent↗
PubMed1979

The foveal reflex in amblyopia.

The relative brightness of the foveal reflex between amblyopic eyes and their fellows was examined. Differences in reflex appearances were found in some patients but not in others. Equal appearance of the foveal reflexes does not eliminate the possibility of amblyopia, nor is there a difference in appearance related to the degree of amblyopia.

Adolescent↗
PubMed1976

Eye movements in heterophoria.

Reference is made to earlier reports by the author in which versional recovery eye movements were observed during the cover test in the non-occluded eye in case of heterophoria. This provided support for Hering's Law, although the magnitude of the versional movement did not relate to the degree of heterophoria. Recent studies of eye movements during the cover test on very small heterophorias have suggested there is a threshold value below which these versional recovery movements are absent, and that is presence depends on such factors as the size of the phoria, the degree of ocular motor dominance and patient concentration.

Eye Movements↗