Clinical Features, Rate of Systemic Abnormalities and Surgical Outcomes of Infantile Exotropia in a Regional Hospital of Hong Kong 1994 to 2010

Dr Wai-Ho Chan, Dr Joyce Lam, Dr Chi Kin Ho

Tuen Mun Hospital

Purpose: To evaluate the clinical features, rate of systemic abnormalities and the surgical outcomes of infantile exotropia (XT) in a Regional Hospital of Hong Kong.

Methods: Retrospective, observational case series. Medical records of all patients diagnosed with XT before 12 months of age between 1994 and 2010 were reviewed. Children with significant ocular defects that would reduce vision were excluded.

Results: Twenty-four XT patients were identified with mean age of onset 4.3 months (range, 0 to 12 months). Nineteen patients (79%) had constant XT and 5 patients (21%) had intermittent XT. Two patients (8%) had nystagmus and two patients (8%) had V-pattern exotropia secondary to inferior oblique overaction. Ten patients had MRI brain done with three of them had abnormal findings. Thirteen (54%) out of 24 patients had congenital or developmental diseases requiring follow up in other specialties.

Sixteen patients had strabismus surgery done with minimal postoperative follow up of three years and the preoperative angle of deviation was 35 – 70 PD. Seven (44%) out of 16 need reoperations for horizontal deviation. Eleven (69%) of them had final horizontal deviations of less than 10 PD.

Conclusions: A high percentage of our patients had abnormal MRI brain findings and associated congenital or developmental diseases. Clinicians should consider that children presenting with infantile exotropia appear to be at risk for systemic diseases. Like patients with infantile esotropia, those with exotropia can be expected to have good surgical outcome but reoperation rate (44%) was high.