Glaucoma

Glaucoma can damage the optic nerve before a person notices symptoms. The optic nerve carries visual information from the eye to the brain; once nerve fibers are lost, the resulting vision loss is generally irreversible. Eye pressure is the major modifiable risk factor, but glaucoma can occur even when pressure is in the statistically normal range. Early detection and pressure-lowering treatment help protect remaining vision.

Types of Glaucoma

Primary Open-Angle Glaucoma (POAG)

• Most common type (90% of cases)
• Drainage angle is open but doesn't function efficiently
• Develops slowly over years
• Usually no symptoms until advanced
• Affects peripheral vision first

Angle-Closure Glaucoma

Chronic angle-closure:

• Gradual narrowing of drainage angle
• May be asymptomatic initially

Acute angle-closure:

• Medical emergency
• Sudden, severe eye pain
• Headache, nausea, vomiting
• Halos around lights
• Red eye, blurred vision
• Requires immediate treatment

Normal-Tension Glaucoma

• Optic nerve damage despite normal eye pressure
• More common in certain populations
• May be related to blood flow issues
• Treatment still focuses on lowering IOP

Secondary Glaucoma

• Results from other conditions:
  • Eye injury
  • Inflammation
  • Steroid use
  • Advanced cataracts
  • Diabetes (neovascular glaucoma)

Symptoms

Early Glaucoma

• Usually no symptoms - which is why many people wonder if they could have glaucoma without knowing it
• Vision loss begins in peripheral (side) vision
• Central vision preserved until late stages

Advanced Glaucoma

• Tunnel vision
• Difficulty with peripheral awareness
• Problems navigating, especially in dim light
• Central vision affected in late stages

Acute Angle-Closure (Emergency)

Risk Factors

• Age over 40 (risk increases with age)
• Family history of glaucoma
• African, Asian, or Hispanic ancestry
• Elevated intraocular pressure
• Thin central cornea
• High myopia (nearsightedness) or hyperopia (farsightedness)
• Diabetes, hypertension, or heart disease
• Long-term corticosteroid use
• Previous eye injury

How Glaucoma Is Diagnosed

Comprehensive Eye Exam

• Tonometry-measures eye pressure
• Ophthalmoscopy-examines optic nerve
• Gonioscopy-evaluates drainage angle
• Perimetry (visual field test)-maps peripheral vision
• Pachymetry-measures corneal thickness

Advanced Imaging

• Optical coherence tomography (OCT)-measures nerve fiber layer thickness
• Optic nerve photography-documents appearance over time
• Heidelberg retinal tomography (HRT)-3D optic nerve analysis

Treatment

Treatment cannot restore lost vision but can prevent further damage.

Eye Drops

Common first-line drops:

Prostaglandin analogs (latanoprost, bimatoprost, travoprost)

• Most effective at lowering IOP
• Once daily dosing
• May darken iris and eyelashes

Beta-blockers (timolol)

• Reduce fluid production
• Avoid with asthma, heart conditions

Alpha agonists (brimonidine)

• Reduce production and increase outflow

Carbonic anhydrase inhibitors (dorzolamide, brinzolamide)

• Reduce fluid production

Combination drops (Simbrinza, Rocklatan)

• Multiple medications in one bottle
• Improve compliance

Newer agents

• Vyzulta (latanoprostene bunod)-nitric oxide-donating prostaglandin
• Pilocarpine-oldest glaucoma drug; still used for angle-closure
• Acetazolamide-oral carbonic anhydrase inhibitor for acute IOP reduction

Laser Treatment

Selective Laser Trabeculoplasty (SLT)

• Opens drainage channels
• Can be used as first-line treatment or when drops are insufficient
• Can be repeated

Laser Peripheral Iridotomy (LPI)

• Creates hole in iris
• Treats or prevents angle-closure
• Quick outpatient procedure

Surgery

For uncontrolled glaucoma:

Trabeculectomy

• Creates new drainage pathway
• Most effective surgical option
• Requires careful postoperative care

Glaucoma drainage devices

• Tube shunts that drain fluid
• For complex or refractory cases

Minimally invasive glaucoma surgery (MIGS)

• Newer, safer options
• Often combined with cataract surgery
• Less IOP reduction than traditional surgery

Living with Glaucoma

Medication Adherence

• Use drops exactly as prescribed
• Missing doses can lead to vision loss
• Set reminders or use drop dispensers
• Report side effects-alternatives exist

Regular Monitoring

• Eye exams every 3-12 months
• Visual field tests to track stability
• OCT imaging to monitor nerve health

Lifestyle Considerations

• Regular exercise may help lower IOP
• Avoid head-down positions for prolonged periods
• Inform other doctors about your diagnosis
• Wear medical ID if on multiple medications

Frequently Asked Questions

Can glaucoma be cured?

No, glaucoma cannot be cured, but it can often be controlled. With timely diagnosis and appropriate treatment, many patients maintain useful vision for years. Early detection is key.

Will I go blind from glaucoma?

With modern treatment and monitoring, most patients do not go blind. However, untreated or poorly controlled glaucoma can lead to significant vision loss. Adherence to treatment is crucial.

How often do I need eye exams?

After diagnosis, typically every 3-12 months depending on disease severity and stability. Your doctor will determine the appropriate interval.

Can I stop my eye drops if my pressure is normal?

No. Eye pressure is controlled because of the drops. Stopping medication will cause pressure to rise again. Glaucoma treatment is usually lifelong.

Does marijuana help glaucoma?

While marijuana can temporarily lower eye pressure, the effect is short-lived (3-4 hours), requiring frequent use. The side effects make it impractical, and conventional treatments are far more effective.

Is glaucoma hereditary?

There is a strong genetic component. First-degree relatives of glaucoma patients have 4-9 times higher risk. Family members should have regular eye exams.

References