A condition of the eyes wherein internal pressure suddenly rises, acute glaucoma is characterized by reduced vision, pain and redness. The said eye disorder also exhibit symptoms such as nausea, headache and abdominal pain. If left untreated, it could result to further eye damage.
Also called acute closed angle glaucoma, this eye disorder has two types: primary, secondary and congenital glaucoma. Primary or chronic glaucoma is the most common type.
Causes of Acute Glaucoma
In order to fully understand the aetiology of this eye condition, it is recommended that you first understand the function of the eye fluid. It is important for the eye to maintain its shape for the accurate focusing of light rays into the retina. This is actually accomplished by a jelly-like substance called “vitreous humour” which fills most parts of the eye and the watery “aqueous humour” in the front portion of the eye
The aqueous humour circulates through the eye front and drains via the trabecular meshwork found at the iris base. This fluid production as well as drainage is continuous.
Sudden blockage in the draining of the eye fluid could cause the increase in internal pressure in the eye. As long as the fluid is not drained, the pressure continues to build up. The blockage can actually be attributed to the proximity of the iris to the eye’s lens resulting to the fluid getting stuck and making the iris bulge forward.
As for the reason for the blockage, it can be due to the following:
- Area near iris base is very narrow making it easier to get blocked
- Swollen lens which could result to a shallow anterior chamber or narrow drainage angle. This will make the person more at risk for glaucoma.
- Iris muscle causes pupil to enlarge and bulge which blocks the fluid flow especially if the immediate area has narrowed.
- Enlargement of pupils due to sudden excitement, medication and dim lights can also result to fluid flow being blocked.
Acute Glaucoma Triggers
Since it was mentioned that dim lighting can cause acute glaucoma, it is not surprising that it occurs most commonly during the night time. A simple activity such as watching a football game can trigger the symptoms due to combination of excitement and dim lights.
Individuals who are at risk of acute glaucoma should also be cautious when taking certain medications for it could trigger the onset of this eye condition. Although the risk involved in suffering from this eye condition is relatively small, it certainly would not hurt to be careful. Among the medications considered as triggers include:
- Anti-depressants (SSRI or tri-cyclic types)
- Eye drops – dilates the pupils and usually used during routine checkups
- Phenothiazines ( for treatment of nausea and vomiting)
- Ipratropium (for asthma treatment)
- Chlorpheniramine, ranitidine and cimetidine (for stomach ulcers)
- Other medications for allergy treatments and general anaesthetics
Another possible trigger is lying face down, such as in spinal operations, for a prolonged period for this could affect eye fluid.
Risk Factors for Acute Galucoma
Certain risk factors should be considered to know if you are at risk for acute glaucoma.
- Individuals aged 40 years old and above
- Individuals who are long-sighted
- Eskimo, Southeast Asian race
Common Symptoms of Acute Galucoma
Unfortunately, most of the symptoms associated with acute glaucoma start without warning. They include:
- Sudden pain in your eyes usually severe
- Reduced vision accompanied by haloes round light sources
- Headache due to eye pain
- Nausea and vomiting due to eye pain
- Pupils appear larger than normal
- Clear portion of the eye will look hazy or milky
Again, these symptoms usually appear after the acute glaucoma is triggered due to certain lighting conditions or medications. If you experience any of the above symptoms, it is important that you seek medical attention to prevent worsening of the eye condition.
Warning Signs of Acute Glaucoma
In most cases, acute glaucoma appears suddenly and you might not be able to immediately recognize the danger signs. Such symptoms that you should look out for include: seeing rainbows or haloes around lights, eye pain and blurred vision. They could be experienced intermittently and could even disappear after sleep. Make sure you contact your doctor at once to prevent further attacks.
Diagnosis and Treatment
Since acute glaucoma may be experienced without warning, diagnosis is usually made after the appearance of the symptoms. An eye specialist will confirm the eye condition after a detailed examination using a slit lamp as well as a specific test that will measure eye pressure.
After confirmation, the eye specialist will immediately try to lower the pressure and reduce fluid build up by using:
- Eye drops with beta-blocker and steroids
- Acetazolamide injection
Secondary treatment will usually involve:
- Painkillers or anti-sickness drugs
- Mannitol – to reduce fluid build up
- Eye drops (brimonidine, brinzolamide or pilocarpine
- Lying on back to encourage fluid drainage
Further treatment for prevention is recommended in order to ensure that the eye condition will not come back. Possible treatments include:
- Laser treatment or peripheral iridotomy – creation of two small holes near the iris to promote fluid drainage; usually the preferred treatment there is no eye surgery involved; holes will remain unnoticeable
- Surgical treatment or surgical iridectomy – creation of triangular holes in the iris for fluid drainage; holes will be quite visible and will appear like a black triangle at the iris edge
- Another surgery similar to cataract operation – removal of the eye lens and replaced by artificial lens
Most eye specialist will recommend any of the surgical treatment in order to prevent the other eye from getting acute glaucoma. Some patients will be prescribed eye drops as a part of their long-term treatment to ensure that eye pressure is kept in control.
Complications of Acute Glaucoma
Without proper management and treatment, individuals diagnosed with acute glaucoma can experience blood vessel and nerve damage in their eyes due to the high pressure. This could likely lead to reduced vision or, in some extreme cases, even blindness.
Outlook of Acute Glaucoma Patients
With immediate treatment and proper management, the outlook for acute glaucoma patients is quite good. The affected eye can easily recover and even return to normal after laser surgery treatment. Some individuals are even allowed to drive after recovery even if vision is permanently reduced in the affected eye. For those who were diagnosed with acute glaucoma on both eyes, the law requires you to inform the DVLA (Driver and Vehicle Licensing Authority).
Prevention of Acute Glaucoma
Individuals who experience narrowing in the area wherein eye fluid usually drains are more likely to suffer from acute glaucoma. Such narrowing, referred to as narrow drainage angle or shallow anterior chamber can be detected during standard eye examination. Your eye specialist will immediately inform you of the risk involved and might advice you to be careful with eye drops and other medications.
If you are considered to be at high risk for acute glaucoma, a laser surgery treatment may be recommended to prevent the condition from worsening.
Considering the seriousness of this particular eye condition, all individuals should pay attention to symptoms such as vomiting, red eye, reduced vision and eye pain. Experiencing any of these symptoms can signal acute glaucoma and you should immediately get checked. Make sure you take note of the instance or situation when you experienced the symptoms such as dim lightning or after taking certain medications> Inform your eye doctor about this in order to identify the possible triggers and allow for easier diagnosis.