- Email: [email protected]
Treatment outcomes in refractive accommodative esotropia
Treatment Outcomes in Refractive Accommodative Esotropia A. Tu¨lin Berk, MD,a Nilu¨fer Koc¸ak, MD,b and Hu¨lya Ellidokuz, MDc Purpose: To document and compare the clinical features and functional outcomes in patients with accommodative esotropia. To assess the efficacy of conventional management of accommodative esotropia, to determine functional outcomes of amblyopia and binocular vision, and to analyze possible risk factors involving the development of amblyopia. Methods: We retrospectively reviewed the charts of 147 patients whose esotropia was corrected to within 10 prism diopters of orthotropia at both distance and near with use of full cycloplegic hyperopic correction. Multiple parameters were reviewed, including initial and final cycloplegic refraction, distance, and near deviation with and without glasses, stereoacuity, age of onset, and initiation of treatment, presence of anisometropia, and change in hyperopia. Results: At presentation, 87 (59.2%) of the 147 patients were amblyopic, and anisometropia was found to be the only statistically significant risk factor for this(P ⫽ .001). Only 24.2% of these patients have stereo acuity between 40 and 100 sec/arc, 20.96% of patients have 200 to 800 sec/arc, and 22.58% of patients have 1980 to 3000 sec/arc; the remaining 32.26% had no stereo acuity. Fusion was achieved in 73.5% of the patients and later presentation (⬎ 24 months) of esodeviation significantly determined their fusional ability (P ⫽ .031). Consecutive exotropia developed in 5.4 % of the patients an average of 5.5 years after institution of full optical correction. For clinical and functional outcomes we did not find any statistically significant difference between early onset (before 1 year old) and typical onset (2 to 3 years) age groups. The trend towards decreasing hyperopia was apparent, averaging ⫺0.16 ⫾ 0.20 diopters annually in 80.5% of the patients with at least 5 years follow-up, although 23% of patients still had 20/40 or worse visual acuity in the amblyopic eye. Conclusions: Amblyopia is a commonly associated finding at presentation for patients with accommodative esotropia. Most of the patients developed good fusion but poor stereopsis at the end of treatment. (J AAPOS 2004;8:384-388) ccommodative esotropia usually presents in a child between two and three years of age, with a range of six months to seven years. The angle of esodeviation is equal for distance and near in accommodative refractive esotropia, in which the accommodative convergence/accommodation ratio is normal. Glasses to correct hyperopia are the mainstay of treatment and if any amblyopia is present this should be treated.1-4 Most children with accommodative esotropia should have a favorable prognosis for binocularity since the deviation usually develops after age two.5 This study assessed the efficacy of conventional management of refractive accommodative esotropia, determined the functional outcomes in terms of amblyopia and binocular vision, and analyzed possible risk factors involving the development of amblyopia.
A
From the Department of Ophthalmology,a,b and Department of Public Health,c Dokuz Eylul University, Y´zmir, Turkey. This study was partially presented at the Twelfth Congress of the European Society of Ophthalmology, June 2001, Istanbul, Turkey. Submitted December 2, 2002. Revisions accepted February 2, 2004. Reprint requests: A. Tu¨lin Berk, Huseyin Zeren Cad., Urla Berk Sitesi No: 143, Urla, Y´zmir, Turkey; e-mail: [email protected] Copyright © 2004 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2004/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2004.02.001
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METHODS AND MATERIALS We retrospectively reviewed the charts of 147 patients with accommodative refractive esotropia seen in our clinic between May 1992 and January 2001. There were 63 girls and 84 boys. For a diagnosis of refractive accommodative esotropia, patients had to have esotropia that was corrected to within 10 prism diopters (PD) of orthotropia at both distance and near with use of full cycloplegic hyperopic correction. Exclusion criteria included accommodative esotropia patients with high accommodative convergence/accommodation ratio, follow-up of 6 months or less, deteriorating accommodative esodeviation, history of developmental delay, and any form of neurologic impairment. All patients underwent a full ophthalmologic examination including orthoptic assessment, cycloplegic refraction, and binocular single vision, where cooperation was adequate. Binocular sensory testing was performed through the patient’s optimum hyperopic correction. Cycloplegia was accomplished with one drop of 1% cyclopentolate and 1% tropicamide, repeated in five to ten minutes, with retinoscopy performed after 60 minutes. Cycloplegia was repeated at least twice a year for all the study patients. The initial step in treatment was full correction of the hyperopia. As these patients had normal ratios of accomJournal of AAPOS
Journal of AAPOS Volume 8 Number 4 August 2004
modative convergence to accommodation, bifocals were not required. Occlusion was prescribed to treat amblyopia as soon as the effects of corrective lenses were established. An interocular difference of two or more Snellen lines was considered as amblyopic. Best-corrected visual acuity was measured using the Snellen chart where possible. The CSM (central, steady, maintained) was taken into account according to the bilateral fixation pattern in patients whose visual acuity could not be measured. Lack of alternate fixation and a strong unilateral objection to occlusion were considered diagnostic of amblyopia in the younger age group. Greater than 1.0 diopter difference between each eye was considered significant anisometropia. The onset of deviation was determined by family description and old photographs. The deviation with and without glasses was measured by the prism cover test in all cases. Ocular movements and convergence were evaluated. Stereoacuity was tested with TNO (Lame´ris Ootech, Groenekan, The Netherlands), Titmus fly test (Stereo Optical Co., Chicago, IL), and fusion with the Worth 4-dot test where cooperation was adequate. For purposes of our analyses, patients were divided into two groups, amblyopic (n ⫽ 87) and nonamblyopic (n ⫽ 60). To find out possible risk factors in the amblyopic group multiple parameters were reviewed, including sex, initial and final cycloplegic refractive error, distance and near deviation, stereoacuity, and time interval between onset of deviation and initiation of treatment. Twenty-five of the children had onset of refractive accommodative esotropia before 1 year old. Records of the 122 children with more typical age at onset of refractive accommodative esotropia were reviewed as controls for this subgroup. Clinical characteristics and treatment outcomes were compared between the two groups. The data were stored on a computerized database and analyzed using SPSS for Windows 8.0 (Statistical Package for Scientific Studies for Windows, SPSS Inc., Chicago, IL). Statistical analysis included the Mann Whitney U test, the Friedman two-way analysis of variance (ANOVA), the Wilcoxon, and the Student’s t tests where appropriate for continuous data, and the 2 and Fisher’s exact tests where appropriate for categorical data.
RESULTS The charts of one hundred forty-seven patients with accommodative esotropia were reviewed in the study. Thirty-nine patients with follow-up under 6 months were excluded from the final examination. The mean follow-up period was 43 months (range, 6 to 120 months; median 36). Amblyopia Eighty-seven (59.2%) of 147 patients were amblyopic at the time of initial examination. Mean age at onset of esodeviation, mean age at initiation of treatment, mean refractive error, mean angle of deviation with and without
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TABLE 1. Comparison based on amblyopia at the initial examination (the time of presentation) P Amblyopic Nonamblyopic Value Total number of patients 87 (59.2%) Mean age of onset (mo) 42.04 Mean age of initiation of treatment 53.07 (mo) Mean refractive error (diopters)* OD ⫹5.11 OS ⫹5.03 Mean deviation (pd without glasses) Distance 23.32 Near 24.79 Mean deviation (pd with glasses) Distance 2.78 Near 4.36 Anisometropia† (number of patients) 30 (34.5%)
60 (40.8%) 40.05 46.53
0.631 0.128
⫹4.50 ⫹4.44
0.053 0.063
22.27 23.17
0.639 0.415
3.35 4.95 7 (11.6%)
0.500 0.478 0.001
*Mean spherical equivalents; †Anisometropia: One diopter difference between right and left eye; PD: Prism diopters; MO: Month; OD: right eye; OS: left eye.
correction, and presence of anisometropia were compared between amblyopic and nonamblyopic groups to find out the possible risk factors (using the t test and 2). Results are summarized in Table 1. The interval between onset of strabismus and initiation of treatment was shorter in the nonamblyopic group, but this did not result in statistical significance (P ⫽ .05). Also, the mean cycloplegic refractive error was lower in the nonamblyopic group, but it was not statistically significant. Anisometropia was found to be the only statistically significant risk factor for the development of amblyopia in patients with accommodative refractive esotropia (P ⫽ .001). Treatment with occlusion was conducted in all amblyopic patients and none of the patients were noncompliant for both patching and wearing glasses. At the most recent examination, 15 (23%) of 65 amblyopic patients (22 were lost to follow-up) still had 20/40 or worse visual acuity in their amblyopic eye. Sixty-three percent of the patients reached equal visual acuity in both eyes by the end of occlusion treatment. Binocular Status Stereoacuity measurements were available at the end of the spectacle wear for 124 study patients, and ranged from zero to 40 sec/arc, with 84 of 124 patients (67.7 %) having measurable stereoacuity. Stereoacuity measurements were not available for the other patients because of young age, poor cooperation, or lack of documentation. While 24.2% (n ⫽ 30) of these patients have stereoacuity between 40 and 100 sec/arc, 20.96% (n ⫽ 26) of patients have 200 to 800 sec/arc and 22.58% (n ⫽ 28) of patients have 1980 to 3000 sec/arc; the remaining 32.26% (n ⫽ 40) had no stereoacuity. The ANOVA test revealed that two factors, age at onset of esodeviation (P ⫽ .271) and initiation of treatment (P ⫽ .645), had no effect on the outcome of stereoacuity.
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TABLE 2. Changes in hyperopia Number of Patients Number of eyes Initial refraction (diopters) Observation interval (month) Annual change in hyperopia
23*
59†
46 4.79 ⫾ 1.54 D (1.00–7.62 D) 79.1 ⫾ 17.8 mo ⫺0.16 ⫾ 0.20 D
118 4.44 ⫾ 1.75 D (1.00–8.0 D) 61.2 ⫾ 23.8 mo ⫺0.15 ⫾ 0.33 D
*: Patients who had at least 5 years follow-up; †: Patients who had at least 3 years follow-up; mo: month
TABLE 3. Direction of change in hypermetropia Number of Patients Number of eyes Increase Decrease Same
>5 Years Follow-Up (n ⴝ 23) 46 6 37 3
%
<3 Years Follow-Up (n ⴝ 59)
%
13.0 80.5 6.5
118 21 66 31
17.8 55.9 26.3
Fusion was evaluated in 135 patients. One hundred eight patients (108) had fusion, based on the Worth 4-dot test (73.5%). Age at onset of deviation was significantly higher in patients with fusion (P ⫽ .031) while age at initiation of treatment had no positive effect on development of fusion (P ⫽ .850). If the age of onset of deviation was greater than 24 months the likelihood of having fusion was higher in our study population (P ⫽ .023). Annual Change in Refraction The mean cycloplegic refraction of 23 of the patients (46 eyes), who were examined at yearly intervals for at least five years, were included in the study. To verify the natural course of hyperopia in accommodative esotropia, the total spherical equivalent change of each eye over the one-year interval during five years of follow-up was documented. Mean hyperopic change per year was analyzed by the Friedman test and reduction in hyperopia per year for both eyes was found statistically significant (P ⫽ .001). The age at first refraction, interval to last included refraction, initial spherical equivalent hypermetropia, and annual change in hypermetropia are shown in Table 2. Direction of change in hypermetropia was studied in 118 eyes (59 patients) who had at least 3 years follow-up. Of these hyperopic eyes, 21 (17.8%) experienced an increase, 66 (55.9%) a decrease, and 31 (26.3%) had no change. For those with a follow-up period of 5 years (46 eyes), 6 (13%) experienced an increase, 37 (80.5%) experienced a decrease, and 3 (6.5%) experienced no change. These results, which indicate that the trend towards decreasing hypermetropia was apparent, averaging ⫺0.16 ⫾ 2.0 D in 80.5% of the patients with at least five years follow-up are summarized in Table 3. Consecutive Exotropia Exotropia developed in eight patients following correction of their hyperopia. The mean age of development of exo-
TABLE 4. Comparison of the clinical features of early onset and control group Early Onset Group Control P (Under 12 mo.) Group Value Age at onset (mo) Age at initiation of treatment (mo) Cyclopegic refraction OD OS Angle of deviation Distance (pd) Near Number with amblyopia at diagnosis Number with measurable stereoacuity Number with measurable fusion Family history
N: 25 5.3 22.92
N: 122 44.79 51.69
0.0001* 0.0001*
⫹5.45
⫹4.83
0.109*
⫹5.16 27.18 26.84 14/25 (56%)
⫹4.78 22.56 24.28 73/122 (59%)
12/20 (60%)
73/103 (70.8%)0.730†
16/20 (80%)
91/116 (78.4%)1.000‡
6/25 (24%)
25/122 (20.4%)0.902†
0.335* 0.123* 0.297* 0.894†
*: Mann Whitney U test; †: 2 test; ‡: Fisher exact test; MO: month; OD: right eye; OS: left eye.
tropia was 98.25 ⫾ 27.20 months (range, 66 to 144 months). These patients had initially responded well to hyperopic correction but subsequently deteriorated an average 67.50 ⫾ 34.05 months (range, 18 to 126 months) after beginning therapy. When consecutive exotropia was first detected, only one patient in this group had amblyopia in the deviating eye. The mean refractive error of these patients was ⫹4.53 ⫾ 1.9 diopters (range, ⫹2.5 to ⫹8.0 D). Five patients had to be undercorrected to prevent exotropia development and glasses were eventually discontinued in three patients of the five because of an exotropia. One patient deteriorated into large angle exotropia with intractable diplopia that required surgery two years after the cessation of the hyperopic eyeglasses. Onset of Esotropia Before One Year of Age Twenty-five children with onset of refractive accommodative esotropia before they were one year old were evaluated to determine whether their outcomes and characteristics were different from those of patients with a more typical age (2 to 3 years old) at onset of esotropia. The remaining group were reviewed as controls (see Table 4) using the 2, Mann Whitney U, and Fisher’s exact tests. Both cycloplegic refraction and angle of deviation were greater in the early onset esotropia group, but not to statistical significance. On the other hand, incidence of amblyopia and binocular status at the last examination did not show any difference between the two groups.
DISCUSSION Amblyopia is often present, indeed characteristic of patients with accommodative esotropia, especially when the deviation has become constant. Swan6 reported 39 adults
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followed for more than 20 years. While 24 of the 39 (61.5%) were amblyopic in the deviating eye at the initial examination, at the most recent examination 25% were still amblyopic. In the study by Mulvihill et al7 only 41 children (of a sample of 103) had the pure accommodative esotropia which fulfilled our inclusion criteria. The remaining patients were partially accommodative and amblyopia developed in 61.2% of the patients. At last examination, 15.5% of the total had vision 20/40 or worse in their amblyopic eye. Anisometropia was significantly more likely to be present in amblyopic children in their study. In the present study 59.2% of the patients had amblyopia at the time of the initial examination, which is in accordance with the previous studies. The interval between mean age at onset of strabismus and initiation of treatment was shorter in the nonamblyopic group, and the mean cycloplegic refraction was lower in the nonamblyopic group, but these factors were not statistically significant. Anisometropia was the only statistically significant risk factor for the development of amblyopia, consistent with other studies. Substantial reduction in amblyopia from 59.2% to 23% was achieved at last follow-up. Amblyopia treatment with patching and close monitoring of the patients’ refractive changes were effective. Most children with accommodative esotropia should have a favorable prognosis for binocularity since the deviation usually develops after age two. Baker and Parks3 noted that many patients with accommodative esotropia developed monofixation syndrome if their binocular fusion was interrupted for a few weeks. Wilson et al5 found bifixation present in 24% of patients. Patients who had stereopsis at 50 sec/arc or better were defined as bifixator. They were less likely to have received patching or bifocals for amblyopia, progressed from intermittent to constant esotropia, and had less than 8 PD of esodeviation in their first glasses. Swan6 emphasized the importance of intervention prior to the development of a constant esotropia. Of 39 patients, only 10 (25%) had good binocular vision presumably when they were treated before development of a constant esotropia. In our study, 67.7% of patients had measurable stereoacuity at their latest follow-up but only 24% of them had 100 sec/arc or better stereoacuity, despite appropriate glasses and well-aligned eyes. Our data about the intermittancy period were not sufficient to make definitive statements about its effect on outcome of binocular status. Mazow et al8 could not find a correlation between the interval from onset of strabismus to the first glasses and the risk of developing amblyopia or reduced stereoacuity. Wilson et al5 also could not document a statistically significant difference between bifixators and monofixation patients for the same parameters. They concluded that this lack of correlation resulted from a tendency of accommodative esotropia to remain intermittent for long periods in some patients, while it progressed rapidly to constant esotropia in others. On the other hand, in the study by Mulvihill et al7 all children with fully
Berk, Koc¸ak, and Ellidokuz TABLE 5. Clinical features of early onset group Coats Baker and et al11 Parks3 (n ⴝ 11) (n ⴝ 17) Mean age at onset (months) Mean refractive error (diopters)* Number with amblyopia at diagnosis (%) Percent with measurable stereo acuity (last follow-up examination)
4.6
387
Current Study (n ⴝ 22)
3.9
5.3
⫹4.5
⫹4.69
⫹5.16
8/11 (73)
0/17 (0)
14/25 (56)
89
60
*Spherical equivalent of the least hyperopic eye.
refractive accommodative deviations had binocular vision. Thirty-seven out of 41 (90.2%) of these patients had stereopsis of 100 sec/arc or better. Such a discrepancy between studies indicates the need for more research to determine which factors are more likely to affect stereoacuity. In the present study, 73.5% of the patients had fusion with the Worth 4-dot test, and age at onset deviation was significantly higher in these patients. Later presentation strongly affected the fusional ability in our patients, though it had no effect on stereoacuity. Although accommodation was once considered not to begin functioning until 1 year of age, Haynes et al9 showed that accommodation may reach the adult level by the fourth month of life. Pollard10 described two patients with onset of esotropia at age 4.5 and 5 months who were found to have a large degree of hyperopia and their clinical features were similar to those of older patients with diagnosis of accommodative esotropia. Clinical features of these patients less than one year old compared with other studies are summarized in Table 5. The clinical characteristics of our early onset group were compared with those who had a more typical age at onset; both cycloplegic refraction and mean angle of deviation of the early onset group were found to be greater than the control group, but this was not statistically significant. We found no significant difference between these two groups for their outcomes. Fifty-six percent of the early onset group had amblyopia at the initial examination, 60% had measurable stereoacuity, and 80% developed fusion at last follow-up, whereas the controls had 59%, 70.8%, and 78.4%, respectively. These data support the finding that clinical features and outcomes of early onset patients are comparable to those of more typical age of onset; optical correction should be tried in all patients when the amount of hyperopia exceeds ⫹3.0 D, even if the child is less than 12 months old. Our findings with respect to binocularity and amblyopia further confirm the findings of Baker and Parks3, who reported that the risk of amblyopia was greater than 50% in early onset patients.
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In the present study, consecutive exotropia developed in 8 patients (5.4%) an average of 5.5 years after institution of full cycloplegic optical correction, though only one patient had amblyopia at initiation of therapy. To stimulate accommodative convergence the hyperopic corrections were reduced and patients chiefly controlled their deviation. Only one patient, who experienced diplopia 2 years after discontinuation of the spectacles, needed a surgery. If the patients have the risk of development of consecutive exotropia, we intentionally decrease the hyperopic corrections to stimulate accommodative convergence and control their deviation without disturbing their visual acuity. We try to attempt to reduce the hyperopic corrections 0.5 D stepwise intervals without decreasing the visual quality and without manifesting their esotropias. None of our children were able to discard their glasses. Swan6 reported six patients (15.3%) who developed exotropia in long-term follow-up. Contrary to our findings, all had amblyopia in one eye, reductions in spectacle corrections had no effect on outcome, and all eventually required surgery. In another study 18.4% of the patients developed consecutive exotropia seven years after beginning treatment. Amblyopia at the initial visit was significantly higher in their study population. They concluded that some children with fully refractive accommodative esotropia associated with amblyopia at the age of 3 or 4 years might be predisposed to develop consecutive exotropia.12 These patients should be followed throughout their lives, as development of exotropia resulting from diminished accommodative ability is likely, and its incidence of occurrence increases with time. To find out the natural tendency of hyperopia in accommodative esotropia, we studied 118 eyes and 46 eyes who had at least 3 and 5 years follow-up, respectively. At 3 years follow-up, hyperopia decreased in 55.9%, increased in 17.8%, and did not change for 26.3%. For those with 5 years of follow-up hyperopia decreased in 80.5%, increased in 13%, and in 6.5% remained the same. The mean hyperopic change per year in the 5 years follow-up group was documented and slow reduction in hyperopia was observed.
CONCLUSION Accommodative esodeviation, although typically commencing after age one year, can be observed as early as 4
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months of age, with similar clinical features and outcomes of older patients. We recommend cycloplegic refraction for all patients with suspected accommodative esotropia regardless of age. Amblyopia is a commonly associated finding, especially when the deviation is constant, and anisometropia is the only statistically significant factor that contributes to its development. Most of the patients developed good fusion but poor stereopsis. Approximately one fourth of patients enjoyed the quality of bifixation. All the patients we studied continued to require their hyperopic refraction even though the amount of hyperopia had lessened in magnitude. Most did not outgrow their hyperopia. In some patients prescription of full cycloplegic refraction resulted in diminished accommodative convergence ability, with development of subsequent exotropia during the long-term follow-up. Therefore, close monitoring is needed to make corrections in the glasses to control the deviation. References 1. Raab EL. Etiologic factors in accommodative esodeviation. Tr Am Ophth Soc Vol LXXX, 1982:657-94. 2. Preslan MW, Beauchomp GR. Accommodative esotropia: review of current practices and controversies. Ophthalmic Surg 1987;18:68-72. 3. Baker JD, Parks MM. Early-onset accommodative esotropia. Am J Ophthalmol 1980;90:11-8. 4. Parks MM. Abnormal accommodative convergence in squint. Arch Ophthalmol 1958;59:364-80. 5. Wilson ME, Bluestein EC, Parks MM. Binocularity in accommodative esotropia. J Pediatr Ophthalmol Strabismus 1993;30:233-6. 6. Swan KC. Accommodative esotropia long range follow-up. Ophthalmology 1983;90:1141-5. 7. Mulvihill A, MacCann A, Flitcroft I, O’Keefe M. Outcome in refractive accommodative esotropia. Br J Ophthalmol 2000;84:746-9. 8. Mazow ML, Kaldis LC, Prager TC. An evaluation of accommodative esotropia. In: Reinecke RD ed. Strabisbus II. New York: Grune and Stratton; 1984. pp.189-93. 9. Haynes H, White B, Held R. Visual accommodation in human infants. Science 1965;148:528-30. 10. Pollard ZF. Accommodative esotropia during the first year of life. Arch Ophthalmol 1976;64:1912-3. 11. Coats DK, Avilla CW, Paysse EA, Sprunger DT, Steinkuller PG, Somaiya M. Early-onset of refractive accommodative esotropia. J AAPOS 1998;2:275-8. 12. Watenable-Numata K, Hayasaka S, Watanabe K, Hayasaka Y, Kadoi C. Changes in deviation following correction of hyperopia in children with fully refractive accommodative esotropia. Ophthalmologica 2000;214:309-11.
A
From the Department of Ophthalmology,a,b and Department of Public Health,c Dokuz Eylul University, Y´zmir, Turkey. This study was partially presented at the Twelfth Congress of the European Society of Ophthalmology, June 2001, Istanbul, Turkey. Submitted December 2, 2002. Revisions accepted February 2, 2004. Reprint requests: A. Tu¨lin Berk, Huseyin Zeren Cad., Urla Berk Sitesi No: 143, Urla, Y´zmir, Turkey; e-mail: [email protected] Copyright © 2004 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2004/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2004.02.001
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METHODS AND MATERIALS We retrospectively reviewed the charts of 147 patients with accommodative refractive esotropia seen in our clinic between May 1992 and January 2001. There were 63 girls and 84 boys. For a diagnosis of refractive accommodative esotropia, patients had to have esotropia that was corrected to within 10 prism diopters (PD) of orthotropia at both distance and near with use of full cycloplegic hyperopic correction. Exclusion criteria included accommodative esotropia patients with high accommodative convergence/accommodation ratio, follow-up of 6 months or less, deteriorating accommodative esodeviation, history of developmental delay, and any form of neurologic impairment. All patients underwent a full ophthalmologic examination including orthoptic assessment, cycloplegic refraction, and binocular single vision, where cooperation was adequate. Binocular sensory testing was performed through the patient’s optimum hyperopic correction. Cycloplegia was accomplished with one drop of 1% cyclopentolate and 1% tropicamide, repeated in five to ten minutes, with retinoscopy performed after 60 minutes. Cycloplegia was repeated at least twice a year for all the study patients. The initial step in treatment was full correction of the hyperopia. As these patients had normal ratios of accomJournal of AAPOS
Journal of AAPOS Volume 8 Number 4 August 2004
modative convergence to accommodation, bifocals were not required. Occlusion was prescribed to treat amblyopia as soon as the effects of corrective lenses were established. An interocular difference of two or more Snellen lines was considered as amblyopic. Best-corrected visual acuity was measured using the Snellen chart where possible. The CSM (central, steady, maintained) was taken into account according to the bilateral fixation pattern in patients whose visual acuity could not be measured. Lack of alternate fixation and a strong unilateral objection to occlusion were considered diagnostic of amblyopia in the younger age group. Greater than 1.0 diopter difference between each eye was considered significant anisometropia. The onset of deviation was determined by family description and old photographs. The deviation with and without glasses was measured by the prism cover test in all cases. Ocular movements and convergence were evaluated. Stereoacuity was tested with TNO (Lame´ris Ootech, Groenekan, The Netherlands), Titmus fly test (Stereo Optical Co., Chicago, IL), and fusion with the Worth 4-dot test where cooperation was adequate. For purposes of our analyses, patients were divided into two groups, amblyopic (n ⫽ 87) and nonamblyopic (n ⫽ 60). To find out possible risk factors in the amblyopic group multiple parameters were reviewed, including sex, initial and final cycloplegic refractive error, distance and near deviation, stereoacuity, and time interval between onset of deviation and initiation of treatment. Twenty-five of the children had onset of refractive accommodative esotropia before 1 year old. Records of the 122 children with more typical age at onset of refractive accommodative esotropia were reviewed as controls for this subgroup. Clinical characteristics and treatment outcomes were compared between the two groups. The data were stored on a computerized database and analyzed using SPSS for Windows 8.0 (Statistical Package for Scientific Studies for Windows, SPSS Inc., Chicago, IL). Statistical analysis included the Mann Whitney U test, the Friedman two-way analysis of variance (ANOVA), the Wilcoxon, and the Student’s t tests where appropriate for continuous data, and the 2 and Fisher’s exact tests where appropriate for categorical data.
RESULTS The charts of one hundred forty-seven patients with accommodative esotropia were reviewed in the study. Thirty-nine patients with follow-up under 6 months were excluded from the final examination. The mean follow-up period was 43 months (range, 6 to 120 months; median 36). Amblyopia Eighty-seven (59.2%) of 147 patients were amblyopic at the time of initial examination. Mean age at onset of esodeviation, mean age at initiation of treatment, mean refractive error, mean angle of deviation with and without
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TABLE 1. Comparison based on amblyopia at the initial examination (the time of presentation) P Amblyopic Nonamblyopic Value Total number of patients 87 (59.2%) Mean age of onset (mo) 42.04 Mean age of initiation of treatment 53.07 (mo) Mean refractive error (diopters)* OD ⫹5.11 OS ⫹5.03 Mean deviation (pd without glasses) Distance 23.32 Near 24.79 Mean deviation (pd with glasses) Distance 2.78 Near 4.36 Anisometropia† (number of patients) 30 (34.5%)
60 (40.8%) 40.05 46.53
0.631 0.128
⫹4.50 ⫹4.44
0.053 0.063
22.27 23.17
0.639 0.415
3.35 4.95 7 (11.6%)
0.500 0.478 0.001
*Mean spherical equivalents; †Anisometropia: One diopter difference between right and left eye; PD: Prism diopters; MO: Month; OD: right eye; OS: left eye.
correction, and presence of anisometropia were compared between amblyopic and nonamblyopic groups to find out the possible risk factors (using the t test and 2). Results are summarized in Table 1. The interval between onset of strabismus and initiation of treatment was shorter in the nonamblyopic group, but this did not result in statistical significance (P ⫽ .05). Also, the mean cycloplegic refractive error was lower in the nonamblyopic group, but it was not statistically significant. Anisometropia was found to be the only statistically significant risk factor for the development of amblyopia in patients with accommodative refractive esotropia (P ⫽ .001). Treatment with occlusion was conducted in all amblyopic patients and none of the patients were noncompliant for both patching and wearing glasses. At the most recent examination, 15 (23%) of 65 amblyopic patients (22 were lost to follow-up) still had 20/40 or worse visual acuity in their amblyopic eye. Sixty-three percent of the patients reached equal visual acuity in both eyes by the end of occlusion treatment. Binocular Status Stereoacuity measurements were available at the end of the spectacle wear for 124 study patients, and ranged from zero to 40 sec/arc, with 84 of 124 patients (67.7 %) having measurable stereoacuity. Stereoacuity measurements were not available for the other patients because of young age, poor cooperation, or lack of documentation. While 24.2% (n ⫽ 30) of these patients have stereoacuity between 40 and 100 sec/arc, 20.96% (n ⫽ 26) of patients have 200 to 800 sec/arc and 22.58% (n ⫽ 28) of patients have 1980 to 3000 sec/arc; the remaining 32.26% (n ⫽ 40) had no stereoacuity. The ANOVA test revealed that two factors, age at onset of esodeviation (P ⫽ .271) and initiation of treatment (P ⫽ .645), had no effect on the outcome of stereoacuity.
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Journal of AAPOS Volume 8 Number 4 August 2004
Berk, Koc¸ak, and Ellidokuz
TABLE 2. Changes in hyperopia Number of Patients Number of eyes Initial refraction (diopters) Observation interval (month) Annual change in hyperopia
23*
59†
46 4.79 ⫾ 1.54 D (1.00–7.62 D) 79.1 ⫾ 17.8 mo ⫺0.16 ⫾ 0.20 D
118 4.44 ⫾ 1.75 D (1.00–8.0 D) 61.2 ⫾ 23.8 mo ⫺0.15 ⫾ 0.33 D
*: Patients who had at least 5 years follow-up; †: Patients who had at least 3 years follow-up; mo: month
TABLE 3. Direction of change in hypermetropia Number of Patients Number of eyes Increase Decrease Same
>5 Years Follow-Up (n ⴝ 23) 46 6 37 3
%
<3 Years Follow-Up (n ⴝ 59)
%
13.0 80.5 6.5
118 21 66 31
17.8 55.9 26.3
Fusion was evaluated in 135 patients. One hundred eight patients (108) had fusion, based on the Worth 4-dot test (73.5%). Age at onset of deviation was significantly higher in patients with fusion (P ⫽ .031) while age at initiation of treatment had no positive effect on development of fusion (P ⫽ .850). If the age of onset of deviation was greater than 24 months the likelihood of having fusion was higher in our study population (P ⫽ .023). Annual Change in Refraction The mean cycloplegic refraction of 23 of the patients (46 eyes), who were examined at yearly intervals for at least five years, were included in the study. To verify the natural course of hyperopia in accommodative esotropia, the total spherical equivalent change of each eye over the one-year interval during five years of follow-up was documented. Mean hyperopic change per year was analyzed by the Friedman test and reduction in hyperopia per year for both eyes was found statistically significant (P ⫽ .001). The age at first refraction, interval to last included refraction, initial spherical equivalent hypermetropia, and annual change in hypermetropia are shown in Table 2. Direction of change in hypermetropia was studied in 118 eyes (59 patients) who had at least 3 years follow-up. Of these hyperopic eyes, 21 (17.8%) experienced an increase, 66 (55.9%) a decrease, and 31 (26.3%) had no change. For those with a follow-up period of 5 years (46 eyes), 6 (13%) experienced an increase, 37 (80.5%) experienced a decrease, and 3 (6.5%) experienced no change. These results, which indicate that the trend towards decreasing hypermetropia was apparent, averaging ⫺0.16 ⫾ 2.0 D in 80.5% of the patients with at least five years follow-up are summarized in Table 3. Consecutive Exotropia Exotropia developed in eight patients following correction of their hyperopia. The mean age of development of exo-
TABLE 4. Comparison of the clinical features of early onset and control group Early Onset Group Control P (Under 12 mo.) Group Value Age at onset (mo) Age at initiation of treatment (mo) Cyclopegic refraction OD OS Angle of deviation Distance (pd) Near Number with amblyopia at diagnosis Number with measurable stereoacuity Number with measurable fusion Family history
N: 25 5.3 22.92
N: 122 44.79 51.69
0.0001* 0.0001*
⫹5.45
⫹4.83
0.109*
⫹5.16 27.18 26.84 14/25 (56%)
⫹4.78 22.56 24.28 73/122 (59%)
12/20 (60%)
73/103 (70.8%)0.730†
16/20 (80%)
91/116 (78.4%)1.000‡
6/25 (24%)
25/122 (20.4%)0.902†
0.335* 0.123* 0.297* 0.894†
*: Mann Whitney U test; †: 2 test; ‡: Fisher exact test; MO: month; OD: right eye; OS: left eye.
tropia was 98.25 ⫾ 27.20 months (range, 66 to 144 months). These patients had initially responded well to hyperopic correction but subsequently deteriorated an average 67.50 ⫾ 34.05 months (range, 18 to 126 months) after beginning therapy. When consecutive exotropia was first detected, only one patient in this group had amblyopia in the deviating eye. The mean refractive error of these patients was ⫹4.53 ⫾ 1.9 diopters (range, ⫹2.5 to ⫹8.0 D). Five patients had to be undercorrected to prevent exotropia development and glasses were eventually discontinued in three patients of the five because of an exotropia. One patient deteriorated into large angle exotropia with intractable diplopia that required surgery two years after the cessation of the hyperopic eyeglasses. Onset of Esotropia Before One Year of Age Twenty-five children with onset of refractive accommodative esotropia before they were one year old were evaluated to determine whether their outcomes and characteristics were different from those of patients with a more typical age (2 to 3 years old) at onset of esotropia. The remaining group were reviewed as controls (see Table 4) using the 2, Mann Whitney U, and Fisher’s exact tests. Both cycloplegic refraction and angle of deviation were greater in the early onset esotropia group, but not to statistical significance. On the other hand, incidence of amblyopia and binocular status at the last examination did not show any difference between the two groups.
DISCUSSION Amblyopia is often present, indeed characteristic of patients with accommodative esotropia, especially when the deviation has become constant. Swan6 reported 39 adults
Journal of AAPOS Volume 8 Number 4 August 2004
followed for more than 20 years. While 24 of the 39 (61.5%) were amblyopic in the deviating eye at the initial examination, at the most recent examination 25% were still amblyopic. In the study by Mulvihill et al7 only 41 children (of a sample of 103) had the pure accommodative esotropia which fulfilled our inclusion criteria. The remaining patients were partially accommodative and amblyopia developed in 61.2% of the patients. At last examination, 15.5% of the total had vision 20/40 or worse in their amblyopic eye. Anisometropia was significantly more likely to be present in amblyopic children in their study. In the present study 59.2% of the patients had amblyopia at the time of the initial examination, which is in accordance with the previous studies. The interval between mean age at onset of strabismus and initiation of treatment was shorter in the nonamblyopic group, and the mean cycloplegic refraction was lower in the nonamblyopic group, but these factors were not statistically significant. Anisometropia was the only statistically significant risk factor for the development of amblyopia, consistent with other studies. Substantial reduction in amblyopia from 59.2% to 23% was achieved at last follow-up. Amblyopia treatment with patching and close monitoring of the patients’ refractive changes were effective. Most children with accommodative esotropia should have a favorable prognosis for binocularity since the deviation usually develops after age two. Baker and Parks3 noted that many patients with accommodative esotropia developed monofixation syndrome if their binocular fusion was interrupted for a few weeks. Wilson et al5 found bifixation present in 24% of patients. Patients who had stereopsis at 50 sec/arc or better were defined as bifixator. They were less likely to have received patching or bifocals for amblyopia, progressed from intermittent to constant esotropia, and had less than 8 PD of esodeviation in their first glasses. Swan6 emphasized the importance of intervention prior to the development of a constant esotropia. Of 39 patients, only 10 (25%) had good binocular vision presumably when they were treated before development of a constant esotropia. In our study, 67.7% of patients had measurable stereoacuity at their latest follow-up but only 24% of them had 100 sec/arc or better stereoacuity, despite appropriate glasses and well-aligned eyes. Our data about the intermittancy period were not sufficient to make definitive statements about its effect on outcome of binocular status. Mazow et al8 could not find a correlation between the interval from onset of strabismus to the first glasses and the risk of developing amblyopia or reduced stereoacuity. Wilson et al5 also could not document a statistically significant difference between bifixators and monofixation patients for the same parameters. They concluded that this lack of correlation resulted from a tendency of accommodative esotropia to remain intermittent for long periods in some patients, while it progressed rapidly to constant esotropia in others. On the other hand, in the study by Mulvihill et al7 all children with fully
Berk, Koc¸ak, and Ellidokuz TABLE 5. Clinical features of early onset group Coats Baker and et al11 Parks3 (n ⴝ 11) (n ⴝ 17) Mean age at onset (months) Mean refractive error (diopters)* Number with amblyopia at diagnosis (%) Percent with measurable stereo acuity (last follow-up examination)
4.6
387
Current Study (n ⴝ 22)
3.9
5.3
⫹4.5
⫹4.69
⫹5.16
8/11 (73)
0/17 (0)
14/25 (56)
89
60
*Spherical equivalent of the least hyperopic eye.
refractive accommodative deviations had binocular vision. Thirty-seven out of 41 (90.2%) of these patients had stereopsis of 100 sec/arc or better. Such a discrepancy between studies indicates the need for more research to determine which factors are more likely to affect stereoacuity. In the present study, 73.5% of the patients had fusion with the Worth 4-dot test, and age at onset deviation was significantly higher in these patients. Later presentation strongly affected the fusional ability in our patients, though it had no effect on stereoacuity. Although accommodation was once considered not to begin functioning until 1 year of age, Haynes et al9 showed that accommodation may reach the adult level by the fourth month of life. Pollard10 described two patients with onset of esotropia at age 4.5 and 5 months who were found to have a large degree of hyperopia and their clinical features were similar to those of older patients with diagnosis of accommodative esotropia. Clinical features of these patients less than one year old compared with other studies are summarized in Table 5. The clinical characteristics of our early onset group were compared with those who had a more typical age at onset; both cycloplegic refraction and mean angle of deviation of the early onset group were found to be greater than the control group, but this was not statistically significant. We found no significant difference between these two groups for their outcomes. Fifty-six percent of the early onset group had amblyopia at the initial examination, 60% had measurable stereoacuity, and 80% developed fusion at last follow-up, whereas the controls had 59%, 70.8%, and 78.4%, respectively. These data support the finding that clinical features and outcomes of early onset patients are comparable to those of more typical age of onset; optical correction should be tried in all patients when the amount of hyperopia exceeds ⫹3.0 D, even if the child is less than 12 months old. Our findings with respect to binocularity and amblyopia further confirm the findings of Baker and Parks3, who reported that the risk of amblyopia was greater than 50% in early onset patients.
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In the present study, consecutive exotropia developed in 8 patients (5.4%) an average of 5.5 years after institution of full cycloplegic optical correction, though only one patient had amblyopia at initiation of therapy. To stimulate accommodative convergence the hyperopic corrections were reduced and patients chiefly controlled their deviation. Only one patient, who experienced diplopia 2 years after discontinuation of the spectacles, needed a surgery. If the patients have the risk of development of consecutive exotropia, we intentionally decrease the hyperopic corrections to stimulate accommodative convergence and control their deviation without disturbing their visual acuity. We try to attempt to reduce the hyperopic corrections 0.5 D stepwise intervals without decreasing the visual quality and without manifesting their esotropias. None of our children were able to discard their glasses. Swan6 reported six patients (15.3%) who developed exotropia in long-term follow-up. Contrary to our findings, all had amblyopia in one eye, reductions in spectacle corrections had no effect on outcome, and all eventually required surgery. In another study 18.4% of the patients developed consecutive exotropia seven years after beginning treatment. Amblyopia at the initial visit was significantly higher in their study population. They concluded that some children with fully refractive accommodative esotropia associated with amblyopia at the age of 3 or 4 years might be predisposed to develop consecutive exotropia.12 These patients should be followed throughout their lives, as development of exotropia resulting from diminished accommodative ability is likely, and its incidence of occurrence increases with time. To find out the natural tendency of hyperopia in accommodative esotropia, we studied 118 eyes and 46 eyes who had at least 3 and 5 years follow-up, respectively. At 3 years follow-up, hyperopia decreased in 55.9%, increased in 17.8%, and did not change for 26.3%. For those with 5 years of follow-up hyperopia decreased in 80.5%, increased in 13%, and in 6.5% remained the same. The mean hyperopic change per year in the 5 years follow-up group was documented and slow reduction in hyperopia was observed.
CONCLUSION Accommodative esodeviation, although typically commencing after age one year, can be observed as early as 4
Journal of AAPOS Volume 8 Number 4 August 2004
months of age, with similar clinical features and outcomes of older patients. We recommend cycloplegic refraction for all patients with suspected accommodative esotropia regardless of age. Amblyopia is a commonly associated finding, especially when the deviation is constant, and anisometropia is the only statistically significant factor that contributes to its development. Most of the patients developed good fusion but poor stereopsis. Approximately one fourth of patients enjoyed the quality of bifixation. All the patients we studied continued to require their hyperopic refraction even though the amount of hyperopia had lessened in magnitude. Most did not outgrow their hyperopia. In some patients prescription of full cycloplegic refraction resulted in diminished accommodative convergence ability, with development of subsequent exotropia during the long-term follow-up. Therefore, close monitoring is needed to make corrections in the glasses to control the deviation. References 1. Raab EL. Etiologic factors in accommodative esodeviation. Tr Am Ophth Soc Vol LXXX, 1982:657-94. 2. Preslan MW, Beauchomp GR. Accommodative esotropia: review of current practices and controversies. Ophthalmic Surg 1987;18:68-72. 3. Baker JD, Parks MM. Early-onset accommodative esotropia. Am J Ophthalmol 1980;90:11-8. 4. Parks MM. Abnormal accommodative convergence in squint. Arch Ophthalmol 1958;59:364-80. 5. Wilson ME, Bluestein EC, Parks MM. Binocularity in accommodative esotropia. J Pediatr Ophthalmol Strabismus 1993;30:233-6. 6. Swan KC. Accommodative esotropia long range follow-up. Ophthalmology 1983;90:1141-5. 7. Mulvihill A, MacCann A, Flitcroft I, O’Keefe M. Outcome in refractive accommodative esotropia. Br J Ophthalmol 2000;84:746-9. 8. Mazow ML, Kaldis LC, Prager TC. An evaluation of accommodative esotropia. In: Reinecke RD ed. Strabisbus II. New York: Grune and Stratton; 1984. pp.189-93. 9. Haynes H, White B, Held R. Visual accommodation in human infants. Science 1965;148:528-30. 10. Pollard ZF. Accommodative esotropia during the first year of life. Arch Ophthalmol 1976;64:1912-3. 11. Coats DK, Avilla CW, Paysse EA, Sprunger DT, Steinkuller PG, Somaiya M. Early-onset of refractive accommodative esotropia. J AAPOS 1998;2:275-8. 12. Watenable-Numata K, Hayasaka S, Watanabe K, Hayasaka Y, Kadoi C. Changes in deviation following correction of hyperopia in children with fully refractive accommodative esotropia. Ophthalmologica 2000;214:309-11.