Elevated Intraocular Pressure as the Central Risk Factor
Placeholder: high IOP is the main modifiable driver of glaucoma damage.
- 10–21: Normal IOP (mmHg reference range)
- 22–30: Common OAG range (mmHg at diagnosis)
- ~3%: Prevalence (placeholder over age 40)
- Late: Symptom onset (often asymptomatic early)
Why pressure matters
Placeholder: sustained elevated pressure stresses the optic nerve head.
Placeholder: early detection prevents irreversible damage.
Progressive Cupping of the Optic Nerve Head
Placeholder: the cup-to-disc ratio grows year over year under pressure.
- <0.4: Normal cup ratio (placeholder healthy disc)
- >0.6: Glaucomatous ratio (placeholder damage marker)
- Variable: Progression rate (placeholder per patient)
- None: Reversibility (placeholder axon loss is permanent)
Cupping mechanism
Placeholder: axon loss thins the neuroretinal rim over time.
Placeholder: rim thinning precedes measurable field loss.
Visual Field Loss from Retinal Ganglion Cell Death
Placeholder: peripheral field loss follows nerve fiber layer thinning.
- Peripheral: First loss area (placeholder arcuate scotoma)
- Perimetry: Detection tool (placeholder standard test)
- Late loss: Central vision (placeholder end-stage)
- 6–12mo: Field test interval (placeholder monitoring)
Field loss pattern
Placeholder: arcuate and nasal step defects appear before central loss.
Placeholder: untreated progression can lead to blindness.
Prostaglandin Analogs — First-Line IOP-Lowering Drops
Placeholder: latanoprost-class drops boost uveoscleral outflow strongly.
- 25–33%: IOP reduction (placeholder typical range)
- Once daily: Dosing (placeholder evening dose)
- ↑ Outflow: Mechanism (placeholder uveoscleral route)
- Iris darkening: Side effect (placeholder cosmetic note)
Mechanism of action
Placeholder: relaxes ciliary muscle to open uveoscleral drainage.
Placeholder: preferred first-line therapy for most patients.
Beta-Blockers — Reducing Aqueous Humor Production
Placeholder: timolol-class drops cut fluid production at the ciliary body.
- 20–25%: IOP reduction (placeholder typical range)
- 1–2x daily: Dosing (placeholder twice daily common)
- ↓ Production: Mechanism (placeholder ciliary epithelium)
- Cardiopulmonary: Caution (placeholder systemic effects)
Mechanism of action
Placeholder: blocks beta receptors to lower aqueous secretion rate.
Placeholder: useful alternative when prostaglandins are contraindicated.