Ocular Pharmacology and Therapeutic Prescribing
What this domain tests
This domain tests safe prescribing within the optometric scope, drug selection, adverse effects, contraindications and documentation. Candidates must know when not to prescribe and when referral is safer.
Core rules and concepts
- Prescribing must be within the optometrist’s approved scope and the relevant New Zealand medicines framework; endorsed therapeutic prescribers must follow legal and formulary requirements.
- Topical steroids can mask infection, raise intraocular pressure and worsen herpes simplex keratitis.
- Mydriatics and cycloplegics cause photophobia and temporary blur; caution in angle-closure risk.
- Preservatives such as benzalkonium chloride can cause toxicity in frequent-drop users and in corneal disease.
- Record drug, dose, frequency, duration, indication, advice and follow-up.
Worked example
A patient has a dendritic corneal ulcer with staining. Reasoning: this suggests herpes simplex keratitis. Topical steroid alone is contraindicated because it can promote viral replication and worsen the ulcer. Refer for ophthalmological management and antiviral therapy; do not initiate steroid. Document the dendritic pattern and the referral urgency.
Traps that cost marks
Prescribing steroid for an undiagnosed red eye; missing a history of herpes simplex; failing to check for pregnancy, allergy or current medicines; not recording batch or follow-up; assuming all optometrists have unrestricted prescribing rights.
Key points
- Steroid can mask infection and worsen herpes simplex keratitis.
- Prescribe only within approved scope and legal requirements.
- Dendritic ulcer requires referral and antiviral management.
- Preservatives can cause corneal toxicity.
- Document indication, dose, duration and follow-up.