Glaucoma: SYMPTOMS & MANAGEMENT
Definition
Glaucoma is a group of eye diseases characterized by progressive optic neuropathy associated with increased intraocular pressure (IOP) that leads to visual field loss and blindness if untreated.
Glaucoma is also known as the "silent thief of sight" or "silent blinder" because it can have no noticeable symptoms in the early stages.
Glaucoma is a chronic eye disease that damages the optic nerve, which can lead to vision loss. It's the second most common cause of blindness in the United States.
Common Symptoms:
- Blind spots in your peripheral vision
- Seeing halos around lights
- Redness in your eye
- Eye that looks hazy
- Upset stomach or vomiting
- Eye pain
- Severe headache
Causes & Classification
1. Primary Glaucoma
- Primary Open-Angle Glaucoma (POAG): Open angle with increased resistance to aqueous outflow.
- Primary Angle-Closure Glaucoma (PACG): Angle obstruction, leading to sudden IOP elevation.
2. Secondary Glaucoma
- Neovascular Glaucoma: Due to diabetic retinopathy or CRVO.
- Pigmentary Glaucoma: Pigment blocks the trabecular meshwork.
- Steroid-Induced Glaucoma: Prolonged steroid use raises IOP.
3. Congenital Glaucoma
- Present at birth due to anterior segment abnormalities.
- Signs: Enlarged cornea, excessive tearing, light sensitivity.
Signs & Symptoms
Primary Open-Angle Glaucoma (POAG)
- Gradual vision loss (peripheral to central).
- Optic disc cupping (Cup:Disc ratio >0.6).
Primary Angle-Closure Glaucoma (PACG)
- Severe eye pain, headache, nausea, vomiting.
- Hazy cornea, mid-dilated non-reactive pupil.
- Markedly high IOP (>40 mmHg).
Investigations
- Tonometry: Measures IOP.
- Gonioscopy: Assesses angle status.
- OCT: Detects optic nerve damage.
- Fundoscopy: Evaluates optic disc cupping.
Treatment & Management
1. Medical Therapy (IOP-Lowering Drugs)
- Prostaglandin Analogs: Latanoprost, Bimatoprost, Travoprost
- Beta-Blockers: Timolol, Betaxolol
- Alpha Agonists: Brimonidine, Apraclonidine
- Carbonic Anhydrase Inhibitors: Acetazolamide, Dorzolamide
- Miotics: Pilocarpine (used in acute angle closure)
2. Surgical & Laser Therapy
- Laser Trabeculoplasty: Increases outflow (for POAG).
- Laser Peripheral Iridotomy: Used in PACG to open the angle.
- Trabeculectomy: Creates an alternative drainage pathway.
3. Emergency Treatment for Acute Angle Closure Glaucoma
- IV Acetazolamide (500 mg stat) - reduces IOP.
- Topical Timolol + Brimonidine + Pilocarpine - decreases IOP.
- Mannitol IV - hyperosmotic agent for critically high IOP.
- Definitive Treatment: Laser Peripheral Iridotomy
Summary
- Glaucoma is an optic neuropathy caused by increased IOP.
- POAG progresses slowly, while PACG is an emergency.
- Diagnosis: IOP measurement, gonioscopy, OCT, visual field testing.
- Treatment: Eye drops, laser therapy, surgery (if needed).