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Published on: April 3, 2016
Long-term outcome of uncomplicated infantile exotropia
D G Hunter1, J B Kelly, A N Buffenn
1Krieger Children's Eye Center at the Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9028, USA. dhunter@jhmi.edu
Insights
Infantile exotropia (XT) can present as intermittent or constant, with similar outcomes. Surgery is effective for alignment, and many infants develop some stereopsis.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Strabismus
Background:
- Congenital exotropia (XT) is often defined restrictively, typically for infants presenting with a large, constant angle within the first year of life.
- The rationale behind this restrictive definition lacks published support.
- This study aims to evaluate the current classification system for XT and characterize differences between infants with constant versus intermittent XT at presentation.
Purpose of the Study:
- To evaluate the existing classification system for congenital exotropia (XT).
- To characterize differences between infants presenting with constant versus intermittent XT.
- To assess the clinical features and outcomes of infantile XT based on presentation type.
Main Methods:
- Retrospective review of medical records for patients diagnosed with XT before 12 months of age (1980-1994).
- Exclusion criteria included prior eye muscle surgery, early resolution of XT, and coexisting systemic or ocular diseases.
- Patients were categorized into intermittent XT and constant XT groups for comparison of clinical characteristics and outcomes.
Main Results:
- 1.1% of infants examined for any cause presented with XT (23 patients).
- Of 13 patients with >1 year follow-up, 46% had constant XT; initial angle was larger in constant XT (P=.02).
- 92% required surgery, 27% needed reoperation, and 82% achieved <10 PD final horizontal deviation; A/V-patterns, dissociated vertical deviation, and binocularity were similar between groups.
Conclusions:
- Infantile XT can present as intermittent in half of cases, with comparable clinical outcomes to constant XT.
- Surgical intervention is generally successful in achieving ocular alignment.
- While many patients develop measurable stereopsis, bifixation is not achieved.
Purpose:
The term congenital exotropia (XT) is typically reserved for patients presenting in the first year with a large, constant angle, however, no published study provides a rationale for this restrictive definition. In this study, the present classification system for XT was evaluated and differences between infants with constant versus intermittent XT at presentation were characterized.
Methods:
Medical records of all patients diagnosed with XT before 12 months of age between 1980 and 1994 were identified by computer search. Exclusion criteria included previous eye muscle surgery, resolution of the XT by 3 months of age, and concomitant systemic or ocular disease. Patients were separated into intermittent XT and constant XT groups. The clinical characteristics and outcomes of these two groups were compared.
Results:
Of 2018 patients examined on our service during the first year of life for all causes, 23 (1.1 %) met the inclusion criteria. Follow-up data of more than 1 year was available for 13 patients, and of these, 46% had constant XT. The 2 groups had similar clinical features at presentation except for a larger initial angle in the constant XT group (P =.02). Average follow-up was 58 months (range: 13-158 months). Twelve patients (92%) required surgery. The reoperation rate was 27%, and 82% had final horizontal deviations of less than 10 PD. The incidence of A/V-patterns (38%), dissociated vertical deviation (46%), and binocularity (70%) was similar between groups.
Conclusion:
Half of infantile XT patients may present with intermittent XT, with similar clinical outcomes regardless of presentation. Surgical intervention resulted in successful alignment in most cases. More than half the patients developed measurable stereopsis, but none achieved bifixation.
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