June 1988

Orthoptics for Convergence Insufficiency—Cooper 459

training instruments have become available. The first was the CAT distributed by Bernell Corp. Recently, Computer Orthoptics, distributed by Teletherapy (Indianapolis, IN), has developed a computerized system for diagnosis and treatment of binocular anomalies. These systems present anaglyphic binocular stimuli, which may be changed or altered instantaneously to produce any vergence demand up to 50 ^. Diagnostic programs include standardized fusional range testing with four different targets, RDS presented in an operant conditioning paradigm to measure fusional ranges automatically, different first degree targets to measure phorias, subjective angle and objective angle, motor fields to determine muscle paresis, and accommodative facility testing. Testing procedures are standardized in computerized systems, removing examiner and interexaminer variability.

Behavior modification techniques are used with Computer Orthoptics to foster patient cooperation, which in turn may improve patient response. Correct responses are reinforced positively by auditory feedback and by increasing vergence demand. Incorrect responses are denoted by a “boop” sound and associated with a

reduction in vergence demand. Thus, the patient’s own responses modify the training regimen; i.e., patients “go at their own speed.” Other training programs are designed to improve vergence ability with flat fusion targets. In addition, vergence programs automatically separate targets within established ranges at controlled speeds. The speed of vergence can be changed easily. Various jump duction techniques have been designed which produce unpredictable vergence demands. Furthermore, RDS have been incorporated within a jump vergence program to improve step or voluntary vergence ranges automatically. The following cases are illustrative and generally representative of how automated vergence therapy is performed.

PATIENT 1

A 6-year-old noncommunicative female received a routine eye examination. Her mother stated the girl complained of frequent, dull aching headaches occurring in the afternoon, and double vision; other ocular and health histories were normaL

Best corrected vision with piano OU was 6/6 (20/20) either eye. Extraocular movements were full and concomitant. Slitlainp examination and

SESSIONS

Fia. 4. Prism diopters of fusional vergence and total asthenopia scores (ordinate) of patient are plotted against the number of sessions (abscissa). The weekly sessions are divided into baseline (B). control (C), experimental (E). and orthoptics (VT) phases. Patient in the left panel had control RDS training followed by the experimental phase, whereas the patient in the right hand panel had the experimental phase followed by the control portion. Baseline findings were measured on patients before testing and after control, experimental, arid orthoptics (vision training) phases. Asthenopia scores (U). RDS fusional convergence break points in prism diopters (0), and vectrographic fusional convergence break point in prism diopters (•) were measured during baseline testing. ADS fusional convergence break points and vectographic fusional convergence break points were measured during each session of the experimental phase. Fusion range measurements were not taken during the control phase. (Reprinted from Am J Optom Physiol Opt 60:985.1985.)

Principal author has proprietary interest