Reduction of asthenopia after accommodative facility training.

Five patients reporting asthenopia secondary to accommodative deficiencies underwent automated accommodative facility training. A matched-subjects, crossover design was used to control for placebo effects. All patients receiving automated accommodative training showed a marked increase in accommodative amplitude along with a concurrent reduction of asthenopia. Decreases of blur and increases of reading time were the most frequently reported changes by patients. This experiment shows the effectiveness of automated accommodative training in reducing asthenopia and improving accommodative facility.

Prognostic value of laser interferometric visual acuity in amblyopia therapy.

There has been no simple clinical test which accurately predicts post-therapy visual acuity in amblyopic eyes. Since grating test patterns generally yield optimal visual acuity in amblyopic eyes, the authors sought to determine if pre-therapy laser interferometric grating visual acuity would predict conventional post-therapy visual acuity in functional amblyopia. In 90% of the patients who completed therapy, the pre-therapy laser visual acuity was within two lines of the post-therapy Snellen visual acuity. Thus, pre-therapy laser visual acuity is a good prognostic indicator of conventional post-therapy visual acuity in amblyopic eyes.

Vision function recovery during orthoptic therapy in an adult esotropic amblyope.

Orthoptic therapy was instituted in a 29-year-old patient having moderate amblyopia, constant small-angle esotropia, and large and steady eccentric fixation. This combination of factors, especially the age, pointed toward a poor prognosis for attainment of markedly improved vision function. Rate of recovery of several monocular vision functions was monitored during one year of orthoptic therapy. Results showed substantial improvement in most areas, thus providing evidence of neural plasticity at multiple sites in the visual pathways in this adult amblyope.

Clinical assessment of accommodative facility in symptomatic and asymptomatic individuals.

Clinical assessment of accommodative facility, using +/- 2.00 diopter flippers monocularly, was performed in asymptomatic and symptomatic populations in either single test sessions or multiple daily test sessions. In single session results, there was a trend for the average accommodative flipper rate to decrease as symptom level increased. The cut-off symptomatic/asymptomatic accommodative flipper rate was about 11 cycles per minute. In multiple session results, the average accommodative flipper rate, independent of symptom level, took approximately one week to asymptote to a stable level, with performance remaining at this level two weeks after termination of daily test sessions. Variability in daily flipper rate increased as symptom level increased. These results demonstrate the clinical usefulness of the +/- 2.00 diopter monocular flipper test in the screening for accommodative dysfunction.

Results of surgical treatment of intermittent divergent strabismus.

Inasmuch as surgery is often suggested as the primary treatment for intermittent exotropia, we undertook an extensive literature search to ascertain the outcome of this treatment. Surprisingly, only 22 papers were located which gave presurgical and postsurgical results for intermittent exotropia using reasonably clear success criteria. Many other papers were located but were excluded because they either failed to state the criteria used, lumped exotropia and esotropia together in their reported successes, or used orthoptics along with surgery. The total number of cases reported in the 22 acceptable papers was analyzed in terms of four levels of success to permit comparison across studies. These four levels were: functional success, motor alignment, cosmetically acceptable, and unsuccessful (no change or worse). The data are tabulated and summarized.

Orthoptic effects on accommodation and related visual functions in an adult alternating esotrope.

Orthoptic therapy was instituted in an adult, alternating esotrope with asthenopia who exhibited inaccurate static accommodative responses with adequate, clinically determined, accommodative facility. During and following therapy the patient showed considerable improvement in accommodative accuracy and related visual functions, such as contrast sensitivity, in the absence of any change in strabismic deviation. This case provides the first laboratory documentation of orthoptic effects on accommodation in an adult strabismic.

Reduction of asthenopia in patients with convergence insufficiency after fusional vergence training.

Seven patients with convergence insufficiency and related asthenopia underwent automated fusional convergence training. A matched-subjects control group crossover design was used to reduce placebo effects. All patients showed significant increases in vergence ranges with concurrent marked reduction of symptoms after training. All patients showed a flattening of and an increase in the base-out portion of their fixation disparity curve. Our results demonstrated the effectiveness of fusional vergence training in reducing asthenopia in these patients. Subsequent accommodation and vergence training using traditional orthoptic procedures yielded further reduction of asthenopia, as well as an increase in the base-out fusional range.

Use of forced preferential looking for measurement of visual acuity in a population of neurologically impaired children.

The forced preferential looking (FPL) technique has been used clinically, to assess visual acuity in infants for the past decade. It is generally accepted that the effectiveness of the procedure extends to the upper limit of 10 months of age. The authors discuss clinical observations on the viability of FPL as an effective technique in the measurement of visual acuity in an older population of neurologically impaired children.

Vision function recovery during orthoptic therapy in an exotropic amblyope with high unilateral myopia.

Orthoptic therapy was instituted in a 6 1/2-year-old patient having deep amblyopia, constant exotropia, and high unilateral myopia. The combination of these factors pointed toward a poor prognosis for attainment of normal monocular and binocular vision function. Rates of recovery of several vision functions were monitored during orthoptic therapy. Results showed marked improvement in most areas, thus providing evidence of neural plasticity at multiple sites in the visual pathways.

Static aspects of accommodation in human amblyopia.

Static aspects of accommodation in human amblyopia were investigated. Abnormalities uncovered included decrease in accommodative controller gain, decrease in slope of the accommodative stimulus/response curve, decrease in accommodative amplitude, and increase in depth of focus. Orthoptic therapy improved accommodative function in the amblyopic eye. Similar defects, but of lesser magnitude, were frequently found in the nondominant eyes of subjects in related test groups. This included former amblyopes who had received successful orthoptic therapy in their youth, which suggested lack of complete and/or maintained recovery of accommodative function, and strabismics without amblyopia, which suggested that the effects of strabismic suppression contributed to the accommodative deficits found in some strabismic amblyopes. The accommodative abnormalities found in our amblyopes were attributed to the effects of early, prolonged, abnormal visual experience on the sensory visual system.