IOP normal range (optometry)
Structured for Australian optometry practice.
Clinical decision support only
OptoGuide™ supports professional judgement and does not diagnose or replace clinician responsibility.
Quick answer
- A common reference range is around 10 to 21 mmHg, but interpretation depends on disc appearance, corneal thickness, asymmetry, and symptoms.
- A single pressure reading does not diagnose or exclude glaucoma.
- Large asymmetry, symptomatic pressure rise, or pressure out of context with the nerve should change next steps.
- IOP should be interpreted alongside optic nerve, fields, angles, and risk profile rather than in isolation.
Common causes
- Physiological variation within a normal range.
- Ocular hypertension without confirmed glaucomatous damage.
- Raised IOP secondary to angle closure, steroid response, or inflammation.
- Low IOP after surgery, leak, inflammation, or ciliary body dysfunction.
Red flags (must not miss)
- Painful eye, haloes, nausea, or acute unilateral rise.
- Marked inter-eye asymmetry with suspicious nerve findings.
- Very high IOP with reduced vision or corneal oedema.
- Hypotony with reduced vision or recent surgery.
Use OptoGuide™ to guide this decision during consult.
What to check
- Repeat IOP if the reading is unexpected or borderline.
- Optic nerve appearance, disc asymmetry, and rim status.
- Corneal thickness or corneal factors affecting interpretation where available.
- Anterior chamber angle status and relevant medication history.
- Visual fields and OCT context if glaucoma is a concern.
When to refer
- Urgent referral for acute angle-closure features or symptomatic markedly raised IOP.
- Routine glaucoma referral when pressure is elevated with suspicious nerve or field findings.
- Escalate if there is progressive structural or functional change, even with modest IOP.
Initial management
- Interpret pressure in the context of nerve, field, and angle findings.
- Repeat and confirm unexpected measurements before concluding they are stable.
- Prioritise acute symptom profile over the numerical IOP value alone.
Clinical basis
This guidance reflects standard optometric clinical reasoning based on:
- Australian optometry clinical practice patterns
- Australian medicines regulation and PBS prescribing context
- Common ophthalmology referral standards
- Evidence-based clinical training and practice
Use OptoGuide™ during consult for structured clinical guidance.