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Biomedical subjects

J N Trachtman

Publications and source records attributed to J N Trachtman.

10 recordsLinked to original sources
PubMed1987

Biofeedback of accommodation to reduce myopia: a review.

Since the first report in 1970 of biofeedback to train voluntary control of accommodation, the use of biofeedback to train accommodation has progressed from basic research demonstrations to the clinical treatment of myopia. The initial reports showed that voluntary control of accommodation could be trained easily and accurately. The next series of investigations were into the efficacy of the technique for training low (less than 1.00 D), functional myopes. The research showed that functional myopia could be reduced with biofeedback training of accommodation. Finally, the technique has expanded into training for a wide range of myopes from children to senior citizens. The results demonstrate the effectiveness of biofeedback in reducing myopia by training voluntary control of accommodation.

Accommodation, Ocular↗
PubMed1981

Biofeedback of accommodation to reduce functional myopia.

Functional myopia may be defined as the refractive condition of the eye due to spasm of the ciliary muscle. As a result of the ciliary muscle spasm, the crystalline lens becomes more convex, creating a myopic refractive condition. The normal increase and decrease in the refractive power of the crystalline lens is know as accommodation and is controlled by the autonomic nervous system innervation to the ciliary muscle. Previous studies have reported that voluntary control of accommodation is possible by biofeedback training (Cornsweet & Crane, 1973; Randle, 1970). The present research investigated the application of biofeedback control of accommodation to reduce functional myopia. A double-reversal, multiple-baseline design was used to conduct the experiment. The results revealed that the three adult male subjects achieved the preset criterion, a 1/2-diopter reduction from initial baseline to a subsequent baseline. Further analysis of the data revealed even greater changes between initial baseline and feedback periods. Although generalization to a nonexperimental environment was not trained, each subject showed a reduction in myopia and an increase in visual acuity. The results of the experiment clearly demonstrated that functional myopia is subject to voluntary control.

Accommodation, Ocular↗
PubMed1981

The eyes of young chickens grow toward emmetropia.

The distribution of refractive errors was followed in chicks from hatching to 8 weeks of age. A dramatic progressive decrease in the variability of refractions was observed over this period. In addition, there appeared to be a parallel decline in hyperopia, even when the artifactual hyperopia of retinoscopy was taken into account. These results are evidence for a postnatal development regulatory mechanisms, most likely dependent on vision, which directs growth of the eye toward emmetropia.

Animals↗
PubMed1978

Biofeedback of accommodation to reduce functional myopia: a case report.

A 30-yr-old man received biofeedback training of his accommodation to reduce his functional myopia. There were seven training sessions for a total time of 34 min. Each training session consisted of a baseline-level recording period followed by a feedback period, a second baseline-level recording period, and then a second feedback period. Reduction of the functional myopia was learned within a few minutes. Since the training was conducted in a dark environment, myopia reduction was not expected in an illuminated environment. Nonetheless, some generalization was demonstrated with a reduction in the subjective measures of myopia (about 1 D for the right eye, 0.50 D for the left eye) and improvement in unaided visual acuity (from about 20/50 to 20/30 for each eye).

Accommodation, Ocular↗
PubMed1976

Neurological syndromes involving the visual system.

Because optometrists are the primary deliverers of eye care, their role in pathology detection is of primary importance. The neurological syndromes of the visual system have been reviewed and put into a chart format as an aid to the optometric clinician.

Eye Diseases↗
PubMed1976

The stimuli to accommodation in the optometric examination.

The study of the stimuli to accommodation has been a topic of particular interest to vision scientists for the past 40 years. Currently, as revealed by a review of the literature, there are 11 different stimuli to accommodation. While it is difficult enough to hold 10 stimuli constant to measure the effect of a single stimulus, stimulus control becomes an even bigger problem when we consider stimulus interactions. With 11 different stimuli there are 2,047 possible stimulus combinations. In the present paper, the authors discuss at length the relationship between stimulus control problems and clinical optometric routine.

Accommodation, Ocular↗