Open Angle Glaucoma
Definition
Glaucoma: Disease causing death of optic nerve
Open angle: Gradual (chronic) blockage of some parts of trabecular meshwork in anterior chamber
NOTE: High intraocular pressure (IOP) is not required for diagnosis
Epidemiology
Risk Factors
Clinical Features
Symptoms
Signs
1st visit, check corneal thickness (corneal thickness may affect IOP reading)
1. Pressure
2. Fundoscope
3. Vision
Investigations
Imaging: Tonometry, gonioscope (look at irido-corneal angle), pachymetry, fundoscopy, perimetry
Management
Medical:
Surgical:
Source
Dr Tim Root, www.ophthobook.com, 2009
Glaucoma: Disease causing death of optic nerve
Open angle: Gradual (chronic) blockage of some parts of trabecular meshwork in anterior chamber
NOTE: High intraocular pressure (IOP) is not required for diagnosis
Epidemiology
- 80% of glaucoma
- Mostly above 40y
Risk Factors
- Age
- FHx
- Race (African American, Hispanics)
- High IOP
- Thin cornea
- Optic disc cupping (large vertical)
Clinical Features
Symptoms
- Peripheral vision loss not obvious
- Usually asymptomatic
Signs
1st visit, check corneal thickness (corneal thickness may affect IOP reading)
1. Pressure
- IOP > 22 mm Hg
2. Fundoscope
- Optic disc ratio > 0.5
- ISNT (inferior neural rim thickest, temporal thinnest)
3. Vision
- Perimetry (peripheral vision loss)
Investigations
Imaging: Tonometry, gonioscope (look at irido-corneal angle), pachymetry, fundoscopy, perimetry
Management
Medical:
- BB (dec aqueous humour production - watch out for CAD, COPD, asthma)
- Prostaglandin analogues (inc aqueous outflow - eg. Latanoprost. Sefx: longer lashes, change eye colour)
- Carbonic anhydrase inhibitor (Diamox)
Surgical:
- Trabeculectomy
- Laser ciliary body (last resort)
Source
Dr Tim Root, www.ophthobook.com, 2009