Glaucoma: causes, types, diagnosis and treatment

Signs and symptoms

Symptoms depend on the type and stage. Chronic forms typically erode peripheral (side) vision first and progress slowly, so patients may not notice changes until advanced loss occurs. Acute or angle-closure glaucoma presents suddenly with severe eye pain, headache, blurred vision, colored halos around lights, nausea, and a red eye — a medical emergency that requires immediate care.

Causes and pathophysiology

Normal eye function depends on a balance between production and drainage of aqueous fluid. When drainage is reduced or fluid production increases, intraocular pressure can rise and compress the optic nerve fibers at the optic disc. This leads to characteristic optic nerve cupping and loss of retinal ganglion cells. Other mechanisms include vascular insufficiency, genetic susceptibilities, inflammation, trauma, or secondary causes such as steroid use.

Diagnosis

Comprehensive eye exams combine several tests to evaluate structure and function:

• Tonometry to measure eye pressure.
• Ophthalmoscopy to inspect the optic nerve head and detect cupping (optic nerve evaluation).
• Visual field testing to map peripheral vision loss.
• Optical coherence tomography (OCT) to image nerve fiber layers.

Treatment and management

There is no cure that restores lost optic nerve tissue; treatment aims to preserve remaining vision by lowering eye pressure and addressing contributing factors. Options include:

• Topical medications (prostaglandin analogs, beta blockers, carbonic anhydrase inhibitors, alpha agonists) or systemic drugs to reduce fluid production or increase outflow.
• Laser procedures such as trabeculoplasty for open-angle glaucoma or iridotomy for angle closure.
• Surgical procedures (trabeculectomy, tube shunts) and newer minimally invasive glaucoma surgeries (MIGS) for resistant cases.
• Lifelong monitoring and adherence to therapy to slow progression.

Types, risk factors and public health

Major categories include primary open-angle glaucoma (the most common, slow and often asymptomatic), primary angle-closure glaucoma (can be acute), normal-tension glaucoma (optic nerve damage at normal pressures), secondary glaucoma (following injury, inflammation, or medication use), and congenital glaucoma in infants. Risk is increased by older age, family history, certain ethnic backgrounds, myopia, diabetes, and prior steroid use. Globally, glaucoma is a leading cause of irreversible blindness; early detection through screening of at-risk groups and prompt treatment reduce the burden of vision loss.

For introductory resources and clinical guidance, see general overviews of glaucoma and professional recommendations on screening and management.