An 8-year-old girl has a left esotropia of 20 prism dioptres. The left eye shows markedly restricted abduction, while adduction is full but accompanied by narrowing of the left palpebral fissure and backward retraction of the globe. Adduction saccades are slow. Which is the MOST likely diagnosis?

• A Congenital sixth nerve palsy
• B Medial orbital wall fracture with medial rectus entrapment
• C Duane retraction syndrome, Huber type 1 ✓
• D Möbius syndrome

Explanation

Type 1 Duane retraction syndrome shows deficient abduction with normal or near-normal adduction. Co-contraction of the lateral rectus by aberrant medial rectus innervation produces globe retraction and palpebral fissure narrowing on adduction, a pathognomonic feature absent in abducens palsy, where adduction is unaffected and the fissure does not narrow. Female preponderance and frequent left eye involvement also fit.

Reference: Taylor and Hoyt's Pediatric Ophthalmology and Strabismus, 5th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.