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Vol. 60, No. 12, pp. 982-989

AMERICAN JOURNAL OF OPTOMETRY & PHYSIOLOGICAL OPTICS

Printed in U.S.A.

Reduction of Asthenopia in Patients with

Convergence Insufficiency after Fusional

Vergence Training

JEFFREY COOPER,* ARKADY SELENOW,t KENNETH J. CIUFFREDA,f

JERRY FELDMAN,~ JAMES FAVERTY,t STEVEN C. HOKODA,t and

JAYNE SILVERt

State College of Optometry, State University of New York, New York, New York

ABSTRACT

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 f u-

sional vergence training in reducing astheno-

pia in these patients. Subsequent accommo-

dation and vergence training using traditional

orthoptic procedures yielded further reduction

of asthenopia, as well as an increase in the

base-out fusional range.

Key Words: convergence insufficiency, as-

thenopia, orthoptics, fixation disparity

Convergence insufficiency, a common binoc-

ular vision disorder is often associated with as-

thenopia. The disorder has been reported to

occur in 1.75 to 25% of the population.1-3 Vari-

ability of the reported incidence of convergence

insufficiency reflects differences in definition,

methods of measurement, and patient popula-

tions.

Traditional treatment of convergence insuf-

ficiency typically involves orthoptic techniques,

Received March 9, 1983; revision received Septem-

ber 1, 1983.

* Optometrist, M.S., Member of Faculty, F.A.A.O.

t Optometrist, Member of Faculty.

Optometrist, Ph.D., Member of Faculty, F.A.A.O.

§ Ph.D., Member of Faculty.

which have a reported success rate of over 90%

in alleviating asthenopia.4 Although many stud-

ies have used large samples (e.g., N > 200), most

have failed to use experimental procedures that

allow for proper evaluation of the therapeutic

intervention.5-8 Thus, experimenter bias, pla-

cebo effects, and concurrent multiple therapeu-

tic techniques are not ordinarily assessed as

factors related to subsequent changes in ver-

gence ability and/or asthenopia. One study of

the effects of vergence training on vergence per-

formance demonstrated that progressive in-

creases in vergence demand, rather than simple

exposure to stereoscopic targets with minimal

vergence demand, produced increases in ver-

gence ability in patients with a variety of bin-

ocular vision disorders.9

Our study evaluated the effects of fusional

vergence training on both fusional vergence abil-

ity and asthenopia in patients with convergence

insufficiency. In addition, the effects of fusional

vergence training on fixation disparity and Ogle-

type forced vergence responses were investi-

gated.’0

METHODS

Three male and four female patients (mean

age, 25 years; range, 16 to 29) volunteered and

completed the study. One patient dropped out

before completion. Diagnosis of convergence in-

sufficiency with accompanying asthenopia was

made independently by two clinicians.

To be classified as having convergence insuf-

ficiency, a patient had to meet two of three of

the following criteria:4 nearpoint of convergence

greater than 7.5 cm with a recovery greater than

12.5 cm using an accommodative target;” a near

base-out fusional range less than twice the de-

mand (Donder’s criterion); and base-out ranges

at near equal to or less than 2 SD’s below the

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