Refractive Error & Myopia Severity Classification
International Myopia Institute classification (IMI 2019): myopia is a spherical equivalent (SE) of −0.50 D or less, high myopia −6.00 D or less, using cycloplegic refraction in children. Pathologic myopia is defined by structural changes, not by refraction. Higher myopia confers greater lifetime risk of myopic maculopathy, retinal detachment, glaucoma, and cataract.
Score interpretation
SE more positive than −0.50 D. In children, −0.50 to +0.75 D with risk factors is 'pre-myopia' (IMI 2019).
→ Children: cycloplegic refraction; treat amblyopia and accommodative esotropia with full correction if significantly hyperopic; encourage outdoor time if pre-myopic. Adults: spectacles/contact lenses if symptomatic; assess for asthenopia and angle closure risk in hyperopia.
SE −0.50 D or less, but more positive than −6.00 D (IMI 2019).
→ Spectacles/contacts. In children: discuss myopia control (low-dose atropine eye drops — Children: use a children's formulary. dual-focus contact lenses, MiSight, orthokeratology) per IMI 2021; active myopia control if progressing. Outdoor time ≥2 h/day. Discuss lifetime retinal detachment risk.
SE −6.00 D or less (IMI 2019).
→ Posterior segment surveillance (OCT macula + dilated peripheral retina) every 1–2 years. Counsel on symptoms of detachment (flashes/floaters/curtain). Look for posterior staphyloma / myopic maculopathy (pathologic myopia); treat myopic CNV (anti-VEGF — NICE TA298 ranibizumab). Refractive surgery options if stable; ICL preferred over LASIK above ~−10 D. Active myopia control in children.
Interpretation bands for the Myopia Severity. Apply clinical judgement and local guidance.
References
Related
Curated clinical cross-links plus same-class fallbacks.
- Hydroxocobalamin (High-Dose — Cyanide Antidote) · Cyanide Antidote (Vitamin B12 Precursor at High Dose)
- Thiamine (IV/IM — Pabrinex) · Vitamin B1 (Thiamine) — deficiency treatment / Wernicke's encephalopathy prevention
- Calcium chloride · IV calcium salt (high elemental calcium)
- Thiamine (Vitamin B1) · Vitamin B1 Supplement
- Vitamin B substances with ascorbic acid · High-potency parenteral B + C vitamins
- Atropine Eye Drops 1% / 0.01% · Antimuscarinic — Cycloplegic / Myopia Control
- 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.