A 58-year-old man presents to the ophthalmology clinic for routine eye examination. He is asymptomatic and has no ocular complaints. On examination, intraocular pressure (IOP) is 24 mmHg in both eyes (normal <21 mmHg). Gonioscopy reveals open angles. Optic disc examination shows a cup-to-disc ratio (CDR) of 0.7 with inferior notching and a thin neuroretinal rim. Visual field testing shows a superior arcuate defect in the left eye. The patient has no family history of glaucoma. What is the most appropriate next step in management?

Explanation

## Diagnosis and Clinical Context This patient presents with clinical features highly suggestive of **Primary Open-Angle Glaucoma (POAG)**: - Elevated IOP (24 mmHg) - Open angles on gonioscopy - Optic disc changes (CDR 0.7, inferior notching, thin rim) - Visual field defect (superior arcuate) ## Why Confirmation Before Treatment Is Essential **Key Point:** Although the clinical picture is suggestive of POAG, the diagnosis requires documentation of progressive glaucomatous optic neuropathy and/or visual field loss. A single VF defect may represent artifact or other non-glaucomatous pathology. **High-Yield:** POAG diagnosis requires: 1. Elevated IOP (or normal-tension variant) 2. Open angles on gonioscopy 3. Glaucomatous optic neuropathy (structural changes) 4. **Reproducible visual field defect** (confirmed on repeat testing) ## Recommended Approach **Clinical Pearl:** Before initiating irreversible pharmacologic therapy, obtain baseline OCT imaging of the optic nerve head and retinal nerve fiber layer (RNFL) to quantify structural damage. Repeat visual field testing within 4–8 weeks confirms the defect is reproducible and not artifact. **Tip:** Confirming the diagnosis protects against over-treatment and ensures informed consent for lifelong therapy. ## Management Algorithm ```mermaid flowchart TD A[Suspected POAG: elevated IOP + optic disc changes + VF defect]:::outcome A --> B[Baseline OCT RNFL and optic disc]:::action B --> C[Repeat VF in 4-8 weeks]:::action C --> D{VF defect reproduced?}:::decision D -->|Yes| E[Confirmed POAG diagnosis]:::outcome D -->|No| F[Consider other diagnoses]:::outcome E --> G[Initiate topical therapy]:::action F --> H[Annual monitoring]:::action ``` **Key Point:** Once POAG is confirmed, first-line therapy is typically a prostaglandin analogue (latanoprost, travoprost, bimatoprost) or a beta-blocker, depending on patient factors and contraindications.