Glaucoma: Symptoms and Medications

What Is Glaucoma?

• Goldman-Cecil Medicine, p. 4131

Types of Glaucoma

1. Primary Open-Angle Glaucoma (POAG) - Most Common

• Often asymptomatic until late in disease - this is why it is called the "silent thief of sight"
• First symptoms may be difficulty reading, loss of contrast sensitivity, or glare
• Peripheral visual fields are significantly reduced before the patient notices
• Most cases are detected only during routine eye exams (high IOP or high cup-to-disc ratio)

2. Acute Angle-Closure Glaucoma - Emergency

• Severe eye pain (may be poorly localized)
• Nausea and vomiting (can mimic acute abdomen)
• Blurred vision with halos around lights
• Red eye with a non-reactive, mid-dilated pupil
• Headache

• Corneal haziness/cloudiness
• Fixed, mid-dilated pupil
• Shallow anterior chamber
• Very high IOP (typically >30 mmHg, often >50 mmHg)
• Goldman-Cecil Medicine, p. 4132; Rosen's Emergency Medicine, p. 896

Medications for Glaucoma

Drug Classes and Their Agents

• Goldman-Cecil Medicine, p. 4131; Katzung's Basic & Clinical Pharmacology, p. 261

Drugs Used in Acute Angle-Closure Glaucoma (Emergency Box)

• Prostaglandins: latanoprost 0.005% - 1 drop
• Topical beta-blocker: timolol 0.5% - 1 to 2 drops
• Carbonic anhydrase inhibitor: acetazolamide 500 mg IV or orally
• Osmotic agent: mannitol 1-2 g/kg IV over 45 min (reserved if above fail within 1 hour)

• Topical alpha-2 agonist: brimonidine (alphagan) - 1 drop
• Miotics: pilocarpine 1-2%
• Topical steroid: prednisolone acetate 1% - 1 drop every 15-30 min x4, then every hour

Key Clinical Notes

• Timolol can absorb systemically from the eye in sufficient amounts to cause bradycardia, heart block, or bronchospasm in susceptible patients. Topical timolol may interact with oral verapamil to increase heart block risk.
• Betaxolol is beta-1 selective, potentially safer in asthma/COPD, but may still worsen pulmonary symptoms in some.
• Prostaglandin analogues (latanoprost, travoprost) are often first-line for chronic open-angle glaucoma due to once-daily dosing and efficacy.
• Laser trabeculoplasty can substitute for or supplement medications and may be used as first-line therapy in POAG.
• For acute angle closure, definitive treatment is laser peripheral iridotomy (within 24-48 hours), not medications alone.
• Medications are generally taken lifelong in chronic glaucoma.
• Goldman-Cecil Medicine; Katzung's Basic & Clinical Pharmacology; Rosen's Emergency Medicine

Recent Clinical Guidelines on Glaucoma Management (2024-2026)

1. American Academy of Ophthalmology (AAO) - Preferred Practice Patterns 2025

Primary Open-Angle Glaucoma (POAG) PPP 2025

• IOP reduction target: Reduce IOP 20-30% below baseline as a reasonable initial goal; adjust based on disease severity and course
• Risk factors now officially include: elevated IOP, older age, Black race/Latino ethnicity, family history, diabetes mellitus, low blood pressure/ocular perfusion pressure, myopia, thin cornea, low corneal hysteresis, disc hemorrhage, large cup-to-disc ratio
• Normal-tension glaucoma (IOP within normal range): IOP lowering is still beneficial
• Monitoring tools: Automated visual field at 30°, 24°, 10°; circumpapillary RNFL/macular ganglion cell layer imaging
• Treatment approaches (medical, laser, and surgical) are all valid - choice depends on individual patient factors
• Clinical trials confirm that lowering IOP reduces risk of developing POAG and slows progression

Primary Open-Angle Glaucoma Suspect PPP 2025

• Diagnosis requires consistently elevated IOP (ocular hypertension), suspicious optic nerve, RNFL thinning, or suspicious visual field defect
• Treatment is initiated when IOP is high and risk factors are present, or when conversion to POAG is detected

Primary Angle-Closure Disease PPP 2025

• Acute angle-closure crisis (AACC): Immediate IOP-lowering therapy (topical/systemic), followed by laser peripheral iridotomy (LPI), incisional iridectomy, or lens extraction
• Fellow eye: After AACC, the phakic fellow eye should undergo prompt prophylactic LPI due to high risk of developing AACC
• Long-term follow-up is required to monitor for progressive peripheral anterior synechiae (PAS) and glaucomatous optic neuropathy

2. European Glaucoma Society (EGS) - 6th Edition Guidelines (2026)

• AI integration: Major update on artificial intelligence for glaucoma diagnosis and monitoring
• Genetics: Expanded section on genetic risk factors and testing
• Childhood glaucoma: New dedicated content for pediatric glaucoma management
• Angle-closure disease: Updated management pathways
• Surgical approaches: Major revision including MIGS (minimally invasive glaucoma surgery)
• "Choosing Wisely" recommendations: Guidance on avoiding low-value interventions
• Patient perspectives: Incorporated patient engagement into clinical decision-making
• Cost-effectiveness analysis added to guide treatment choices
• Pan-European survey used to prioritize clinical questions addressed in the guideline

3. EGS Surgical Innovation Guide (2023-2024)

• Trabeculectomy remains the gold standard conventional surgery
• MIGS (Minimally Invasive Glaucoma Surgery): Growing evidence base; positioned as bridge between medications and conventional surgery
• Tube shunts as alternative to trabeculectomy in complex cases
• Emphasis on individualized surgical selection; no single procedure fits all patients

4. Finnish Current Care Guideline for Open-Angle Glaucoma (2024)

• Primary open-angle glaucoma
• Normal-tension glaucoma
• Pseudoexfoliative glaucoma

5. Key Supporting Evidence (High-Quality Meta-Analyses 2024-2025)

Selective Laser Trabeculoplasty (SLT) vs. Medications - Meta-Analysis 2024

• SLT achieved comparable IOP control to medical therapy at 2, 3, 6, and 12 months
• Medications had slightly better IOP control at 1 month only
• SLT group had significantly fewer glaucoma surgeries, fewer antiglaucoma medications needed, and fewer ocular adverse effects
• No significant differences in visual field, IOP fluctuation, or quality of life
• Conclusion: Supports SLT as a valid first-line alternative to drops - consistent with AAO 2025 PPP

Network Meta-Analysis of Glaucoma Medications - 2025

• PGFA + beta-blocker: Antagonism (reduces effectiveness by ~1.26 mmHg)
• PGFA + ROCK inhibitor: Antagonism (~0.84 mmHg reduction in benefit)
• PGFA + CAI (dorzolamide): Synergy (-2.05 mmHg additional benefit) - the best combination

ROCK Inhibitors - Systematic Review 2024

• Netarsudil (ROCK inhibitor) approved for IOP lowering
• Beyond IOP reduction, ROCK inhibitors have potential effects on other ocular structures
• Unexpected off-label benefits being explored in clinical research

Summary of 2024-2026 Guideline Trends