Intermittent Congenital Esotropia

INTERMITTENT CONGENITAL ESOTROPIA EUGENE R. FOLK, MD SKOKIE, ILLINOIS

Much has been written on the subject of congenital esotropia. Burian and von Noorden 1 note that this diagnosis has been generally accepted for an esotropia with an onset before six months of age. Parks2 further characterizes congenital esotropia as constant and the angle of convergence as large. Romano ,3 too, defines congenital esotropia as the presence of a constant esodeviation at four months of age. However, there are many children with an esotropia beginning before six months of age. whose eyes can be straight part of the time. The purpose of this paper is to study this group of patients with intermittent congenital esotropia and evaluate the natural history of this disease.

binocular potential. Even these comments were short notes in rather long and well-done articles dealing with the subject of constant congenital esotropia. This report is based on a retrospective study of 132 consecutive patients first seen under 12 months of age with a history of an esotropia beginning before six months of age. Costenbaderl ·has noted that parents frequently err in their diagnosis of strabismus, confusing pseudostrabismus with a true esotropia. By limiting patients in this study to those first seen under 12 months of age tended to minimize this error. Patients with previous surgery or a lateral rectus palsy or with Duane's syndrome were excluded from this study. Children with constant and intermittent deviations were included in order to make certain comparisons. Many of the patients had been followed for many years, but had first been seen under 12 months of age. They were included in the consecutive series because they were seen again during the time span of the study (about three years).

Little has been written about this group of patients. Costenbaderl noted that 14% of the 500 cases of infantile esotropia that he studied were esophoric or had an intermittent esotropia. These patients were found to achieve a higher incidence of fusional results. Taylor5 noted that 11% of the 200 patients that formed the basis of his study of surgical results in congenital esotropia were intermittent. These paOf the 132 patients in the study, tients were eliminated from a com- 62 patients had intermittent esoparative study of fusional results tropia and 70 patients had constant with early and late surgery because esotropia. A child was considered they were assumed to have a better to have an intermittent deviation if the examiner observed the eyes straight in the primary position or Submitted for publication May 24, 1979. the parents reported that the eyes From the Department of Ophthalmology, Abraham could be straight in the primary Lincoln School of Medicine, University of illinois, position. Children were not conMotility Section, illinois Eye and Ear Infirmary. sidered to have an intermittent deReprint requests to Old Orchard Professional Building, Skokie, IL 60076 (Dr Folk). viation if the eyes were straight in 2107

2108

EUGENE R. FOLK TABLE

1

DIAGNOSIS OF INTERMITTENT ESOTROPIA

49 patients were intermittent by history and examination 5 patients were intermittent byexamina· tion and constant by history 8 patients were intermittent by history and constant by examination

62

up or down gaze but were not straight in the primary position. The latter would be classified as constant esotropes. Parks2 has found that children with brain damage have variable deviations that improve with time. No children with severe brain damage were included. Seven children with developmental retardation (four constant) and two with spasmus nutans (one constant) were included. Frequently, we tend to suspect the accuracy of the parents' observations. However, Table 1 demonstrates that 80% of the time the parents and observer agreed when the deviation was intermittent. In the group of patients in whom esotropia was reported to be intermittent but seen as constant, the parents usually described the eyes as occasionally straight or rarely straight. It was true that five patients were seen to have intermittent esotropia but the parents stated TABLE

OPHTH AAO

that the eyes were never straight. Conversely, one child was reported to have intermittent esotropia but no deviation could be demonstrated until the third visit at seven months of age, three months after the mother had noted a deviation. Another child in this family had a constant congenital esotropia and this was the only reason to suspect the mother might be right and the child did have a deviation. This incidence of intermittent deviations (47%) in congenital esotropia is higher than those reported by Costenbader4 (14%) or Taylors (11 %). Consider too that Costenbader included phoric patients in his group. Even if one regards those patients reported to have intermittent but only seen with constant deviations as the latter, the percent of intermittent deviations would still be 41%. This probably reflects a bias in favor of intermittent deviations with closer questioning of the parents. The parents were asked "are the eyes ever straight?" If they responded affirmatively a great deal of time was spent observing the children to see if the parental observations were correct. Table 2 reflects an attempt to evaluate the magnitude of the deviation utilizing the Hirschberg test at the near position. The patients with constant esotropia seemed to be divided into two groups; those 2

MAGNITUDE OF DEVIATION IN CONGENTIAL ESOTROPIA CONSTANT ESOTROPIA

INTERMITTENT ESOTROPIA

60 measured 16 - 24 degrees 10 measured 32 - 48 degrees

59 varied between 0 - 24 degrees 3 varied between 0 - 32 degrees

All measurements by Hirschberg technique at near position.

VOLUME 86 DECEMBER 1979

INTERML'ITENT CONGENITAL ESOTROPIA TABLE INCIDENCE AND TYPE OF

3 A

CONSTANT ESOTROPIA

No. of patients

AND

V

2109

PATTERNS INTERMITTENT ESOTROPIA A

v

PATTERN

NO PATTERN

PATTERN

PATTERN

NO PATTERN

3

61

13

18

31

A

v

PATTERN

6

with small deviations measuring between 16 and 24 degrees of esotropia, and those with large deviations measuring between 32 and 48 degrees of esotropia. The intermittent deviations tended to be smaller, all but 3 of the 62 patients va ring between 0 and 24 degrees of esotropia. One of the more surprising findings in the study was the difference in the relative frequency of A and V patterns in the intermittent and constant groups (Table 3). Fifty per cent of the intermittent esotropes showed an A or V pattern while only 9% of the constant group had such a finding. This was even more striking when a careful evaluation of the 31 cases of intermittent esotropia with no pattern was made. All eight patients reported to have intermittent esotropia, which was seen as constant, demonstrated no pattern, similar to the low incidence of an A or V in the constant group (Table 4). Six of the patients with no A or V pattern had intermittent esotropia in straight up and straight down gaze and their pattern was difficult to classify. For example, a patient with 0 to 16 degrees of esotropia looking up and o to 16 degrees of esotropia looking down was considered to have no pattern. Five patients in this group were straight looking up and down

and were also considered to have no A or V pattern. If these patients are eliminated from consideration, 31 of 43 patients with an intermittent esotropia (80%) demonstrated an A or V pattern as contrasted with an incidence of 9% in constant deviations. The second portion of this study was concerned with determining the natural history of the disease. For the purposes of this discussion, only patients with a minimum follow-up of one year were included. Sixteen children were excluded because they did not fulfill this criterion. Table 5 summarizes what happened to the group of 46 children who were followed for at least one year. Five (11%) developed a constant deviation and their eyes were never straight again. Fifteen (33%) of the children remained unchanged. That is, their deviations continued TABLE

4

CHARACTERISTICS OF INTERMITTENT EsOTROPES WITH No A OR V PATTERN

8 patients were reported intennittent by history but were constant by examination 6 patients were intennittent in up and down gaze 5 patients were straight in up and down gaze 12 patients showed a significant and equal esotropia in up and down gaze

EUGENE R. FOLK

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TABLE

OPHTH AAO

5

COURSE OF DEVIATION IN INTERMITTENT CONGENITAL ESOTROPIA

No. of patients

UNCHANGED

STRAIGHT

WORSE

15

26

5

Minimum follow-up of one year's duration.

to be intermittent, not increasing in magnitude or frequency. One youngster in this group has been followed for 18 years. She and her parents state that her eyes rarely deviate and then only momentarily. However, she measures 30 prism diopters of esodeviation for distance and near and in addition has latent nystagmus and a small balanced alternating hyperdeviation. The remainder, 26 children (66%), improved and their eyes straightened, most with conventional strabismus therapy.

fixation or what Uristll called afixation, nor did any show unsteady central fixation. The fixation patterns were usually described as central and steady fixation monocularly but when the cover was removed, they would not hold fixation. This would suggest a level of amblyopia of 20/100 or better, in the amblyopic eye. In these ten children in whom the amblyopia was successfully treated, the eyes straightened out and remained straight. Some did require partial patching to maintain straight eyes. It should be noted that frequently the eyes did not become straight all of the time until the amblyopia had been eliminated.

Table 6 presents a breakdown of the therapy employed with these 26 patients. The eyes of two children straightened out without any therFourteen children had their deapy. One of these later developed bilateral elevation in adduction viation corrected with glasses. In with overacting inferior obliques eight children (Table 7) surprisbut the esotropia in the primary ingly small hyperopic corrections position did not recur. He subse- had a profound effect (+2.00 - +2.75). quently had a bilateral inferior When the glasses were going to oblique weakening procedure and correct the deviation, they were successful in doing so within two his eyes remained straight. months' time. Ten children demonstrated apSeventeen patients, five who got parent amblyopia on the basis of worse and twelve who were untheir fixation patterns. None of these demonstrated gross eccentric TABLE TABLE

6

TREATMENT OF PATIENTS THAT STRAIGHTENED OUT

2 straight without any treatment 10 straight when their amblyopia successfully treated 14 straight with glasses

7

REFRACTIVE ERROR OF THOSE CORRECTED WITH GLASSES NO. OF PATIENTS

REFRACTIVE ERROR

8 2 3

+2.00 - +2.75 +3.00 - +3.75 +4.00 - +4.75

1

-19.00

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INTERMITI'ENT CONGENITAL ESOTROPIA

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changed, underwent corrective sur- The parents should be closely quesgery. Three patients who were re- tioned and the child observed caregarded as unchanged had straight fully. eyes enough of the time that their parents felt they had little to gain This is an important differential from surgery. None of the patients diagnosis. In this group of patients, who had surgery were overcor- treatment of amblyopia is particurected, despite the fact that the larly important and surgery is best same amount and type of surgery deferred until it is certain that the was performed as if they had a con- vision is equal. Small hyperopic stant deviation. The exception to corrections (under +3.00) may have this rule was with regard to three a profound effect on the deviation. patients with intermittent devia- However, if corrective lenses will tions, who had straight eyes in straighten the eyes, a two-month down gaze and had a bilateral trial would seem to be adequate. lateral rectus resection. This is a If the eyes are not straight when procedure we only employ in pa- the vision is equal, glasses do not tients with intermittent A pattern help, and the deviation is unchanged esotropia where the eyes are straight or worse, standard motility surgery in the down position, or the patient is indicated, as if the deviation had previous bilateral medial rec- were constant. tus recessions. Some patients who were operated on, as well as som~ REFERENCES who did not have surgery, have later developed an exotropia in 1. Burian HM, von Noorden GK: Binocueither the straight up or straight lar Vision and Ocular Motility. St Louis, CV Mosby Co, 1974, pp 282-289. down positions. The findings of this study would suggest that intermittent deviations are more common among children with esotropia beginning before six months of age than previously reported. A and V patterns are far more common among intermittent than constant congenital esotropes to the extent that the presence of such a pattern should make the examiner suspect an intermittent deviation even though the deviation appears constant.

2. Parks MM: Ocular Motility and Strabismus. Hagerstown, Md, Harper & Row, 1975, 105-108. 3. Romano PE: Congenital esotropia: Definition, course, and management. J Pediatr Ophthalmol 8:88, 1971. 4. Costenbader FD: Infantile esotropia. Trans Am Ophthalmol Soc 59:397, 1961. 5. Taylor DM: Congenital Esotropia: Management and Prognosis. North Miami, Florida, Symposium Specialists, 1973. 6. Urist MJ: Eccentric fixation in amblyopia ex anopsia. Arch Ophthalmol 54:345, 1955.