Overview
Glaucoma is a group of eye diseases in which elevated fluid pressure (intraocular pressure) in the eye damages the optic nerve and can lead to blindness. It is the second most common cause of blindness in the world.
It is present in 2-3% of people over age 40 in our country. It progresses insidiously; it narrows the visual field without symptoms. It is also known as the "silent thief."
Types
1. Open-angle glaucoma (most common, 90%):
- Slow drainage of fluid
- Progresses silently over years
- Usually no symptoms
2. Closed-angle glaucoma:
- Acute, medical emergency
- Sudden eye pain, vision loss
- Requires emergency treatment
3. Normal tension glaucoma:
- Normal eye pressure
- Still optic nerve damage
4. Congenital glaucoma:
- In infancy
- Congenital anatomical disorder
5. Secondary glaucoma:
- Due to another disease or medication (diabetes, cortisone)
Symptoms
Open-angle (insidious):
- Asymptomatic in early stage
- Slowly narrows visual field from the edges
- "Tunnel vision" develops
- In advanced stage, central vision also affected
- Blindness (if untreated)
Closed-angle (acute, emergency):
- Sudden severe eye pain
- Blurred vision
- Halos around lights (rainbow)
- Severe headache
- Nausea, vomiting
- Eye redness
- Pupil dilation
Congenital:
- Eye enlargement
- Excessive tearing
- Light sensitivity
- Cloudy cornea
Causes
Impaired drainage of aqueous humor fluid inside the eye:
- Trabecular meshwork blockage (open-angle)
- Closure of iris angle (closed-angle)
- Anatomical abnormalities
- Nerve blood flow problems (normal tension)
Risk Factors
- Age (over 40, especially over 60)
- Family history (strongest factor)
- Ethnicity: African (open-angle), Asian (closed-angle)
- High eye pressure
- Diabetes
- High myopia or high hyperopia
- Previous eye injury, surgery
- Long-term cortisone use (especially eye drops)
- Migraine
- Low blood pressure, sleep apnea
- Thin cornea
Complications
- Narrowing of visual field
- Permanent blindness (if untreated)
- Significant decrease in quality of life
- Falls, accidents
- Social isolation
- Loss of independence
When to See a Doctor
Routine:
- Eye examination starting at age 40
- Earlier if family history exists (age 30)
- More frequent follow-up if risk factors present
Emergency (closed-angle glaucoma):
- Sudden severe eye pain
- Sudden blurred vision
- Halos around lights
- Severe headache + nausea
- Permanent blindness if not treated within hours
Screening Recommendations
- Age 40: first eye examination
- Age 40-54: every 2-4 years
- Age 55-64: every 1-3 years
- Over 65: every 1-2 years
- Those with family history or risk factors: more often
Diagnosis and Treatment
Diagnosis:
- Intraocular pressure (tonometry)
- Visual field test (perimetry)
- Optic nerve examination
- OCT (optical coherence tomography) - nerve fiber analysis
- Gonioscopy (drainage angle)
- Pachymetry (corneal thickness)
- Visual evoked potential
Treatment:
Goal: Lower intraocular pressure
1. Eye drops (usually first choice):
- Prostaglandin analogs: Latanoprost, travoprost, bimatoprost (most common, once daily)
- Beta blockers: Timolol, betaxolol
- Carbonic anhydrase inhibitors: Dorzolamide, brinzolamide
- Alpha-2 agonists: Brimonidine, apraclonidine
- Rho kinase inhibitors: Netarsudil (new)
- Cholinergics: Pilocarpine (older, rarely used)
- Combination medications
2. Laser treatment:
- SLT (selective laser trabeculoplasty): Open-angle glaucoma
- Laser peripheral iridotomy: To prevent closed-angle glaucoma
- Cyclophotocoagulation: Severe cases
3. Surgery:
- Trabeculectomy: Traditional
- Tube shunt surgery (Ahmed, Baerveldt)
- Minimally invasive glaucoma surgery (MIGS): iStent, Hydrus, XEN
- For closed-angle: lens surgery
4. Acute closed-angle glaucoma (emergency):
- Pilocarpine, acetazolamide (IV)
- Beta blocker, hyperosmotic
- Laser iridotomy
Prevention and Lifestyle
Glaucoma cannot be fully prevented; however:
Early diagnosis:
- Regular eye examinations (most critical)
- More frequent if family history exists
- Inform your doctor of risk factors
Lifestyle:
- Heart-healthy lifestyle
- Regular exercise (lowers eye pressure)
- Maintain a healthy weight
- Control your diabetes
- Quit smoking
- Limit caffeine (excessive amounts can raise eye pressure)
- Keep head slightly elevated when sleeping
- Avoid excessive fluid intake (in a short time)
- Manage your stress
- Use eye protection (prevent injury)
Treatment compliance:
- Use your drops regularly
- Report side effects to your doctor
- Attend regular follow-up examinations
- Do not accidentally skip your medications
- Stay in continuous follow-up (lifelong)
Glaucoma is a treatable disease; however, damage that has occurred is irreversible. Early diagnosis preserves vision.