ment of CIs. They find that their rate of success is highest when training is broken down into the following phases:

a) Phase I — elimination of symptoms and normalization of accommodative and vergence functions.

b) Phase II — building excesses in the accommodation and vergences, i.e. +2.00/—2.50 binocular flipper rock with suppression control, up to 50 p.d. of convergence and 20 p.d. of divergence at near.

C) anti-suppression and sustaining ability. Each phase should take approximately four visits when combined with home training.

Patients often notice worsening of symptoms during the first few weeks of training. Rarely, they may even vomit from the exercises.⁴⁷ As long as the patient is informed that this may happen, no problems or unnecessary anxiety arises. Following this period of increased discomfort, most patients report that their symptoms disappear, concentration increases and near vision tasks are easier.

Since concentration and attention often improve as a result of therapy, CIs without subjective discomfort should also be treated. This is particularly true of children who have no reference point against which to gauge symptoms and, because of underdeveloped language skills, they have difficulty describing symptoms to parents and doctors. Since CI is more common in the learning disabled child, the authors feel that remediation, in the absence of asthenopia, is appropriate. The authors have seen many cases where symptoms, other than learning difficulties, have responded to treatment. However, dramatic changes occurred only in children who were experiencing lags in academic performance due to short attention span, poor concentration, inability to read for long periods of time, or poor retention. These are not the children manifesting severe learning disabilities.

Though most authorities agree that orthoptics or visual training

is the treatment of choice there are some patients who do not respond to this form of therapy. One author” who analyzed orthoptic failure in CI, noted that 37% of these patients manifested a systemic component e.g. anemia or glandular dysfunction. It is also true that some patients resist vision training and may be given home training and/or prism therapy.

Prisms may relieve some of the symptoms, but are rarely as effective as training. Only one author” advocates the use of prisms in all cases of CI. In his study, he presented three case studies which provided no controlled comparison. It should be remembered that prismatic lenses make the patient dependent upon a spectacle prescription. As mentioned above, prisms may always be utilized as a last resort. When necessary, the authors prescribe the least amount of prisms which eliminates an existing fixation disparity.

Hawkeswood53 advocates the use of surgical intervention, only when orthoptic therapy has failed. She performed surgery on a patient who had had orthoptic treatment at three different times and who experienced recurring symptoms each time. Hawkeswood reported that following surgery the patient remained asymptomatic. It should be noted that the follow-up period was only two months. This is too short a time period to conclude the permanence of the success of the surgery.

The only other form of treatment of CI mentioned in the literature is miotic therapy. However, Von Noorden et al³³ ob served that in his experience miotics only increase the exophoria and the discomfort of CI patients, and are therefore contra indicated.

Summary

CI patients have reduced convergence which manifests itself through lowered NPC, PFR, NRA, convergence activities. These patients may or may not manifest symptoms. The presence of symptoms in CI is depen

dent upon the amount and type of near work, degree of suppres sion and sensitivity to pain. Vision training as a mode of therapy in CI has been shown to be extremely effective. Effective ness of therapy is judged by relief of symptoms, improvement of concentration and reading skills, and improved accommodative and vergence abilities. AOA

Submitted for publication in the JAOA in November, 1977.

State University of New York State College of Optometry

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