For patients and families

What it is

Glaucoma is a group of eye diseases that damage the optic nerve, usually slowly.¹ ² Side (peripheral) vision tends to go first, so many people do not notice anything until the damage is advanced.² Vision lost to glaucoma does not come back, but treatment can slow or help prevent further loss.¹ ³ ⁴

Types

• Open-angle glaucoma, the most common type in the United States, usually develops slowly and without pain.²
• Angle-closure glaucoma can happen suddenly when fluid cannot drain from the eye.²
• Glaucoma with normal eye pressure (normal-tension glaucoma) also occurs, which is why pressure alone does not rule glaucoma in or out.¹

Who is at higher risk

Risk is higher with older age, a family history of glaucoma, African or Hispanic/Latino ancestry (open-angle glaucoma), East Asian ancestry (angle-closure glaucoma), higher eye pressure, a thinner central cornea, high nearsightedness, and long-term steroid use.¹ ² ⁵

Emergency signs

Sudden eye pain, a red eye, blurred vision, halos around lights, headache, nausea, or vomiting can be acute angle-closure glaucoma. Go to an eye doctor or emergency department right away.²

How it is found and treated

A comprehensive dilated eye exam looks at the optic nerve, measures eye pressure, and may include OCT imaging and a visual field test (see What to expect at an eye exam). Treatment lowers eye pressure with eye drops, laser treatment, or surgery.¹ ⁶ Keeping follow-up visits matters, because glaucoma is monitored over years.

For clinicians

• Diagnosis rests on characteristic optic nerve and RNFL change with corresponding visual field loss; OCT (RNFL and ganglion cell complex) and standard automated perimetry are the core tests for detection and progression.¹
• IOP lowering is the only proven modifiable treatment. OHTS showed that topical treatment delayed or prevented the onset of POAG in ocular hypertension,³ and EMGT showed that IOP reduction slowed progression in early manifest glaucoma.⁴ The LiGHT trial supports selective laser trabeculoplasty as a first-line option.⁶
• Differentiate from non-glaucomatous optic neuropathy. Pallor out of proportion to cupping, a young age, vision or color loss out of proportion to cupping, vertical-meridian-respecting field defects, or progression despite low IOP should prompt consideration of compressive, ischemic (including prior NAION or AAION), hereditary, or toxic causes and neuro-imaging as indicated.¹ ⁷
• Consult the AAO Preferred Practice Pattern for staging, target IOP, and follow-up intervals.¹

References

1. Gedde SJ, et al. Primary Open-Angle Glaucoma Preferred Practice Pattern®. Ophthalmology. 2026;133(4):P1-P103. https://pubmed.ncbi.nlm.nih.gov/41665583/
2. National Eye Institute. Glaucoma. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma · American Academy of Ophthalmology. What Is Glaucoma? https://www.aao.org/eye-health/diseases/what-is-glaucoma
3. Kass MA, et al. The Ocular Hypertension Treatment Study. Arch Ophthalmol. 2002;120(6):701-713. https://pubmed.ncbi.nlm.nih.gov/12049574/
4. Heijl A, et al. Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial. Arch Ophthalmol. 2002;120(10):1268-1279. https://pubmed.ncbi.nlm.nih.gov/12365904/
5. Gordon MO, et al. The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002;120(6):714-720. https://pubmed.ncbi.nlm.nih.gov/12049575/
6. Gazzard G, et al. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT). Lancet. 2019;393(10180):1505-1516.
7. Biousse V, Newman NJ. Diagnosis and clinical features of common optic neuropathies. Lancet Neurol. 2016;15(13):1355-1367.

How to reach us

Hazleton Eye Specialists: phone 570-453-2020, fax 570-453-1020. Addresses for all five offices (Hazleton, Stroudsburg, Nanticoke, Pottsville, and Bangor) are on Find an Eye Doctor.

Sudden vision loss needs same-day care. Call an eye doctor right away. If you also have a new headache, jaw pain when chewing, scalp tenderness, fever, or you are over 50 and feel unwell, go to the emergency department.

Medical disclaimer. This page is for general education. The patient section is not medical advice, and the clinician section is not a clinical practice guideline; neither replaces an examination, clinical judgment, or specialty consultation. If you have sudden vision loss, seek same-day care from an eye doctor or an emergency department. Information is current as of the “last reviewed” date.