Hirschberg & Krimsky Test — Strabismus Angle Estimation
Bedside estimation of ocular deviation when prism cover test is impractical (uncooperative child, dense amblyopia). Hirschberg: corneal light reflex displacement from pupil centre; each 1 mm ≈ 7° (≈15 prism dioptres / 15Δ). Krimsky modifies by adding prisms over fixing eye until reflex is centred.
Score interpretation
→ No manifest deviation. Assess for latent (phoria) with cover-uncover. Consider refractive error, accommodation, and stereopsis (TNO, Lang, Frisby).
→ Refractive correction (cycloplegic refraction — atropine for hyperopia in accommodative ET). Patching for amblyopia per PEDIG protocols. Orthoptic exercises if convergence insufficiency.
→ Refractive correction first. If residual deviation persists ≥6 months, consider strabismus surgery (recess-resect) or botulinum toxin in selected cases.
→ Cycloplegic refraction. Imaging (MRI) if onset >3 months or atypical features (variability, ptosis, proptosis) to exclude cranial nerve palsy or orbital lesion. Strabismus surgery (often bilateral procedures); consider augmented adjustable sutures in adults.
Interpretation bands for the Hirschberg / Krimsky. Apply clinical judgement and local guidance.
References
Related
Curated clinical cross-links plus same-class fallbacks.
- Tetracosactide · Synthetic ACTH (short Synacthen test)
- Melatonin · Melatonin Receptor Agonist
- Urea (13C) · 13C-urea breath test
- Phytomenadione (Vitamin K1) · Vitamin K (clotting factor cofactor)
- Phytomenadione (Vitamin K1) · Vitamin K (Coagulation Factor Synthesis)
- Ibuprofen (Orthopaedic Musculoskeletal Pain) · NSAID — Non-selective COX Inhibitor
- Acute Red Eye / Vision Loss Screen · RCOphth 2020; NICE CKS
- Idiopathic Intracranial Hypertension · ABN; consensus 2018
- Acute Red Eye Assessment · RCOphth / AAO
- Acute Angle Closure Glaucoma · RCOphth / EGS Guidelines
- Retinal Detachment · RCOphth Guidelines / EURETINA
- Diabetic Retinopathy — Screening and Management · NICE NG28 2016 / NHS DES Programme
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.