Glaucoma is a group of optic nerve diseases in which progressive damage to the optic nerve causes irreversible peripheral visual field loss. Elevated intraocular pressure (IOP) is the main modifiable risk factor, but damage can occur at normal pressure. Aqueous humor is made by the ciliary body, flows through the pupil, and drains through the trabecular meshwork (conventional route) and the uveoscleral pathway. When drainage fails, IOP rises.
| Type | Mechanism | Onset | Presentation |
|---|
| Primary open-angle glaucoma (POAG) — most common | Gradual resistance to outflow through the trabecular meshwork; angle is open | Slow, painless, no early symptoms | Gradual loss of peripheral vision ("tunnel vision"); found on screening |
| Acute angle-closure glaucoma | The iris blocks the drainage angle suddenly (often when the pupil dilates in dim light or with drugs) | Sudden | Severe eye pain, headache, nausea/vomiting, blurred vision, halos around lights, red eye, fixed mid-dilated pupil, hazy cornea, rock-hard eye |
| Secondary glaucoma | Due to uveitis, steroids, trauma, neovascularization | Varies | Depends on cause |
Normal IOP is about 10–21 mmHg; in acute angle closure, IOP is often above 40 mmHg.
Glaucoma risk factors: raised IOP, age over 60, family history, Black or Hispanic ancestry (open-angle), Asian ancestry and hyperopia (angle-closure), high myopia (open-angle), diabetes, long-term corticosteroid use, thin cornea.
Cataract is clouding of the lens, most often from aging (protein changes). Other causes: diabetes, smoking, UV exposure, long-term corticosteroids, eye trauma, radiation, congenital infection. Light scatters through the cloudy lens, reducing clarity and contrast.
Open-angle glaucoma: usually none early; later, missed objects at the side, bumping into things, difficulty with night driving. Optic disc cupping on exam.
Acute angle closure: see table above — this is an emergency.
Cataract
- Painless, gradual blurred or cloudy vision
- Glare and halos, especially with night driving or bright sun
- Faded colors, reduced contrast, frequent change of eyeglass prescription
- Absent or reduced red reflex; lens appears cloudy (white or yellow-brown) when advanced
| Test | Purpose |
|---|
| Tonometry | Measures IOP — in suspected acute angle closure, measure promptly while notifying the provider; do not delay treatment |
| Gonioscopy | Views the drainage angle (open vs. narrow/closed) |
| Ophthalmoscopy / OCT of optic nerve | Cupping and nerve fiber loss |
| Perimetry (visual field test) | Maps peripheral field loss; tracks progression |
| Pachymetry | Corneal thickness (thin cornea = higher risk; affects IOP readings) |
| Slit lamp / visual acuity / glare testing | Cataract grading and functional impact |
| Biometry | Measures eye length to choose the intraocular lens (IOL) power before cataract surgery |
Open-angle glaucoma — lifelong IOP lowering
- Prostaglandin analogs (PGAs) first-line eye drops: latanoprost, travoprost, bimatoprost, latanoprostene bunod — increase uveoscleral outflow, once daily in the evening
- Beta-blockers (timolol) — reduce aqueous production
- Alpha-2 agonists (brimonidine) — reduce production and increase outflow
- Carbonic anhydrase inhibitors — topical dorzolamide, brinzolamide; oral acetazolamide
- Rho kinase inhibitor (netarsudil) — increases trabecular outflow
- Laser trabeculoplasty (selective, SLT) — an accepted first-line alternative to drops
- Surgery: trabeculectomy, tube shunts, minimally invasive glaucoma surgery (MIGS)
Acute angle-closure glaucoma — emergency
- Rapidly lower IOP: topical beta-blocker, alpha-2 agonist, IV or oral acetazolamide, and IV mannitol if needed
- Pilocarpine (miotic) after pressure starts to fall, to pull the iris away from the angle
- Laser peripheral iridotomy is the definitive treatment; the other eye is often treated prophylactically
Cataract
- Early: updated glasses, brighter lighting, anti-glare sunglasses
- Surgery when vision limits daily activities: phacoemulsification with IOL implant, usually outpatient under topical or local anesthesia
- Posterior capsule opacification (a later clouding behind the IOL) is treated with YAG laser capsulotomy
Drug safety — glaucoma drops
| Class | Adverse effects | Cautions / contraindications |
|---|
| PGAs | Darkening of iris color (permanent), eyelid skin darkening, eyelash growth, eye redness, periorbital fat loss | Caution with active uveitis, HSV keratitis history; risk of cystoid macular edema (caution after cataract surgery) |
| Beta-blockers (timolol) | Systemic absorption → bradycardia, bronchospasm, hypotension, fatigue, masked hypoglycemia | Avoid in asthma, severe COPD, bradycardia, heart block, decompensated heart failure |
| Alpha-2 agonists (brimonidine) | Dry mouth, fatigue, allergic conjunctivitis | Contraindicated in infants and young children (CNS and respiratory depression); do not use with MAO inhibitors |
| Carbonic anhydrase inhibitors | Topical: stinging, bitter taste. Oral acetazolamide: paresthesia, hypokalemia, metabolic acidosis, kidney stones, fatigue | Sulfonamide allergy caution; monitor potassium; avoid in severe kidney or liver disease |
| Rho kinase inhibitor | Red eye, corneal deposits | — |
| Miotics (pilocarpine) | Small pupil → dim vision at night, brow ache, blurred vision | Rare retinal detachment; avoid in uveitis |
| Mannitol (IV) | Fluid overload, electrolyte shifts | Monitor urine output, heart failure, kidney function |
Drugs that can trigger angle closure in susceptible clients: anticholinergics, some antihistamines and decongestants, tricyclic antidepressants, topiramate, mydriatic eye drops.
Listed in priority order.
- Acute angle closure — act fast
- Recognize the presentation; notify the provider immediately and measure IOP promptly — do not delay treatment
- Give IOP-lowering drugs as ordered; treat pain and vomiting (vomiting raises IOP)
- Keep the client in a quiet, semi-reclined position; avoid dark rooms that dilate the pupil
- Cataract surgery — preoperative
- Assess systemic health: glucose control, blood pressure, anticoagulant use, ability to lie flat
- Ask about alpha-1 blockers (tamsulosin) — they cause intraoperative floppy iris syndrome; tell the surgeon
- Instill dilating and anti-inflammatory drops as ordered; confirm the correct eye
- Cataract surgery — postoperative
- Eye shield, especially at night; assess pain (usually mild) and vision
- Report severe pain, sudden vision loss, increasing redness, or discharge — possible endophthalmitis, an emergency
- Monitor for raised IOP (pain, nausea, headache), and flashes/floaters (retinal detachment)
- Eye drop administration (see Client Education)
- Safety — low vision and dilated pupils increase fall risk; bright, even lighting; high-contrast markings
- Adherence support — glaucoma drops prevent loss that cannot be recovered; simplify regimens, use reminders
Eye drop technique
- Wash hands; check the drug and eye
- Tilt head back, pull down the lower lid, instill one drop into the pocket without touching the tip to the eye
- Close the eye gently and press the inner corner (punctal occlusion) for about 2–3 minutes — reduces systemic absorption (important for beta-blockers) and keeps the drug in the eye; do not blink rapidly or squeeze
- Wait at least 5 minutes between different drops; drops before ointments
- Remove soft contact lenses before drops and wait about 15 minutes before reinserting (preservatives)
Glaucoma
- Glaucoma is silent at first and vision lost cannot be restored; keep regular checkups and use drops for life, even without symptoms
- Tell every provider you have glaucoma; ask before taking cold remedies or sleep aids if you have narrow angles
- Seek emergency care for sudden eye pain, halos, headache, and vomiting
- Family members should have eye exams
After cataract surgery
- Do not rub or press on the eye; wear the shield at night as instructed (commonly about a week)
- Avoid heavy lifting, straining, and bending with the head below the waist in the early period, as instructed by the surgeon
- Do not sleep on the operated side; keep water and soap out of the eye; avoid swimming and eye makeup for the period advised
- Use prescribed antibiotic and anti-inflammatory drops on schedule
- Wear sunglasses outdoors
- Report pain not relieved by analgesics, decreasing vision, flashes, floaters, or a curtain
Living with cataract before surgery: bright lighting, high-contrast colors (dark text on white paper), anti-glare lenses, avoid night driving.
| Complication | What to watch for |
|---|
| Acute angle closure | Sudden pain, halos, vomiting, fixed mid-dilated pupil |
| Endophthalmitis (post-op) | Severe pain, rapid vision loss, redness, hypopyon — usually within days |
| Raised IOP after surgery | Pain, nausea, headache |
| Retinal detachment | Flashes, floaters, curtain (weeks to months after surgery) |
| Posterior capsule opacification | Gradual blurring months to years later — YAG laser |
| Cystoid macular edema | Blurred central vision weeks after surgery |
| Progressive glaucoma | Worsening fields despite treatment — review adherence |
- Open-angle glaucoma: painless, no early symptoms, irreversible peripheral loss — screening matters
- Acute angle closure: eye pain, headache, vomiting, halos, fixed mid-dilated pupil — emergency: notify the provider immediately and measure IOP promptly; do not delay treatment
- PGAs are first-line; they increase uveoscleral outflow; cause iris darkening and eyelash growth
- Timolol: bradycardia and bronchospasm — avoid in asthma and heart block; press inner canthus
- Brimonidine: not for infants; acetazolamide: hypokalemia, paresthesia, sulfonamide caution
- Avoid anticholinergics and mydriatics in narrow angles
- Cataract: painless blurred vision, glare, absent red reflex
- Cataract post-op: no rubbing, shield at night, avoid straining; report pain and vision loss (endophthalmitis)
- Tamsulosin → floppy iris syndrome — tell the surgeon
- Before surgery: confirm control of diabetes and hypertension
- Glaucoma risk: high IOP, age, family history, high myopia, steroid use
Country Notes
United States
- Glaucoma is a leading cause of irreversible blindness, with higher open-angle risk in Black and Hispanic adults; Medicare covers a glaucoma exam once every 12 months for high-risk groups (diabetes, family history of glaucoma, African Americans aged 50 and older, Hispanics aged 65 and older).
Philippines
- Cataract is the leading cause of blindness, and many surgeries are delivered through outreach and charity programs; untreated bilateral cataract is common in rural older adults.
- Angle-closure glaucoma is relatively more common in Asian populations than in Western populations; teach the acute warning signs.