June 1987

Training Accommodation—Cooper eta!.

431

patients having convergence rnsutflciency. Re-

suits indicated that after vergence training, but

not after placebo exposure, there was a signifi-

cant increase in vergence ranges. This corre-

sponded with marked reductions in patient rat-

ings of severity of asthenopia as measured by a

written questionnaire.

The purpose of the present study was to de-

termine if systematic and programmed monoc-

ular accommodative training could be used to

increase accommodative amplitudes and reduce

asthenopia of patients having accommodative

deficiencies. To minimize the potential contri-

bution of the binocular vergence system to the

accommodative system only mononuclar train-

ing was done. To control for experimenter bias,

placebo effects, and other sources of experimen-

tal confounding as noted above, the experiment

used a matched-subjects crossover design. We

used a written rating questionnaire for severity

of asthenopic symptoms.

METHODS

Two male and three female patients (mean

age, 27 years; range, 25 to 30 years) volunteered

for and completed the study. Diagnosis of an

accommodative anomaly with asthenopia was

made independently by at least two clinicians.

Criteria for inclusion in the study consisted of

each of the following: accommodative amplitude

less than 5.00 D (minus lens to blur), reduced

accommodative facility defined as monocular

failure to clear a —2.00 D lens within 5 s, and

positive relative accommodation less than 1.50

D. Each patient had to have no evidence of

amblyopia, strabismus, or vergence defect

(phoria greater than 4 pd exo or 4 pd eso; no positive

or negative fusional vergence less than 20 pd with

recoveries less than 10 measured with Risley

prisms at 40 cm). Best corrected visual acuity

was better than 6/9 (20/30). All patients had to

have the symptoms usually associated with an

accommodative anomaly such as blurred vision,

asthenopia, and/or decreased reading perform-

ance. Assessment of asthenopia was by a written

rating scale given to each patient (Appendix A).

Initially, each patient was given a full binoc-

ular evaluation by examiners who had no know!-

edge of the patient’s ocular status or the group

to which the patient had been assigned. The

following measurements were taken: distance

and near phoria; distance and near base-in and

base-out ranges; accommodative amplitude via

the push-up method and minus lens to blur

method; monocular estimate method for lag of

accommodation; base-out and base-in vecto-

gram ranges; stereopsis on a Randot test; and

accommodative facility using a ±2.00 lens. Each

patient completed a 3-item questionnaire de-

signed to rate the severity of their asthenopia.

Each item was scored on a scale of 1 to 5. The

asthenopia score was the summed score from

the 3 questions (range 3 to 15); the higher the

total score, the less the asthenopia.

After the binocular evaluation, the five pa-

tients were divided into two groups. The groups

were matched as closely as possible on the basis

of severity of asthenopia and accommodative

anomaly. Three were assigned randomly to the

experimental group and two to the control

group. Each group came to the clinic twice a

week for a 30-mm session. The only apparatus

used for accommodative therapy were two mod-

ified Keystone telebinoculars (Fig. 1). The ster-

eoscope was modified to separate the right and

left eyes. Each eye tube was enclosed to elimi-

nate extraneous light. The telebinoculars had

the +5.00 sphere prisms removed. An internal

light source, with an on-off cycle of 2.5 s resulted

FIG. 1. Monocular accommodative

training apparatus. Patient looks

through enclosed tubes at 6/7.5 (20/

25) equivalent print. Alternating light

with appropriate lenses stimulate ac-

commodation.