General binocular dysfunctions in an urban optometry clinic Steven C. Hokoda, 0.0.

Abstract: The prevalence oj general binocular dysfunction with asthenopia was deter­mined for non-presbyopes aJ. an urban optometry clinic serv­ing municipal workers and their dependents. Of the sam:" pIe of119 patients. 42.9% had jobs wilh heavy desk work de­mands (primarily secretarial and clerical) and 39.5% were studertls. De prevalence ot s 'm tomatic en 7 bmocu­

'S untion was 21.0 o. Ac­commodative ysJunctions were the most commonly' en­countered condition aC 16.8%.

. SJ'mplomatic near esophoria was found in 5.9% ofpaJients and convergence insufficiency in 4.2%. Both vergence dys­funci ions overlapped. with ac­commodative dysfuncliQns.

Key words: prevalence, gen­eral binocular ·dysfunction. esophoria, convergence insuf jiciency. accommodative dys­funelion. asthenopia

(ntroduction

Although general binocular dys­functions (non-strabismic or am­blyopic) are a popuJar topic in the ophthalmic literature,' very little prevalence data is available.2 For the one condition that has been fre­quently reported on, convergence insu fficiency, a wide range of prev­alence rates are seen, although most are between one and ten percent.2,)

Accommodative dysfunctions are also commonly discussed; but prevalence data is sparse,l Robinson" found a 14.4% preva'­

lence of accommodative insuffi­ciency in a small group (n = 13) of normal children, while Hoffmans

found clinically abnonnal accom­modation in 44% of twenty-five non-learning disabled children. Nei­ther study reported on associated asthenopia. Hennessey et al6 had a 23.3% prevalence rate for sympto­matic accommodative infacility among sixty randomly selected chil­dren who had previously passed a comprehensive visual screening. Morgan's' normative data predicts about twelve percent of non-pres­byopes will have significant near esophoria (>2 prism diopters), but prevalence of symptomatic near esophoria has not been reported.

Presented here are prevalence figures for symptomatic general bi­nocular dysfunctions (near es0­

phoria, convergence insufficiency, accommodative insufficiency, ac­commodative infacility, and accom­modative spasm) among non-pres­byopic clinic patients at an urban optometry clinic for municipal workers and their dependents.

Method

Clinic records were reviewed for pa­tients seen by the author between September, 1981, and March, 1982, at a municipal workers' union op­tometry clinic serving union mem­bers and their dependents in New York City, New York. The author saw patients on a part-time basis and examined approximately 390 patients. An estimated 4000 pa­tients were seen at the clinic during this period. Only records for pa­tients aged thirty-five years and younger were reviewed in order to minimize overlap of accommoda­tive dysfunctions with presbyopic changes.

General binocular dysfunction patients had both abnonnal clinical

findings and associated asthenopic symptoms which would not be ad­dressed by correction of the refrac­tive error alone. They had healthy eyes and no strabismus or ambly­opia. Patients with abnormal clini­cal findings but who were asymp­tomatic were excluded and counted as normals, as were those patients with asthenopia but whose accom­modative-convergence findings were normaL Dysfunctions were di­vided into vergence dysfunctions (near esophoria and convergence in­sufficiency) and accommodative dysfunctions (insufficiency, infaciJ­ity, and spasm). Table 1 lists criteria for inclusion within each dysfunc­tion group. Qinical norms were de­rived from Morgan's norms' and Pacific University College of Op­tometry norms,' and generally rep­resent at least one standard devia­tion from the mean finding for that measure..

Results

One hundred and nineteen non­presbyope records were reviewed. Errors in recordkeeping probably account for about a ten percent un­selected undercount of patients ex­amined. Mean age for the &roup was 22.9 ± 9.0 years, with the youngest be.ing four years ofage (one girl and one boy).

Table 2 presents the general binocular dysfunction data. Overall. 21.0% showed abnormal clinical findings and associated asthenopia. Mean age of dysfunction patients, 22.7 ± 8.3 years (youngest, a six year old girl), was not significantly differ­ent from the mean age ofall patients (t = 0.83, p> 0.20). Female to male ratio for general binocular dysfunc­tion patients, 68.0%/32.0%, did not differ significantly from the ratio for non-dysfunction patients, 67.0%/ 33.0% (x 2 = 0.02, p> 0.20).

560 Journal of the American Optometric Association

Near esophoria had a 5.9% prevalence rate, with 71.4% of these patients showing an accommoda­tive dysfunction (57.1 % with insuf­ficiency and 14.3% with infacility). Convergence insufficiency occurred in 4.2% of patients, with 40.0% also having an accommodative dysfunc­tion (20.0% with insufficiency and 20.0% with infacility). The most prevalent conditions were accom­modative dysfunctions, with a 16.8% occurrence rate. The most common accommodative dysfunc­tion was insufliciency. 9.2% (36.4% of these patients had near esophoria and 9.1 % had convergence insuffi­ciency), followed by infacility, 5.1 % (16.7% with esophoria), and spasm. 2.5% (33.3% with convergence in­sufficiency), Table J provides a

breakdown of the accommodative dysfunction data.

As for near visual demands, 48.0% (n = 12) of dysfunction pa­tients had primarily desk work re­lated jobs (largely secretarial and clerical): 40.0% (0 = 10) were stu­dents; and 12.0% (n = 3) had min­imal near visual demands. For non­dysfunction patients, 41.5% (n = 37) had jobs primarily near work oriented (again largely secretarial and clerical); 39.4% (n = 34) were students; and 19.1% (n = 18) had minimal near visual demands. A chi-square comparison of dysfunc­tion patients and non-dysfunction patients showed no significant dif­ference io these visual demand dis­tributions (x 2 = 0.77. p> 0.20).

Discussion

The population sample reviewed here showed overall strabismus and amblyopia prevalence rates similar to previously reported general pop­ulation figures (5.9% strabismus prevalence versus a general popula­tion prevalence of about six per­cent,l and 20/40 or worse best spec­tacle corrected amblyopia preva­lence of 2.5% versus a general pop­ulation figure of about three

IOpercentl. ). Further, the 4.2% con­vergence insufficiency occurrence rate was consistent with previously reported prevalence rates.2•3 These similarities allow one to look at the esophoria and accommodative dys­function occurrence rates, as well as the overall 21.0% general binocular

Table. 1: ~Jassification criteria for: general binoc~lar dysfuri<?tions,"

Vergence Dysfunctions Esophoria

. Patient must show both: 1. Near fj:SOphoOa >2 prism diopters. '. '. 2. Symptoms with vergence testing sUnitar to those wfth habCtuaI use of the eyes. 8.r'd/or ~~..CXX'!lfort with COflY8X laos adds

redodng the eso de~tion. . . . ' .. ' .

In additioo. patient must have either. 1. Decreased refative ~«geoc:e. ::s9/17/8. tor ~ur. diplopia. and fusion recovery (at least one finding 1oW). 2. Eso~ation disparity at near (rnooocuIaI1y seen fiduciary lines wfth 8 3.6 degree round first fu~ con~.

Convorgence Insuftidency PatHiKlt must show:

1. Symptoms associated with V6f"genc6 tosting similar to symptoms habituaftv Olq...A1enoed wtth near visual demands. In addition, patient must have ettner: .. .' .

1. Convergence nearpoklt equal to or ou~ 5"[7" for bss and re<::oYe(y Of fuston. aoo/Of' excesstve, s~ to maintain fusion It or outside 8"'. . •....

2. Decreased ~tive convergence. :s12/15/4. for bkK, diplopia, and fusion reco "'1 (at least one w,,<.. Aoc;ommodative Dysfunctions .

In6ufflc;iency Patient must show:

1. Symptoms with aocommodative testing sit"nKar toflatlftual ~ye ~; and/or i\cr8ased comfort wtth c:onvex lens adds. In addition, patient must ha\<e either: '.' . :

1. Decreased positive reCative accommodation, :51.250. . . . 2. Push-up accommodative ampfitude at least two diopters be40w Hofstette('s calculation for minimum ega apprOjlOate ampItude:

15 - .25 x age In years.' " .' . InfadIity

Patient must have ooth; . . , 1. 8rur end/Of" ast:h8nopic symptoms with habitual near tasks simRar to symptoms generated by accommodativ~ t~. eM/«

increased comfort with convex lens adds.' . ; 2. Normal positive refaUve accommodatioo and accommodatfve arnpfitude (pustHJp amplitude not routinely measured).

In addftion, patient must have eCther: 1. Deaeesec1 accommodative -rocks.- :515 cydes/minute with -2.000 add over the subjective refraction ~ 20/20 !:;:ttera el

40cm. . .' '. 2. Increased aocommodatfve lags: binocular cross cyiinder add, <1.250; M~M retinoscopy lag. C!!O.750; and/CK low neutral

retinOscopy add. ~1.500. Aft referenced to the subjective re~ (both retlnoscopytecflnlques had the patient 0f8Ity read 201 100 letters at 40 em.). .

I)pasm Patient must have:

1. History of variable acufty. asthenopia, end/Of symptoms from accommodative testing similar to habitual symptoms. 2. A difference of at least one diopter (ffiO(e p4us or leSs minus measured) between stali<; retinoscopy and the subjoctive refraction

with varia~ subjective responses. . Variable visual acuity at distance without change of lenses.

Volume 56, Number 7, 7/85 561

Table 2: Prevalence of general binOCular dysfunctions .

Frequency of 'OCCUITeoce

Esophoria 1,7% (2 females) Esophoria with accommooative dys­ 4.~/o (3 females,. 2 maJe~)

function Convergence insufficiency Convergence in$uffldency with ac­

2.50/0 (2 femaJes~:l rnaJe) 1.7% (1 female, 1 maler'

commodative dysfunction . Accommodative dysfunction 10.9°10 (9 female.s. 4 m~s) Totcl 21.0~9 (17 females, 8 mates)

References

I. Griffin JR. Binocular Anomalies: Pro­cedures for Vision Therapy. 2nd ed. Chi­cago: Professional Press. J982.

2. Bennett RG. Blondin M. Ruskicwicl J. Incidence and prevalence of selected visual conditions. J Am Oplom Assoc 1982:53:647-56.

3. Cooper J. Duckman R. Convergence in­sufficiency: incidence, diagnosis. and treatment. J Am Oplom Assoc 1978: 49:673-80.

4. Robinson BN. A study of visual function in institutionalized juveniles who are demonstrated underachieving readers. Am J Optom Arch Am Acad Optom 1973:50: 113-6.

Table 3: Accommodative dysfunctions

Pen:eot withPercentot ~tfve

i

Cooy«-genceEsophoOadystunctions Jnsufftdency

Insufficiency 55.0 (9 females. 2 males)

Infacility 30.0 (4 females, 2 males)

Spasm 15.0 (3 males) Total 100.0 (13

females. 7 males)

dysfunction prevalence. with an eye toward wider application of these figures for the general population. Purcell et alII provide an indirect comparison figure for symptomatic binocular dysfunctions. They re­viewed patient charts (n = 125) at an optometry colJege clinic for twenty-five to thirty-five year oids without strabismus. amblyopia. eye pathology. or current contact lens wear. and found that 30.8% of pa­tients received treatment other than or in addition to the subjective re­fraction for symptoms associated with the use of the eyes.

The high occurrence of general binocular dysfunctions with associ­ated asthenopia justifies the atten­tion given to these problems in the

36.4 (2 females, 2 males)

16.7(1 temale)

9.1 (1 ,female)

0

0 25.0 (3

femaJe~, 2 males)

33.3 (1 male) '10.0 (1 ferT}8Je,

.,1'~$l'

ophthalmic Ijterature. As many of these dysfunctions can be ad9ressed to the benefit of the patient with proper lens, prism, and/or orthoptic therapY,I2-15 conscientious opto­metric care should include ade· quate case history probes and ac­com modative-con vergence testi ng to identify and treat these common problems. ••

Submitted for publication 10/84 Revised 2/85

Group Health Cooperative of Puget Sound

Central Speciality Center Wing G-Eye Clinic

200 15th Avenue East Seattle, Wa 98112

5. Hoffman LG. Incidence of vision diffi­culties in children with learning disabili­ties. J Am Optom Assoc 1980;51:447­51.

6. Hennessey D. losue RA. Rouse MW. Relation of symptoms to accommoda­tive infacility of school-aged children. Am J Oplom Physiol Opt 1984:61: 177­83.

7. Morgan MW. The clinical aspects of ac­commodation and convergence. Am J Optom Arch Am Acad Optom 1944; 21:301-13.

8. Haynes HM. Monograph on elementary visual training case analysis: clinical norms. Forest Grove. Oregon: Lc:arning Resource Center. Pacific University Col­lege of Optometry, 1970.

9. Barish 1M. Clinical Refraction. 3rd ed. Chicago: Professional Press. 1975: 170 .

10. Shapero M. Amblyopia. Philadelphia: Chilton Book Co, J97 J:56-66.

'I. Purcell lR. Nuffer JS, Gements SO, Gausen LR. Schuman DO, Yoltan RL The cost effectiveness of selected opto­metric procedures. J Am Optom Assoc 1983;54:643-7.

12. Haynes HM. Brattis NJ, Egger MJ. Ef­fects of bifocals and reading &Jasscss on near point visual complaints and fixation disparity in myopes with hypoposturing accommodative perfonnance. Tran­scripts of the OEP Skeffington Sympo­sium on Visual Training. 1980; Leban­non. Oregon: Caryl Croisanl.

13. Daum KM. Accommodative dysfunc­tion. Doc Ophth 1983;55: 177-98.

'4. Daum KM. Convergence insufficiency. Am J Optom Physiol Opt 1984;61: .6­22.

15. Shttdy JE. Actual mea.,,>uremenl of fixa­tion disparity and its usc in diagnosis and treatment. J Am Optom Assoc 1980; 51: 1079-84.

562 Journal of the American O~t'lmetric Association