AMBLYOPIA IN CASES OF READING FAILURE*

THOMAS HARRISON EAMES, M.D. Boston

The frequent appearance of amblyopia among children referred for failure in learning to read prompted an investiga­tion to find whether or not its incidence is really greater in such groups. The records of 100 children who failed to read were compared with those of an equal number

The group that had no reading trouble was found to be evenly divided between boys and girls.

The criterion of amblyopia was visual acuity of less than 20/20 in either or both eyes without demonstrable lesion, but un­improved by lenses. Each macula was ex-

TABLE 1 COMPARISON OF DATA FROM CASES OF READING FAILURE WITH THOSE FROM SUCCESSFUL READERS

Number of cases Age range in years Average age in years

Cases of reading failure

100 6 to 19

10

Successful readers

100 6 to 19

12

FREQUENCY (% of each group)

Amblyopia in either or both eyes Amblyopia in both eyes Amblyopia in left eye only Amblyopia in right eye only

Both eyes equally amblyopic Both eyes amblyopic, left the more so Both eyes amblyopic, right the more so Better vision with both eyes than with either

separately

25 21

4 0

17 3 0

12 11

1 0

6 2 3

CENTRAL TENDENCY

Average (arithmetic mean) visual acuity of am­blyopic cases (Snellen)

Right eyes

20/40

Left eyes

20/60

Both eyes

20/30

Right eyes

20/40

Left eyes

20/50

Both eyes

20/30

known.to be passing in reading but who had been referred for ocular complaints. The age range of the two groups was from 6 to 19 years, the average age of the poor readers being 10 years and that of the others 12 years. As is common in groups of reading-failure cases, previous­ly studied by others as well as myself, 80 percent of the poor readers were boys.

* From the School of Education, Boston University.

amined with particular care, but no lesions were seen here nor elsewhere in the f undi of any eyes in either group. The poor readers exhibited twice as great a fre­quency of ambyopia of all categories, slightly less than twice as frequent bilat­eral amblyopia, and four times as fre­quent amblyopia of the left eye only. No cases of amblyopia in the right eye only were found in either group. A little less than three times as many poor readers were equally amblyopic in each eye. The

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AMBLYOPIA IN CASES OF READING FAILURE 1375

incidence of bilateral amblyopia with a greater degree of defect in the left eye was only slightly different in the two groups, whereas the poor readers pre­sented no case in which the amblyopia was greater in the right eye than in the left. Twice as many poor readers experienced better vision binocularly than with either eye separately. A quarter of the same group were amblyopic in one or another category and about a fifth of them were amblyopic in both eyes.

The average amount of amblyopia was studied in terms of visual acuity below 20/20. The only difference between the groups in this respect was that the poor readers showed an average of one Snellen line poorer vision ( that is, greater ambly­opia) in the left eye. The average visual acuity for the right eyes only and both eyes together was the same in each group.

Amblyopia may be either a neurologic defect, concomitant with partial word blindness, or a primary factor impairing reading ability through visual inefficiency. It is probably one of many physical fac­tors that participate to a greater or less degree in different cases of reading fail­ure. The fact that the incidence and aver­age amount of amblyopia of the left eye

only was greater among poor readers dis­closes an unexpected tendency which will bear investigation in later studies.

The treatment of children who fail to read and are amblyopic involves the usual remedial teaching techniques supple­mented by sightsaving-class methods, when vision is very poor, and by ambly­opic exercises. Not much is to be expected of such exercises, but they should be tried. Sometimes surprising visual gains follow, especially among children in the lower grades. This may be due to late matura­tion. If so, amblyopic exercises may fos­ter the process of visual development.

S U M M A R Y

The records of 100 cases of reading failure were compared with those of an equal number of children who were known to be passing in their school studies. A considerably greater incidence of amblyopia was found among the poor readers, and they exhibited a greater average amount of amblyopia in the left eye only. The average amount of ambly­opia in the right eye only and in both eyes was the same in each group.

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