PURPOSE: The purpose of this study is to compare the magnitude and axis of astigmatism induced by a combined inferior oblique (IO) anterior transposition procedure with lateral rectus (LR) recession versus LR recession alone. METHODS: Forty-six patients were retrospectively analyzed. The subjects were divided into two groups: those having concurrent inferior oblique muscle overaction (IOOA) and intermittent exotropia (group 1, 20 patients) and those having only intermittent exotropia as a control (group 2, 26 patients). Group 1 underwent combined anterior transposition of IO with LR recession and group 2 underwent LR recession alone. Induced astigmatism was defined as the difference between preoperative and postoperative astigmatism using double-angle vector analysis. Cylinder power, axis of induced astigmatism, and spherical equivalent were analyzed at 1 week, 1 month, and 3 months after surgery. RESULTS: Larger changes in the axis of induced astigmatism were observed in group 1, with 4.5° incyclotorsion, than in group 2 at 1 week after surgery (axis, 84.5° vs. 91°; p < 0.001). However, there was no statistically significant inter-group difference thereafter. Relaxation and rapid regression in the incyclotorsion of induced astigmatism were observed over-time. Spherical equivalent significantly decreased postoperatively at 1 month in both groups, indicating a myopic shift (p = 0.011 for group 1 and p = 0.019 for group 2) but did not show significant differences at 3 months after surgery (p = 0.107 for group 1 and p = 0.760 for group 2). CONCLUSIONS: Combined IO anterior transposition procedures caused an increased change in the axis of induced astigmatism, including temporary incyclotorsion, during the first week after surgery. However, this significant difference was not maintained thereafter. Thus, combined IO surgery with LR recession does not seem to produce a sustained astigmatic change, which can be a potential risk factor of postoperative amblyopia or diplopia compared with LR recession alone.
Astigmatism/diagnosis/*etiology/physiopathology ; Child ; Exotropia/diagnosis/physiopathology/*surgery ; Eye Movements/*physiology ; Female ; Follow-Up Studies ; Humans ; Male ; Oculomotor Muscles/*surgery ; Ophthalmologic Surgical Procedures/*methods ; Retrospective Studies ; Treatment Outcome ; Vision, Binocular/*physiology

An 11-year-old female presenting diplopia only at distance was found to have comitant esotropia of 20 prism diopters (PD) at distance and normal alignment at nearer proximity. Other ocular movement, including abduction, was normal and a thorough neurologic examination was also normal. The deviation angle of esotropia was increased to 35 PD in 6 months, and a brain magnetic resonance imaging with venogram at that time demonstrated no intracranial lesion. A lumbar puncture showed increased opening pressure but the cerebrospinal fluid composition was normal. The patient was diagnosed as having idiopathic intracranial hypertension and treated with oral acetazolamide. Three months after treatment, the deviation angle decreased to 10 PD. This is a case report of divergence insufficiency in pediatric idiopathic intracranial hypertension, with an increasing deviation angle of esotropia. Although sixth cranial nerve palsy is a common neurologic manifestation in intracranial hypertension, clinicians should be aware of the possibility of divergence insufficiency. Also, ophthalmoparesis may not be apparent and typical at first presentation, as seen in this case, and therefore ophthalmologists should be aware of this fact, while conducting careful and proper evaluation, follow-up, and intervention.
Acetazolamide/administration & dosage ; Administration, Oral ; Child ; Diagnosis, Differential ; Diuretics/administration & dosage ; Esotropia/diagnosis/*etiology/physiopathology ; Exotropia/diagnosis/*etiology/physiopathology ; Eye Movements ; Female ; Follow-Up Studies ; Humans ; Intracranial Pressure ; Magnetic Resonance Imaging ; Pseudotumor Cerebri/*complications/diagnosis/drug therapy ; Spinal Puncture/methods ; Vision, Binocular ; Visual Acuity