Long-term treatment results of accommodative esotropia Kanwar Mohan, MS,a and Ashok Sharma, MSb PURPOSE METHODS
RESULTS
CONCLUSIONS
To report the long-term ocular alignment outcomes of patients with accommodative esotropia. The medical records of consecutive patients #12 year of age diagnosed with refractive accommodative esotropia (esotropia eliminated or decreased to within 10D with full hyperopic correction) and followed for at least 10 years were retrospectively reviewed. A total of 107 patients were included (mean age, 4.81 2.64 years). The mean follow-up period was 12.02 2.25 years (range, 10-21 years). At the first examination performed 10 years after spectacle correction (mean, 10.2 years), 85 patients (79%) had orthophoria or esotropia #10D at both near and distance fixation, 14 (13%) had consecutive exotropia, 5 (5%) had decompensation and 3 (3%) had esotropia with a high ratio of accommodative convergence to accommodation (AC/A). The mean time interval between presentation and prescription of full hyperopic correction, initial cycloplegic refraction, and presence of amblyopia was not associated with consecutive exotropia, decompensation, or a high AC/A ratio esotropia. Whereas most patients with refractive accommodative esotropia maintained normal longterm ocular motility with spectacle treatment, some developed consecutive exotropia, nonaccommodative esotropia, or esotropia with a high AC/A ratio. ( J AAPOS 2014;18: 261-265)
A
ccommodative esotropia is common in young children and is conventionally treated with full cycloplegic hyperopic correction. After successful alignment of the eyes, accommodative esotropia may take one of the following courses: (1) the eyes may remain aligned, (2) esotropia may decompensate, or (3) esotropia may spontaneously convert to consecutive exotropia. Most studies on treatment outcomes of accommodative esotropia have included patients with either a high ratio of accommodative convergence to accommodation (AC/A)1-6 or with a partially accommodative esotropia.7,8 Few studies9-12 have reported on status of ocular alignment of exclusively an accommodative esotropia. To our knowledge, only one study has reported all three outcomes,10 and none has reported the development of high AC/A ratio esotropia in patients with previously controlled accommodative esotropia. Minimum followup in these studies ranges from 6 months to 7 years10-12; in one study of adults who had refractive accommodative esotropia in early childhood, patients were reexamined at intervals of 20 or more years.9 In only one study were all
Author affiliations: aSquint Centre, Chandigarh, India; bCornea Centre, Chandigarh, India Submitted July 17, 2013. Revision accepted January 13, 2014. Correspondence: Kanwar Mohan, MS, Squint Centre, SCO : 833-834 (2nd floor), Sector 22-A, Chandigarh – 160022, India (email: [email protected]). Copyright Ó 2014 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2014.01.018
Journal of AAPOS
pretreatment, treatment, and post-treatment examinations performed by the same investigator.9 The purpose of the present study was to report ocular alignment outcomes in patients with refractive accommodative esotropia only who were initially examined, treated, and followed by the same investigator, with a minimum follow-up of 10 years.
Subjects and Methods This study was approved by the Squint Centre Institutional Review Board and complied with the tenets of the Declaration of Helsinki. The medical records of consecutive patients diagnosed with refractive accommodative esotropia at the Squint Centre, Chandigarh, between January 1990 and March 2003 were retrospectively reviewed. Refractive accommodative esotropia was diagnosed if esotropia was eliminated or decreased to within 10D at both near and distance with full cycloplegic hyperopic correction on the first follow-up at least 1 month after the prescription of spectacles. We prescribed full cycloplegic hyperopic correction initially to all patients. Full hyperopic correction was continued if there was orthophoria/esotropia #10D and good visual acuity at the first follow-up. If a patient did not tolerate full correction and had a more than one Snellen line decrease in visual acuity, hyperopic correction was reduced by 0.50–1.0 D to improve visual acuity without affecting alignment status. If reduction of hyperopic correction improved the visual acuity but adversely affected the alignment, atropine instillation once a day for 1 week was prescribed to relax accommodation, and the patient was encouraged to wear full correction. At the 6 month follow-up and annually thereafter, if the patient had no visual
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complaints, good visual acuity, and orthophoria or esotropia of #10D for 2-3 consecutive years, spectacles were undercorrected by 0.50 D to 1.0 D, respectively, depending upon whether cyclopentolate or atropine was used for cycloplegic refraction. If exotropia was observed at any follow-up examination, hyperopic correction was reduced to control exotropia. Full astigmatic refractive correction was prescribed throughout the follow-up. This strategy was uniform for all patients. All patients were followed for at least 10 years. All baseline examinations, treatment, and follow-up examinations were performed by one investigator (KM). Patients who were older than 12 years at presentation, had accommodative esotropia with high AC/A ratio or partially accommodative esotropia, previous extraocular muscle surgery, restricted ocular movements, developmental delay, or neurological disorder were excluded. Patients with coexisting vertical deviation and oblique dysfunctions were not excluded. The following data were collected: age at presentation, age at prescription of full cycloplegic hyperopic correction, bestcorrected visual acuity, measurement of deviation at near and at distance with glasses, and cycloplegic refraction. Ocular alignment was assessed using the prism and alternate cover test in older children and the modified Krimsky test in younger children. Best-corrected visual acuity was measured using the Snellen chart in older children and by binocular fixation pattern in younger patients. Amblyopia was defined as a difference of 2 or more Snellen lines between the best-corrected visual acuity of the two eyes. Lack of alternate fixation in the cover–uncover test was considered diagnostic of amblyopia in younger patients. Cycloplegic refraction was performed after instillation of atropine 1% twice a day for 3 days in children #10 years of age and after 3 instillations of cyclopentolate 1% in those .10 years. Refraction was performed using hand held lenses in uncooperative children and autorefractor (Huvitz, MR-3100 P, Korea) in cooperative children. We repeated cycloplegic refraction on subsequent follow-ups at interval of 6 months in younger patients and 1 year in older patients, as suggested by Dale.13 The spherical equivalent refractive error was calculated as sum of the sphere and one half of the cylinder power. The mean spherical equivalent of the less hyperopic eye or the eye preferred for fixation if both eyes had the same hypermetropia was used for statistical analysis. Anisometropia was defined as a difference of 1.5 D or more in the spherical equivalent refractive error between eyes. Decompensation was defined as an increase of a previously controlled esotropia to .10D both at distance and at near. Any amount of exotropia at near and/or at distance with spectacles was diagnosed consecutive exotropia. High AC/A ratio esotropia was diagnosed if esotropia at near fixation was at least 10D greater than that at distance fixation with full hyperopic correction in place and the AC/A ratio was more than 5:1 by the lens gradient method.14 Statistical analysis was performed using the t test, the Z test for proportions, and the c2 test. Cumulative probability of orthophoria or esotropia of #10D at various follow-ups was determined by Kaplan-Meier survival analysis. A P value of \0.05 was considered statistically significant.
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Results A total of 107 patients (57 males [53%]) met inclusion criteria. The mean age plus or minus standard deviation at presentation was 4.81 2.64 years (range, 8 months12 years). The mean time interval between presentation and prescription of full cycloplegic hyperopic correction was 0.35 1.13 years (range, 0-7 years). Of the 107 patients, 35 (32.7%) had amblyopia (strabismic, 28 [26.2%]; anisometropic, 7 [6.5%]) at the time of presentation. Two patients each had inferior oblique overaction and dissociated vertical deviation. The mean follow-up period was 12.02 2.25 years (range, 10-21 years). Patients were followed for at least 10 years (107 patients), 15 years (80 patients), 20 years (9 patients), and .20 years (2 patients). At the first examination performed 10 years (mean, 10.2 years) after prescription of glasses, 85 of 107 patients (79%) had orthophoria or esotropia #10D at both near and distance fixation, 14 (13%) had consecutive exotropia, 5 (5%) had decompensation, and 3 (3%) had a high AC/A ratio esotropia. Kaplan-Meier survival analysis demonstrated probabilities of orthophoria/esotropia #10D of 89% at 5 years, 80% at 10 years, and 71% at 15 years (Figure 1). The incidence of various ocular alignment outcomes at different follow-up intervals is shown in Figure 2. Overall, 80 patients (75%) had orthophoria or esotropia #10D at both near and distance at their mean follow-up of 11.62 1.71 years (range, 10-19 years), and 16 (15%) developed consecutive exotropia at a mean 6.70 2.59 years (range, 2.25-10.75 years), 8 (8%) had decompensation of a previously controlled esotropia at a mean 5.97 4.70 years (range, 0.75-12.00 years), and 3 (3%) developed a high AC/A ratio esotropia at a mean 2.56 2.71 years (range, 0.75-5.67 years) after prescription of full hyperopic correction. A modal distribution of the clinical features based on ocular alignment status at the first examination performed 10 years after prescription of glasses is presented in Table 1. There was no statistically significant difference in the mean time interval between presentation and prescription of full hyperopic correction, mean cycloplegic refraction, and presence of amblyopia between patients who developed consecutive exotropia and those who had orthophoria or esotropia #10D (P 5 0.86, P 5 0.45, and P 5 0.15, respectively). The patients with consecutive exotropia had a mean cycloplegic refractive error of 15.55 1.80 D (range, 12.50 to 18.50 D) at the time of prescription of full hyperopic correction and 15.28 1.69 D (range, 10.87 to 17.62 D) at the time of detection of consecutive exotropia, and this difference was not statistically significant (P 5 0.67). Of the 68 patients with \6.0 D hypermetropia, 7 (10.3%) developed consecutive exotropia, compared to 9 (23.1%) of the 39 patients with $6.0 D hypermetropia; this difference was not statistically significant (P 5 0.07). Consecutive exotropia was treated by reductions in hyperopic correction in 12
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There was no statistically significant difference in the mean time interval between presentation and prescription of full hyperopic correction, mean cycloplegic refraction, and presence of amblyopia between patients who developed a high AC/A ratio esotropia and those who had orthophoria or esotropia of #10D (P 5 0.58, P 5 0.43 and P 5 0.92, respectively). The mean cycloplegic refraction was 14.25 2.84 D (range, 12.25 to 17.50 D) at the time of prescription of full hyperopic correction and 14.17 2.70 D (range, 12.25 to 17.25 D) at the time of detection of high AC/A esotropia; this difference was not statistically significant (P 5 0.97).
Discussion
FIG 1. Cumulative probability of orthophoria or esotropia of #10D at various durations of follow-up.
FIG 2. The incidence of various ocular alignment outcomes at different follow-up intervals. The number of patients in each category appears above the bar.
of the 16 patients (75%), initial reductions followed by discontinuation of spectacles in 3 (19%), and strabismus surgery in 1 (6.2%) patients. There was no statistically significant difference in the mean time interval between presentation and prescription of full hyperopic correction, mean cycloplegic refraction, and presence of amblyopia between patients who had decompensation and those who had orthophoria or esotropia of #10D (P 5 0.48, P 5 0.70 and P 5 0.17, respectively). The patients with decompensation had a mean cycloplegic refractive error of 14.70 1.60 D (range, 12.50 to 17.00 D) at the time of prescription of full hyperopic correction and 14.72 1.62 D (range, 11.87 to 17.12 D) at the time of decompensation, and this difference was not statistically significant (P 5 0.99). One of our 2 patients who had inferior oblique overaction developed decompensation. Three patients exhibited a 19D-20D increase in esotropia on near fixation compared to that on distance fixation and had a high AC/A ratio (mean, 6.5:1; range, 6.3:1 to 6.6:1).
Journal of AAPOS
A comparison of various studies on refractive accommodative esotropia is difficult because of different definitions of refractive accommodative esotropia and different minimum durations of follow-up in these studies.2,4,10-12 Refractive accommodative esotropia was diagnosed if the deviation was either eliminated or reduced to within 10D at both near and distance fixation with full cycloplegic hyperopic correction.3 Long follow-up is necessary to evaluate the course of refractive accommodative esotropia after full hyperopic correction. We included patients with a minimum follow-up of 10 years. Watanabe-Numata and colleagues10 examined 49 children who had fully refractive accommodative esotropia at the age of 3 or 4 years and observed that 57% of these children had orthophoria or esotropia of #5D at the age of 10 or 11 years. Reddy and colleagues8 found \8D esotropia in 66% of their patients at a mean follow-up of 3 years, whereas von Noorden and Avilla12 reported orthophoria or small asymptomatic esophoria in 97% of the patients at an average follow-up of 7 years. We observed orthophoria or esotropia #10D in 75% of our patients throughout their mean follow-up of 11.6 years. Consecutive exotropia develops spontaneously in 5% to 15% of patients with refractive accommodative esotropia after a few weeks to an average 5.5 years of full hyperopic correction.9-11 This occurred in 15% of our patients, at a mean of 6.7 years after prescription of full hyperopic correction. Some investigators9,10 have found that amblyopia is a significant risk factor for the development of consecutive exotropia in patients with refractive accommodative esotropia. However, we did not find it to be a risk factor, as also observed by Moore.15 WatanabeNumata and colleagues10 did not find age at the start of hyperopic correction to be a risk factor, in agreement with the present study. Swan9 found that a reduction of hyperopic correction to stimulate accommodative convergence and control exotropia did not help and all patients who required surgery, whereas Watanabe-Numata and colleagues10 reported that 67% of their patients underwent extraocular muscle surgery. In contrast, Beneish and colleagues16 observed that 50% to 60% reduction in hyperopic correction resulted in a satisfactory realignment of
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Table 1. Modal distribution of the clinical features based on ocular alignment status at the first examination performed 10 years after prescription of spectacles Alignment status Clinical features
Orthophoria or esotropia #10D (n 5 85)
Consecutive exotropia (n 5 14)
0.37 1.16 0.00 3.94 16.49
0.43 1.24 0.00 3.20 10.56
5.14 1.91 5.25 0.11 0.81 26 (30.6)
5.55 1.67 4.00 0.33 0.16 7 (50.0)
Time from presentation to full hyperopic correction, years Mean SD Mode Skewness Kurtosis Initial cycloplegic refraction,a D Mean SD Mode Skewness Kurtosis Amblyopia, no. (%)
Decompensation (n 5 5)
0.00 0.00 0.00 0.00 5.47 1.42 4.00 0.19 2.90 3 (60.0)
High AC/A ratio esotropia (n 5 3)
0.00 0.00 0.00 0.00 4.25 2.84 2.25 1.60 — 1 (33.3)
D, diopters; SD, standard deviation. Spherical equivalent hypermetropia.
a
the eyes. Berk and colleagues11 also found that a reduction in hyperopic correction (with subsequent discontinuation of glasses in a few patients) was successful in 62% of their patients and strabismus surgery was required in only 12.5% of cases. In the present study, a large majority (94%) of the patients had control of exotropia with reduction of hyperopic correction; strabismus surgery was performed in only 6% of cases. Decompensation occurs in 2% to 12% of the patients with a previously controlled accommodative esotropia in general1-5,7 and in 13.5% to 33.0% of the patients with an exclusively refractive accommodative esotropia.4,10,12 We observed decompensation in 7.5% of our patients. The mean time at which decompensation occurs has varied from 3.8 years to 5 years.1,3,12 In our patients, decompensation was seen at a mean approximately 6 years after prescription of full hyperopic correction. The earliest time at which decompensation has been reported to occur has been 1 year after the diagnosis of refractive accommodative esotropia.3,4 By contrast, we noted decompensation as early as 9 months after full hyperopic correction. Some investigators found abnormal distance– near relationship,2 a high AC/A ratio,5 a moderate hypermetropia (2.75–4.0 D),1 oblique muscle dysfunction,2,5 amblyopia,5 a long delay between onset of esotropia and glasses prescription,1 failure to fully correct hypermetropia,2 and lack of compliance in glasses wear to be risk factors for decompensation; others did not find delay in treatment,5 severity of AC/A ratio,1 and refractive changes3 to be predictors of decompensation. The present study did not find mean time interval between presentation and prescription of full hyperopic correction, mean initial hypermetropia, and amblyopia to be risk factors for decompensation. Several investigators have reported that decompensation occurs despite hypermetropia remaining static,1,3 an observation borne out by our results. To our knowledge, the development of a high AC/A ratio esotropia in a previously well controlled refractive
accommodative esotropia has not been previously reported. We observed such a development in 3 of our patients at a mean follow-up of 2.5 years after prescription of full hyperopic correction. If a patient with a previously controlled refractive accommodative esotropia exhibits an increase in near esotropia of $10D while hypermetropia is static, a high AC/A ratio esotropia should be considered and the AC/A ratio should be measured using the lens gradient method to differentiate it from nonaccommodative convergence excess. Inferior oblique overaction is seen in 15% to 17% of patients with accommodative esotropia.6,17 However, von Noorden and Avilla12 reported that oblique dysfunction did not occur in refractive accommodative esotropia. Some investigators2,5 have found that decompensation was more common in patients who had inferior oblique overaction. Inferior oblique overaction was observed in only 2 of our patients; thus we cannot comment on the role inferior oblique overaction may play in decompensation. The measurement of a patient’s deviation may vary according to clinician experience and expertise, and inclusion of patients managed by different investigators can result in nonstandardized data. In that regard, the data in the present study is uniform because examinations were performed by the same investigator. Nevertheless, this study does have several limitations. First, the investigator was not masked to the findings of previous examinations; therefore, some element of bias in measurement of deviation cannot be ruled out. Second, AC/A ratio was not measured routinely. Hence, the role of AC/A ratio in decompensation cannot be evalutated. Third, we performed initial cycloplegic refraction using handheld lenses in uncooperative children and autorefractor during followups when these children were old enough and cooperative. Hence the refraction measurements may not be comparable. Fourth, sensory data was not reported. Finally, the follow-up period was not uniform for all patients.
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Literature Search A literature search was performed on PubMed using the following terms: accommodative esotropia, refractive accommodative esotropia, and high AC/A ratio esotropia.
Acknowledgments The authors thank Dr. Suresh Sharma, Department of Statistics, Punjab University, Chandigarh, for his statistical analysis of the study data. References 1. Dickey CF, Scott WE. Deterioration of accommodative esotropia: frequency, characteristics and predictive factors. J Pediatr Ophthalmol Strabismus 1988;25:172-5. 2. Black BC. The influence of refractive error management on the natural history and treatment outcome of accommodative esotropia. Trans Am Ophthalmol Soc 2006;104:303-21. 3. Raab EL. Monitoring of controlled accommodative esotropia. Trans Am Ophthalmol Soc 2001;99:225-31. 4. Mohney BG, Lilley CC, Green-Simms AE, Diehl NN. The long-term follow-up of accommodative esotropia in a populationbased cohort of children. Ophthalmology 2011;118:581-5. 5. Ludwig IH, Imberman SP, Thompson HW, Parks MM. Long-term study of accommodative esotropia. J AAPOS 2005;9:522-6. 6. Rutstein RP, Marsh-Tootle W. Clinical course of accommodative esotropia. Optom Vis Sci 1998;75:97-102.
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7. Mulvihill A, MacCann A, Flitcroft I, O’ Keefe M. Outcome in refractive accommodative esotropia. Br J Ophthalmol 2000;84:746-9. 8. Reddy AK, Freeman CH, Paysse EA, Coats DK. A data-driven approach to the management of accommodative esotropia. Am J Ophthalmol 2009;148:466-70. 9. Swan KC. Accommodative esotropia long range follow-up. Ophthalmology 1983;90:1141-5. 10. Watanabe-Numata K, Hayasaka S, Watanabe K, Hayasaka Y, Kadoi C. Changes in deviation following correction of hyperopia in children with fully accommodative esotropia. Ophthalmologica 2000;214:309-11. 11. Berk AT, Kocak N, Ellidokuz H. Treatment outcomes in refractive accommodative esotropia. J AAPOS 2004;384-8. 12. von Noorden GK, Avilla CW. Refractive accommodative esotropia : a surgical problem. Int Ophthalmol 1992;16:45-8. 13. Dale RT. Fundamentals of Ocular Motility and Strabismus. New York: Grune and Stratton, Inc; 1982:194. 14. Arnoldi KA, Tychsen L. Surgery for esotropia with a high accommodative convergence/accommodation ratio: effects on accommodative vergence and binocularity. Ophthalmic Surg Lasers 1996; 27:342-8. 15. Moore S. The natural history of esotropia. Am Orthopt J 1971;21: 80-83. 16. Beneish R, Williams F, Polomeno RC, Little JM. Consecutive exotropia after correction of hyperopia. Can J Ophthalmol 1981; 16:16-18. 17. Raab EL. Etiological factors in accommodative esodeviation. Trans Am Ophthalmol Soc 1982;80:657-94.
RESULTS
CONCLUSIONS
To report the long-term ocular alignment outcomes of patients with accommodative esotropia. The medical records of consecutive patients #12 year of age diagnosed with refractive accommodative esotropia (esotropia eliminated or decreased to within 10D with full hyperopic correction) and followed for at least 10 years were retrospectively reviewed. A total of 107 patients were included (mean age, 4.81 2.64 years). The mean follow-up period was 12.02 2.25 years (range, 10-21 years). At the first examination performed 10 years after spectacle correction (mean, 10.2 years), 85 patients (79%) had orthophoria or esotropia #10D at both near and distance fixation, 14 (13%) had consecutive exotropia, 5 (5%) had decompensation and 3 (3%) had esotropia with a high ratio of accommodative convergence to accommodation (AC/A). The mean time interval between presentation and prescription of full hyperopic correction, initial cycloplegic refraction, and presence of amblyopia was not associated with consecutive exotropia, decompensation, or a high AC/A ratio esotropia. Whereas most patients with refractive accommodative esotropia maintained normal longterm ocular motility with spectacle treatment, some developed consecutive exotropia, nonaccommodative esotropia, or esotropia with a high AC/A ratio. ( J AAPOS 2014;18: 261-265)
A
ccommodative esotropia is common in young children and is conventionally treated with full cycloplegic hyperopic correction. After successful alignment of the eyes, accommodative esotropia may take one of the following courses: (1) the eyes may remain aligned, (2) esotropia may decompensate, or (3) esotropia may spontaneously convert to consecutive exotropia. Most studies on treatment outcomes of accommodative esotropia have included patients with either a high ratio of accommodative convergence to accommodation (AC/A)1-6 or with a partially accommodative esotropia.7,8 Few studies9-12 have reported on status of ocular alignment of exclusively an accommodative esotropia. To our knowledge, only one study has reported all three outcomes,10 and none has reported the development of high AC/A ratio esotropia in patients with previously controlled accommodative esotropia. Minimum followup in these studies ranges from 6 months to 7 years10-12; in one study of adults who had refractive accommodative esotropia in early childhood, patients were reexamined at intervals of 20 or more years.9 In only one study were all
Author affiliations: aSquint Centre, Chandigarh, India; bCornea Centre, Chandigarh, India Submitted July 17, 2013. Revision accepted January 13, 2014. Correspondence: Kanwar Mohan, MS, Squint Centre, SCO : 833-834 (2nd floor), Sector 22-A, Chandigarh – 160022, India (email: [email protected]). Copyright Ó 2014 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2014.01.018
Journal of AAPOS
pretreatment, treatment, and post-treatment examinations performed by the same investigator.9 The purpose of the present study was to report ocular alignment outcomes in patients with refractive accommodative esotropia only who were initially examined, treated, and followed by the same investigator, with a minimum follow-up of 10 years.
Subjects and Methods This study was approved by the Squint Centre Institutional Review Board and complied with the tenets of the Declaration of Helsinki. The medical records of consecutive patients diagnosed with refractive accommodative esotropia at the Squint Centre, Chandigarh, between January 1990 and March 2003 were retrospectively reviewed. Refractive accommodative esotropia was diagnosed if esotropia was eliminated or decreased to within 10D at both near and distance with full cycloplegic hyperopic correction on the first follow-up at least 1 month after the prescription of spectacles. We prescribed full cycloplegic hyperopic correction initially to all patients. Full hyperopic correction was continued if there was orthophoria/esotropia #10D and good visual acuity at the first follow-up. If a patient did not tolerate full correction and had a more than one Snellen line decrease in visual acuity, hyperopic correction was reduced by 0.50–1.0 D to improve visual acuity without affecting alignment status. If reduction of hyperopic correction improved the visual acuity but adversely affected the alignment, atropine instillation once a day for 1 week was prescribed to relax accommodation, and the patient was encouraged to wear full correction. At the 6 month follow-up and annually thereafter, if the patient had no visual
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complaints, good visual acuity, and orthophoria or esotropia of #10D for 2-3 consecutive years, spectacles were undercorrected by 0.50 D to 1.0 D, respectively, depending upon whether cyclopentolate or atropine was used for cycloplegic refraction. If exotropia was observed at any follow-up examination, hyperopic correction was reduced to control exotropia. Full astigmatic refractive correction was prescribed throughout the follow-up. This strategy was uniform for all patients. All patients were followed for at least 10 years. All baseline examinations, treatment, and follow-up examinations were performed by one investigator (KM). Patients who were older than 12 years at presentation, had accommodative esotropia with high AC/A ratio or partially accommodative esotropia, previous extraocular muscle surgery, restricted ocular movements, developmental delay, or neurological disorder were excluded. Patients with coexisting vertical deviation and oblique dysfunctions were not excluded. The following data were collected: age at presentation, age at prescription of full cycloplegic hyperopic correction, bestcorrected visual acuity, measurement of deviation at near and at distance with glasses, and cycloplegic refraction. Ocular alignment was assessed using the prism and alternate cover test in older children and the modified Krimsky test in younger children. Best-corrected visual acuity was measured using the Snellen chart in older children and by binocular fixation pattern in younger patients. Amblyopia was defined as a difference of 2 or more Snellen lines between the best-corrected visual acuity of the two eyes. Lack of alternate fixation in the cover–uncover test was considered diagnostic of amblyopia in younger patients. Cycloplegic refraction was performed after instillation of atropine 1% twice a day for 3 days in children #10 years of age and after 3 instillations of cyclopentolate 1% in those .10 years. Refraction was performed using hand held lenses in uncooperative children and autorefractor (Huvitz, MR-3100 P, Korea) in cooperative children. We repeated cycloplegic refraction on subsequent follow-ups at interval of 6 months in younger patients and 1 year in older patients, as suggested by Dale.13 The spherical equivalent refractive error was calculated as sum of the sphere and one half of the cylinder power. The mean spherical equivalent of the less hyperopic eye or the eye preferred for fixation if both eyes had the same hypermetropia was used for statistical analysis. Anisometropia was defined as a difference of 1.5 D or more in the spherical equivalent refractive error between eyes. Decompensation was defined as an increase of a previously controlled esotropia to .10D both at distance and at near. Any amount of exotropia at near and/or at distance with spectacles was diagnosed consecutive exotropia. High AC/A ratio esotropia was diagnosed if esotropia at near fixation was at least 10D greater than that at distance fixation with full hyperopic correction in place and the AC/A ratio was more than 5:1 by the lens gradient method.14 Statistical analysis was performed using the t test, the Z test for proportions, and the c2 test. Cumulative probability of orthophoria or esotropia of #10D at various follow-ups was determined by Kaplan-Meier survival analysis. A P value of \0.05 was considered statistically significant.
Volume 18 Number 3 / June 2014
Results A total of 107 patients (57 males [53%]) met inclusion criteria. The mean age plus or minus standard deviation at presentation was 4.81 2.64 years (range, 8 months12 years). The mean time interval between presentation and prescription of full cycloplegic hyperopic correction was 0.35 1.13 years (range, 0-7 years). Of the 107 patients, 35 (32.7%) had amblyopia (strabismic, 28 [26.2%]; anisometropic, 7 [6.5%]) at the time of presentation. Two patients each had inferior oblique overaction and dissociated vertical deviation. The mean follow-up period was 12.02 2.25 years (range, 10-21 years). Patients were followed for at least 10 years (107 patients), 15 years (80 patients), 20 years (9 patients), and .20 years (2 patients). At the first examination performed 10 years (mean, 10.2 years) after prescription of glasses, 85 of 107 patients (79%) had orthophoria or esotropia #10D at both near and distance fixation, 14 (13%) had consecutive exotropia, 5 (5%) had decompensation, and 3 (3%) had a high AC/A ratio esotropia. Kaplan-Meier survival analysis demonstrated probabilities of orthophoria/esotropia #10D of 89% at 5 years, 80% at 10 years, and 71% at 15 years (Figure 1). The incidence of various ocular alignment outcomes at different follow-up intervals is shown in Figure 2. Overall, 80 patients (75%) had orthophoria or esotropia #10D at both near and distance at their mean follow-up of 11.62 1.71 years (range, 10-19 years), and 16 (15%) developed consecutive exotropia at a mean 6.70 2.59 years (range, 2.25-10.75 years), 8 (8%) had decompensation of a previously controlled esotropia at a mean 5.97 4.70 years (range, 0.75-12.00 years), and 3 (3%) developed a high AC/A ratio esotropia at a mean 2.56 2.71 years (range, 0.75-5.67 years) after prescription of full hyperopic correction. A modal distribution of the clinical features based on ocular alignment status at the first examination performed 10 years after prescription of glasses is presented in Table 1. There was no statistically significant difference in the mean time interval between presentation and prescription of full hyperopic correction, mean cycloplegic refraction, and presence of amblyopia between patients who developed consecutive exotropia and those who had orthophoria or esotropia #10D (P 5 0.86, P 5 0.45, and P 5 0.15, respectively). The patients with consecutive exotropia had a mean cycloplegic refractive error of 15.55 1.80 D (range, 12.50 to 18.50 D) at the time of prescription of full hyperopic correction and 15.28 1.69 D (range, 10.87 to 17.62 D) at the time of detection of consecutive exotropia, and this difference was not statistically significant (P 5 0.67). Of the 68 patients with \6.0 D hypermetropia, 7 (10.3%) developed consecutive exotropia, compared to 9 (23.1%) of the 39 patients with $6.0 D hypermetropia; this difference was not statistically significant (P 5 0.07). Consecutive exotropia was treated by reductions in hyperopic correction in 12
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There was no statistically significant difference in the mean time interval between presentation and prescription of full hyperopic correction, mean cycloplegic refraction, and presence of amblyopia between patients who developed a high AC/A ratio esotropia and those who had orthophoria or esotropia of #10D (P 5 0.58, P 5 0.43 and P 5 0.92, respectively). The mean cycloplegic refraction was 14.25 2.84 D (range, 12.25 to 17.50 D) at the time of prescription of full hyperopic correction and 14.17 2.70 D (range, 12.25 to 17.25 D) at the time of detection of high AC/A esotropia; this difference was not statistically significant (P 5 0.97).
Discussion
FIG 1. Cumulative probability of orthophoria or esotropia of #10D at various durations of follow-up.
FIG 2. The incidence of various ocular alignment outcomes at different follow-up intervals. The number of patients in each category appears above the bar.
of the 16 patients (75%), initial reductions followed by discontinuation of spectacles in 3 (19%), and strabismus surgery in 1 (6.2%) patients. There was no statistically significant difference in the mean time interval between presentation and prescription of full hyperopic correction, mean cycloplegic refraction, and presence of amblyopia between patients who had decompensation and those who had orthophoria or esotropia of #10D (P 5 0.48, P 5 0.70 and P 5 0.17, respectively). The patients with decompensation had a mean cycloplegic refractive error of 14.70 1.60 D (range, 12.50 to 17.00 D) at the time of prescription of full hyperopic correction and 14.72 1.62 D (range, 11.87 to 17.12 D) at the time of decompensation, and this difference was not statistically significant (P 5 0.99). One of our 2 patients who had inferior oblique overaction developed decompensation. Three patients exhibited a 19D-20D increase in esotropia on near fixation compared to that on distance fixation and had a high AC/A ratio (mean, 6.5:1; range, 6.3:1 to 6.6:1).
Journal of AAPOS
A comparison of various studies on refractive accommodative esotropia is difficult because of different definitions of refractive accommodative esotropia and different minimum durations of follow-up in these studies.2,4,10-12 Refractive accommodative esotropia was diagnosed if the deviation was either eliminated or reduced to within 10D at both near and distance fixation with full cycloplegic hyperopic correction.3 Long follow-up is necessary to evaluate the course of refractive accommodative esotropia after full hyperopic correction. We included patients with a minimum follow-up of 10 years. Watanabe-Numata and colleagues10 examined 49 children who had fully refractive accommodative esotropia at the age of 3 or 4 years and observed that 57% of these children had orthophoria or esotropia of #5D at the age of 10 or 11 years. Reddy and colleagues8 found \8D esotropia in 66% of their patients at a mean follow-up of 3 years, whereas von Noorden and Avilla12 reported orthophoria or small asymptomatic esophoria in 97% of the patients at an average follow-up of 7 years. We observed orthophoria or esotropia #10D in 75% of our patients throughout their mean follow-up of 11.6 years. Consecutive exotropia develops spontaneously in 5% to 15% of patients with refractive accommodative esotropia after a few weeks to an average 5.5 years of full hyperopic correction.9-11 This occurred in 15% of our patients, at a mean of 6.7 years after prescription of full hyperopic correction. Some investigators9,10 have found that amblyopia is a significant risk factor for the development of consecutive exotropia in patients with refractive accommodative esotropia. However, we did not find it to be a risk factor, as also observed by Moore.15 WatanabeNumata and colleagues10 did not find age at the start of hyperopic correction to be a risk factor, in agreement with the present study. Swan9 found that a reduction of hyperopic correction to stimulate accommodative convergence and control exotropia did not help and all patients who required surgery, whereas Watanabe-Numata and colleagues10 reported that 67% of their patients underwent extraocular muscle surgery. In contrast, Beneish and colleagues16 observed that 50% to 60% reduction in hyperopic correction resulted in a satisfactory realignment of
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Table 1. Modal distribution of the clinical features based on ocular alignment status at the first examination performed 10 years after prescription of spectacles Alignment status Clinical features
Orthophoria or esotropia #10D (n 5 85)
Consecutive exotropia (n 5 14)
0.37 1.16 0.00 3.94 16.49
0.43 1.24 0.00 3.20 10.56
5.14 1.91 5.25 0.11 0.81 26 (30.6)
5.55 1.67 4.00 0.33 0.16 7 (50.0)
Time from presentation to full hyperopic correction, years Mean SD Mode Skewness Kurtosis Initial cycloplegic refraction,a D Mean SD Mode Skewness Kurtosis Amblyopia, no. (%)
Decompensation (n 5 5)
0.00 0.00 0.00 0.00 5.47 1.42 4.00 0.19 2.90 3 (60.0)
High AC/A ratio esotropia (n 5 3)
0.00 0.00 0.00 0.00 4.25 2.84 2.25 1.60 — 1 (33.3)
D, diopters; SD, standard deviation. Spherical equivalent hypermetropia.
a
the eyes. Berk and colleagues11 also found that a reduction in hyperopic correction (with subsequent discontinuation of glasses in a few patients) was successful in 62% of their patients and strabismus surgery was required in only 12.5% of cases. In the present study, a large majority (94%) of the patients had control of exotropia with reduction of hyperopic correction; strabismus surgery was performed in only 6% of cases. Decompensation occurs in 2% to 12% of the patients with a previously controlled accommodative esotropia in general1-5,7 and in 13.5% to 33.0% of the patients with an exclusively refractive accommodative esotropia.4,10,12 We observed decompensation in 7.5% of our patients. The mean time at which decompensation occurs has varied from 3.8 years to 5 years.1,3,12 In our patients, decompensation was seen at a mean approximately 6 years after prescription of full hyperopic correction. The earliest time at which decompensation has been reported to occur has been 1 year after the diagnosis of refractive accommodative esotropia.3,4 By contrast, we noted decompensation as early as 9 months after full hyperopic correction. Some investigators found abnormal distance– near relationship,2 a high AC/A ratio,5 a moderate hypermetropia (2.75–4.0 D),1 oblique muscle dysfunction,2,5 amblyopia,5 a long delay between onset of esotropia and glasses prescription,1 failure to fully correct hypermetropia,2 and lack of compliance in glasses wear to be risk factors for decompensation; others did not find delay in treatment,5 severity of AC/A ratio,1 and refractive changes3 to be predictors of decompensation. The present study did not find mean time interval between presentation and prescription of full hyperopic correction, mean initial hypermetropia, and amblyopia to be risk factors for decompensation. Several investigators have reported that decompensation occurs despite hypermetropia remaining static,1,3 an observation borne out by our results. To our knowledge, the development of a high AC/A ratio esotropia in a previously well controlled refractive
accommodative esotropia has not been previously reported. We observed such a development in 3 of our patients at a mean follow-up of 2.5 years after prescription of full hyperopic correction. If a patient with a previously controlled refractive accommodative esotropia exhibits an increase in near esotropia of $10D while hypermetropia is static, a high AC/A ratio esotropia should be considered and the AC/A ratio should be measured using the lens gradient method to differentiate it from nonaccommodative convergence excess. Inferior oblique overaction is seen in 15% to 17% of patients with accommodative esotropia.6,17 However, von Noorden and Avilla12 reported that oblique dysfunction did not occur in refractive accommodative esotropia. Some investigators2,5 have found that decompensation was more common in patients who had inferior oblique overaction. Inferior oblique overaction was observed in only 2 of our patients; thus we cannot comment on the role inferior oblique overaction may play in decompensation. The measurement of a patient’s deviation may vary according to clinician experience and expertise, and inclusion of patients managed by different investigators can result in nonstandardized data. In that regard, the data in the present study is uniform because examinations were performed by the same investigator. Nevertheless, this study does have several limitations. First, the investigator was not masked to the findings of previous examinations; therefore, some element of bias in measurement of deviation cannot be ruled out. Second, AC/A ratio was not measured routinely. Hence, the role of AC/A ratio in decompensation cannot be evalutated. Third, we performed initial cycloplegic refraction using handheld lenses in uncooperative children and autorefractor during followups when these children were old enough and cooperative. Hence the refraction measurements may not be comparable. Fourth, sensory data was not reported. Finally, the follow-up period was not uniform for all patients.
Journal of AAPOS
Volume 18 Number 3 / June 2014
Literature Search A literature search was performed on PubMed using the following terms: accommodative esotropia, refractive accommodative esotropia, and high AC/A ratio esotropia.
Acknowledgments The authors thank Dr. Suresh Sharma, Department of Statistics, Punjab University, Chandigarh, for his statistical analysis of the study data. References 1. Dickey CF, Scott WE. Deterioration of accommodative esotropia: frequency, characteristics and predictive factors. J Pediatr Ophthalmol Strabismus 1988;25:172-5. 2. Black BC. The influence of refractive error management on the natural history and treatment outcome of accommodative esotropia. Trans Am Ophthalmol Soc 2006;104:303-21. 3. Raab EL. Monitoring of controlled accommodative esotropia. Trans Am Ophthalmol Soc 2001;99:225-31. 4. Mohney BG, Lilley CC, Green-Simms AE, Diehl NN. The long-term follow-up of accommodative esotropia in a populationbased cohort of children. Ophthalmology 2011;118:581-5. 5. Ludwig IH, Imberman SP, Thompson HW, Parks MM. Long-term study of accommodative esotropia. J AAPOS 2005;9:522-6. 6. Rutstein RP, Marsh-Tootle W. Clinical course of accommodative esotropia. Optom Vis Sci 1998;75:97-102.
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7. Mulvihill A, MacCann A, Flitcroft I, O’ Keefe M. Outcome in refractive accommodative esotropia. Br J Ophthalmol 2000;84:746-9. 8. Reddy AK, Freeman CH, Paysse EA, Coats DK. A data-driven approach to the management of accommodative esotropia. Am J Ophthalmol 2009;148:466-70. 9. Swan KC. Accommodative esotropia long range follow-up. Ophthalmology 1983;90:1141-5. 10. Watanabe-Numata K, Hayasaka S, Watanabe K, Hayasaka Y, Kadoi C. Changes in deviation following correction of hyperopia in children with fully accommodative esotropia. Ophthalmologica 2000;214:309-11. 11. Berk AT, Kocak N, Ellidokuz H. Treatment outcomes in refractive accommodative esotropia. J AAPOS 2004;384-8. 12. von Noorden GK, Avilla CW. Refractive accommodative esotropia : a surgical problem. Int Ophthalmol 1992;16:45-8. 13. Dale RT. Fundamentals of Ocular Motility and Strabismus. New York: Grune and Stratton, Inc; 1982:194. 14. Arnoldi KA, Tychsen L. Surgery for esotropia with a high accommodative convergence/accommodation ratio: effects on accommodative vergence and binocularity. Ophthalmic Surg Lasers 1996; 27:342-8. 15. Moore S. The natural history of esotropia. Am Orthopt J 1971;21: 80-83. 16. Beneish R, Williams F, Polomeno RC, Little JM. Consecutive exotropia after correction of hyperopia. Can J Ophthalmol 1981; 16:16-18. 17. Raab EL. Etiological factors in accommodative esodeviation. Trans Am Ophthalmol Soc 1982;80:657-94.
