Acute angle closure glaucoma is a sudden and severe eye condition that necessitates immediate medical attention. This condition arises when the eye’s drainage system becomes abruptly blocked, leading to a rapid and dangerous increase in internal eye pressure. Prompt intervention is required to prevent permanent vision loss.
Understanding Acute Angle Closure Glaucoma
Acute angle closure glaucoma occurs when the “angle” within the eye, formed by the iris (the colored part) and the cornea (the clear front surface), suddenly narrows or closes. This angle is where a clear fluid, known as aqueous humor, normally drains out of the eye. When this drainage pathway is obstructed, the aqueous humor accumulates, causing the intraocular pressure (IOP) to rise rapidly.
The rapid increase in intraocular pressure can reach levels as high as 60 to 80 mm Hg, significantly higher than the typical range of 10 to 20 mm Hg. This elevated pressure puts immense strain on the optic nerve, a bundle of nerve fibers at the back of the eye that transmits visual information to the brain. Sustained high pressure can damage the delicate nerve fibers, leading to irreversible vision loss. In many cases, an enlarged lens, which naturally grows with age, can push the iris forward, contributing to the narrowing of this angle.
Recognizing the Symptoms
Individuals often experience intense eye pain, which may spread to the forehead and be accompanied by a headache. Vision can become blurred, and some people report seeing colored rings or halos around lights.
Additional symptoms frequently include nausea and vomiting, which can sometimes lead to misdiagnosis as a gastrointestinal or neurological issue. The affected eye may also appear red, and the pupil might be fixed in a mid-dilated position, not reacting normally to light.
Emergency Medical Interventions
Upon presentation in an emergency setting, the primary goal is to rapidly lower the high intraocular pressure to protect the optic nerve. This initial management often involves a combination of eye drops and oral or intravenous medications. Miotics, such as pilocarpine, are eye drops used to constrict the pupil, which can help pull the iris away from the drainage angle. Other topical medications include beta-blockers like timolol, and alpha-agonists such as brimonidine, which work to reduce aqueous humor production or increase its outflow.
Carbonic anhydrase inhibitors, like acetazolamide, are administered orally or intravenously to decrease fluid production within the eye. Osmotic agents, such as mannitol, may also be given intravenously to draw fluid out of the eye, further reducing pressure. These medications are temporary measures aimed at stabilizing the eye and reducing pressure to a safer level.
Definitive Treatment Procedures
Once the acute phase of high intraocular pressure is managed, definitive procedures are performed to prevent future attacks and ensure long-term fluid drainage. The most common and effective treatment is laser peripheral iridotomy (LPI). In this outpatient procedure, a laser creates a small hole in the iris. This opening allows aqueous humor to flow, bypassing the blocked angle and creating a permanent drainage pathway.
If LPI is not sufficient, or if the eye’s natural lens is significantly contributing to the angle closure, surgical options may be considered. A peripheral iridectomy, a surgical procedure, involves creating a small opening in the iris. Additionally, lens extraction, commonly known as cataract surgery, can be performed. Removing the enlarged natural lens creates more space within the eye, widening the drainage angle.
Post-Treatment Care and Follow-Up
Following definitive treatment for acute angle closure glaucoma, ongoing post-treatment care and regular follow-up appointments are necessary. These appointments typically involve monitoring intraocular pressure and assessing the health of the optic nerve to detect any signs of damage or recurrence. Due to the anatomical similarities between both eyes, there is a significant risk that the unaffected eye may also experience an acute angle closure attack. Therefore, preventative treatment, often an LPI, is commonly recommended for the other eye to reduce this risk. Patients should remain vigilant for any symptoms that might suggest a recurrence or complication, ensuring they seek prompt medical attention if concerns arise.