Esotropia and Exotropia: Types, Tests and Surgery
Last updated: November 2026
Most childhood squints are horizontal: an inward turn (esotropia) or an outward turn (exotropia). Classifying them correctly decides whether the answer is glasses, patching, prisms or surgery.
Esotropia
| Type | Features | Management |
|---|---|---|
| Infantile (congenital) | Onset before 6 months; large stable angle (often over 30 Δ); cross-fixation; DVD, IO overaction, latent nystagmus | Early surgery (bilateral medial rectus recession), usually before age 2 |
| Refractive accommodative | Onset 2–3 years; hypermetropia (+2 to +6 D); normal AC/A | Full cycloplegic correction; usually no surgery |
| High AC/A (non-refractive) accommodative | Larger deviation at near than distance | Bifocals or executive lenses; surgery in some |
| Partially accommodative | Residual deviation with full glasses | Glasses plus surgery for the residual angle |
| Acquired non-accommodative and sixth nerve palsy | Sudden onset, larger at distance, abduction deficit | Investigate (neuro-imaging if no obvious cause) |
| Sensory | Poor vision in one eye | Treat the cause; exclude retinoblastoma in children |
Exotropia
| Type | Features | Management |
|---|---|---|
| Intermittent exotropia (X(T)) | The commonest; eye drifts out when tired or daydreaming, closes one eye in bright sunlight | Observe if well controlled (Newcastle control score); overminus lenses, part-time occlusion; surgery if control deteriorates |
| Basic vs divergence excess vs convergence insufficiency | Compare distance and near deviation (after a patch test for near) | Lateral rectus recession for divergence excess; recess-resect for basic; convergence exercises for convergence insufficiency |
| Constant and sensory exotropia | Poor vision in one eye, or decompensated X(T) | Treat the cause; surgery |
| Consecutive exotropia | After esotropia surgery | Further surgery if needed |
Essential tests
- Cover tests and prism cover test at near and distance (and far distance for X(T)).
- Cycloplegic refraction and fundus examination in every child.
- AC/A ratio, stereopsis, ocular movements (A and V patterns, oblique overaction).
- Amblyopia assessment and treatment before surgery.
Where residents slip
- Operating on an accommodative esotropia before full cycloplegic glasses.
- Not examining the fundus of a child with a squint.
- Measuring X(T) only at near.
Test yourself: flip cards
Related: Strabismus Measurement and Surgical Dose Tables: Quick Reference, Refraction Calculators: Near Add, AC/A Ratio, Retinoscopy and Prism, Amblyopia: Classification, Severity and PEDIG Treatment Lessons.
Key sources
- Pediatric Eye Disease Investigator Group. A randomized trial comparing bilateral lateral rectus recession vs unilateral recess and resect for basic-type intermittent exotropia. Ophthalmology. 2019
- Haggerty H, et al. The Newcastle Control Score. Br J Ophthalmol. 2004;88:233-235
📘 Want more exam-ready material? See Most Commons in Ophthalmology on Kindle, or browse all my books.
Looking for an eye specialist in Ahmedabad? Learn about our Eye Department or book a consultation with Dr. Dhaval Patel.