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PubMed This is a summary of 67 peer-reviewed journal articles Updated
Ophthalmology

Primary Angle-Closure Glaucoma Resource Guide

At a Glance

Primary Angle-Closure Glaucoma (PACG) is an eye condition where the eye's drainage system becomes physically blocked by the iris, causing dangerous pressure spikes. Early diagnosis with gonioscopy and appropriate treatment are essential to prevent permanent vision loss.

Welcome to the Primary Angle-Closure Glaucoma (PACG) Resource Guide. Being diagnosed with PACG or being told you are an “angle-closure suspect” can be frightening. This guide translates the complex medical science into clear, actionable information so you can confidently partner with your care team.

PACG is fundamentally a problem of “crowding” inside the eye. Unlike open-angle glaucoma, where the eye’s drain is simply slow, in PACG the drain becomes physically blocked by the iris, leading to dangerous spikes in eye pressure.

Use the following pages to navigate your journey and prepare for productive conversations with your doctors:

01

Validation & Orientation: Understanding Primary Angle-Closure Glaucoma

Learn what a primary angle-closure glaucoma (PACG) diagnosis means. Understand the anatomy of closed angles, treatment options, and why early action matters.

02

Symptoms & Warning Signs: Intermittent Attacks and Acute Crises

Learn the symptoms of primary angle-closure glaucoma (PACG). Understand intermittent attacks, acute crises, and why early warning signs matter for your vision.

03

Anatomy & Subtypes: The PACG Spectrum

Learn about the anatomy and subtypes of primary angle-closure glaucoma (PACG). Understand the three stages from PACS to PACG and what they mean for your vision.

04

Diagnosis & Testing: Why Gonioscopy is Mandatory

Learn why gonioscopy is the gold standard for diagnosing primary angle-closure glaucoma (PACG). Understand eye pressure spikes and how to avoid misdiagnosis.

05

Standard of Care Treatment & The EAGLE Trial Paradigm Shift

Explore primary angle-closure glaucoma (PACG) treatment options. Learn about the EAGLE trial, clear lens extraction versus laser LPI, and emergency care.

06

Medication Warnings: Drugs That Can Trigger an Attack

Learn which medications can trigger an acute angle-closure glaucoma attack. Understand the risks of antidepressants, cold medicines, and topiramate.

07

Monitoring & Long-Term Management

Learn about long-term management for primary angle-closure glaucoma (PACG). Understand target pressure, OCT testing, and how to protect your vision for life.

Common questions in this guide

What is Primary Angle-Closure Glaucoma (PACG)?
PACG is an eye condition caused by physical crowding inside the eye. Unlike open-angle glaucoma where the drain is just slow, in PACG, the eye's natural drainage system becomes physically blocked by the iris, which can lead to dangerous spikes in eye pressure.
Why is a gonioscopy necessary for diagnosis?
A simple eye pressure check is not enough to diagnose PACG. Your eye doctor must perform a mandatory test called a gonioscopy, which uses a special lens to look directly at the drainage angle of your eye and see if it is blocked.
What are the standard treatments for angle-closure glaucoma?
Modern treatment options focus on opening the blocked drainage angle to lower eye pressure. Based on findings like the EAGLE trial, standard treatments include laser therapy or clear lens extraction surgery to create more room inside the eye.
Can over-the-counter cold medicines trigger a glaucoma attack?
Yes, certain everyday medications can trigger a dangerous spike in eye pressure if you have narrow angles or PACG. These include common cold pills and certain antidepressants, like SSRIs, which is why your eye doctor must review your full medication list.
What should I do if I have a sudden glaucoma attack after hours?
Because an acute attack can happen suddenly and threatens your vision, you should ask your clinic who to contact for after-hours emergencies. True medical emergencies require immediate medical intervention to lower the pressure and save your sight.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Who is the best point of contact in your clinic if I experience sudden symptoms of an acute attack after hours?
  2. 2.What is the plan to coordinate my eye care with my primary care doctor and other specialists?
  3. 3.How will we determine whether my treatment plan needs to change over time?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

This guide is for informational purposes only and does not replace professional medical advice. Always consult your ophthalmologist or eye care provider about your specific condition, symptoms, and treatment plan.

Get notified when new evidence is published on primary angle-closure glaucoma.

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