A 3-year-old child is brought to the outpatient clinic by his mother with a complaint of inward deviation of the right eye since birth. On examination, the child has a well-maintained fixation with each eye separately, normal pupillary responses, and clear media. The angle of deviation is 35 prism diopters on the cover test. There is no history of diplopia. What is the most appropriate next step in management?

Explanation

## Clinical Context This is a case of **congenital esotropia** (inward deviation of the eye) presenting in a young child with a significant deviation (35 PD) and good visual function in both eyes. ## Management Approach for Congenital/Infantile Esotropia **Key Point:** The first step in managing any strabismus in a child is **cycloplegic refraction and optical correction**, even in cases of apparent congenital esotropia. Many cases have an underlying refractive error (hyperopia) that contributes to the deviation. **High-Yield:** The standard management sequence for infantile esotropia is: 1. Cycloplegic refraction (using cyclopentolate 1% or tropicamide 1%) 2. Prescription of appropriate glasses 3. Observation for 3–6 months to assess response 4. If deviation persists after optical correction, surgical intervention is considered ## Why This Approach? - **Cycloplegic refraction** eliminates accommodation-related deviation and reveals true refractive error - **Hyperopia** (common in this age group) increases accommodative convergence, worsening esotropia - **Glasses prescription** can reduce or eliminate the deviation in 30–40% of cases - **Observation period** allows time for spontaneous improvement and assessment of glasses efficacy - **Surgery is deferred** until optical correction has been optimized and given adequate trial **Clinical Pearl:** Even in cases of large-angle esotropia, glasses should be prescribed first. If the deviation is purely refractive (accommodative esotropia), glasses alone will correct it. If residual deviation persists after 3–6 months of glasses wear, surgery is then indicated. **Mnemonic: REFR-ACT** — **R**efraction (cycloplegic), **E**xamine for refractive error, **F**ull optical correction, **R**eview after 3–6 months, then **A**ssess need for **C**orrective surgery, **T**hen refer if needed. ## Why Not Immediate Surgery? Surgery is NOT the first step because: - Optical correction may resolve or reduce the deviation - Refractive error must be ruled out first - Premature surgery risks overcorrection or undercorrection ## Why Not Patching? Patching (occlusion therapy) is used for **amblyopia prevention** in cases with visual deprivation, not as primary treatment for the strabismus itself. The child has good fixation in both eyes, so amblyopia risk is low at this stage.