After bilateral iridotomy most patients will be totally cured and will need no further medication and have no visual loss.
- A cause of a red eye needing urgent treatment
- Ophthalmological emergency
- Elevated intraocular pressure due to blockage of the drainage of aqueous from the anterior chamber
- Anything that dilates pupils can trigger it e.g. night time
- Anticholinergic medications or sympathomimetic medication which dilate the pupil
- Average age at presentation is 60 and prevalence increases thereafter
- Delay in treatment can lead to damage to the optic nerve and vision loss.
Precipitant: having the pupil half-way dilated
- Stress, excitement, anti cholinergic drugs
- Spending time in a dark place (such as a dimly lit restaurant)
- Medications that dilate the pupil e.g. Atropine like drugs.
- Seen in 1 of 1000 whites, 1 in 100 Asians, and 2-4 of 100 Eskimos
- Commoner in females because of their shallower anterior chamber
- Red painful eye which feels hard
- Pupil mid-dilated and fixed, Cloudy cornea
- Systemic symptoms - nausea and vomiting can distract
- Shallow peripheral anterior chamber
- Another eye has angle-closure glaucoma
- Cataract (which may be part of the cause)
- Injection of the conjunctiva with redness
- Gonioscopy, examination of anterior chamber angle
- Slit-lamp examination
- Automatic static perimetry
- Tonometry shows pressure usually > 30 mmHg even 60-70 mmHg
- IV Acetazolamide 500 mg to block the production of aqueous humor.
- IV Mannitol 20% 1-2 g/kg can be given to rapidly reduce the volume of aqueous humor.
- Topical Beta-Blocker (Timolol 0.5%) one drop to block the production of aqueous humor.
- Pilocarpine drops to constrict pupil and open up blocked canal
- Anterior chamber paracentesis (as emergency treatment)
- Laser iridectomy should be done in both eyes though not always at same time