Acute Angle-Closure Glaucoma Chrissy Truchok

Overview Glaucoma One of the most common causes of blindness in United States Damage occurs to optic nerve causing vision loss and blindness Most common types are Open-Angle and Closed- Angle Glaucoma Acute angle closure glaucoma is one of the leading causes of blindness in the US. The two most common types are open angle and closed angle glaucoma. Overtime, damage to the optic nerve will occur which in turn causes the blindness. The fluid found in the eye, called aqueous humor, is responsible for providing the eyes with vital nutrients and also maintaing the correct intra ocular eye pressure in the eye chamber. (Angle-Closure, 2015)

Clinical Manifestations Closed-Angle Glaucoma Medical Emergency Fluid in the eye is unable to empty through its usual pathways Pressure builds up damaging the optic nerve The aqueous humor has a normal drainage routine from the eye, which also keeps the intra ocular pressure at a normal level. However if something begins to obstruct these drainage ducts and causes the fluid emptying to slow or even stop, that’s when big problems can occur. Angle closure glaucoma is considered a medical emergency and needs to be evaluated and cared for quickly once the symptoms begin.

Pathogenesis Fluid found in the eye is called aqueous humor Helps to maintain normal eye pressure Normal eye pressure is 12-22 mm Hg (Angle-Closure, 2015) When something begins to obstruct the drainage canals, aqueous humor builds up and will lead to an increase in intraocular pressure So as I said before, the fluid found in the eye helps to maintain a normal eye pressure, which is 12-22 mm of mercury. We will begin to see signs and symptoms as the fluid begins to back up. In closed angle glaucoma, the fluid does back up very quickly which is the big reason it is a medical emergency. (Primary Angle, 2001)

In many cases, the iris becomes bunched up over the drainage canals, causing the backup In this picture you can see how the iris would become kind of bunched up over the drainage canals to prevent the fluid from draining. The arrow is showing the way that the fluid flows out of the eye, so any little bit of movement from the iris can really throw off the whole process. (Glaucoma, 2015)

Causes One of the greatest causes of acute-angle closure is a sudden dilation of the pupils Medications causing the pupils to dilate suddenly Entering a dark room The biggest cause of angle closure glaucoma would be a sudden dilation of the pupils, which is really kind of scary because this happens to everyone so frequently throughout the day. There are different eye drops that can cause the pupils to dilate, like the kind you get at the ophthalmologist, and also some other prescription eye drops. Another major cause would be quickly entering a dark room, causing the pupils to dilate. This disease is not as common as the open angle glaucoma, so there's no need to be worried every time you enter a dark room, its just something to think about if a patient or even yourself are experiencing more severe glaucoma like symptoms.

Symptoms Sudden onset of: Severe headache Eye pain Blurred vision Eye redness Halos or rainbows around lights One of the key things to remember in closed angle glaucoma is that the symptoms are sudden and fairly severe. They include severe headaches, eye pain, blurred vision, eye redness and halos or rainbows around the lights. When trying to determine between open or closed angle glaucoma, remember that open angle is a slow onset and they usually don’t experience eye pain or halos around the lights. These patients may also present with nausea and vomiting due to the severe headache and eye pain.

Upon Presentation… Ask patient about family glaucoma history Obtain current medication list When a patient is presenting with these symptoms, it is important to get the history about what is going on and also their family history. As providers we should ask the patient things like what were the precipitating factors, does anything alleviate the pain and also how long these symptoms have been going on for. A family history should be obtained, because this disease does tend to run in families. If someone in the immediate family has glaucoma or angle closure glaucoma, the patient is at a higher risk for developing it as well. African Americans and those over 60 years old are at a greater risk for developing this type of glaucoma too. Also something to make note of, if a patient does experience this in one eye, chances are highly likely that they will develop it in the other eye as well. Double check the patients medication list for any meds that could potentially dilate the pupils as well. (Primary Angle, 2001)

Diagnosis Tonometry Test Used to measure intra ocular pressure Tonometry testing is one of the major tests used to check for angle closure glaucoma. This test is used specifically to check the intra ocular pressure of the eyes. For this test, the eye is numbed and an orange dye is placed on the front of the eye. A slit lamp is held in front of the eye, then slowly pressed onto the cornea. The cornea will then have pressure applied to it, and the amount of pressure that is needed to flatten the cornea will determine the intraocular pressure measurement. If the measure is high, it’s a very good indicator that they are experiencing closed angle glaucoma. Along with testing intra ocular pressure in emergent situations, tonometry testing is a good way to check if patients are at a high risk for developing glaucoma. They can do this on their yearly vision checkups to keep a close eye, especially if they have a glaucoma family history. (Five Common, n.d.)

Diagnosis Perimetry Test Used to test peripheral vision The Perimetry test is also another test useful in diagnosing this type of glaucoma. This test provides more in-depth information on the peripheral fields. It can help determine visual field damage and aid in the conclusive diagnosis of angle closure glaucoma. This test is fairly simple for both the patient and examiner to perform, the patient looks straight ahead and will let the examiner know when they see a light moving in their peripheral fields. (Shah, Bowd, Weinreb & Sample, 2006)

Diagnosis Gonioscopy Measures angle where iris meets the cornea Gonioscopy is a test to measure the angle where the iris meets the cornea. This then tells the examiner if it is open and wide or narrow and closed. This looks at the area that the aqueous humor drains from specifically, so we can see what type of glaucoma is present. For this procedure the eye is numbed and a small lens is placed in front of the eye so a small beam of light can shine into the eye and make the anterior chamber visible. When assessing the eye, we are not able to see those structures with just a pen light so this test can help finalize the diagnosis of angle closure glaucoma as well. (Shah, Bowd, Weinreb & Sample, 2006)

Differential Diagnosis Optic Neuritis Patient will also experience color vision loss and flashing lights Cataracts Patients experience more of a gradual vision loss Main determining factor for both of these diseases is that the IOP will not be elevated! Two of the main and in my opinion most common differential diagnosis would be optic neuritis and cataracts. Both of these present with similar symptoms of angle closure glaucoma so they are easy to mistake. An MRI can help determine the diagnosis of optic neuritis, along with the differential symptoms such as a loss of color vision and flashing lights. When a patient presents with cataracts, they usually have had these problems build up over time. They will experience more of a gradual vision loss and more gradual onset of problems. A slit lamp exam can be performed to confirm any cataract suspicions. The main determining factor for both of these is that the intra ocular pressure will not be elevated.

Treatment Lower intra ocular pressure immediately Eye drops Surgery The main goal of treatment for angle closure glaucoma is to open the blocked drainage canals. Relief can come almost immediately after opening these canals back up. Laser surgery can be performed to remove the part of the iris or whatever else may be blocking the canal. Topical beta blocker eye drops can also be given to help decrease the amount of fluid by the eye. Cholinergics can be given to increase the amount of drainage from the eye, so if there isn't a full block, these drugs are good alternatives to surgery. Eye drops are the first line treatment, however if it is a complete block, surgery will be needed immediately. (Primary Angle, 2001)

Outcomes Vision loss can be prevented Encourage yearly appointments If an attack is caught early, vision loss can be prevented and no further harm to the eyes will occur. However if we do misdiagnose or under treat, that is when permanent adverse effects will happen. If a patient does have this type of glaucoma, they will need to stay on medications to keep their intra ocular pressure within the normal range, and they will also need yearly IOP screenings. Angle closure glaucoma is a very serious condition, so as providers we really need to be on the look out for these out of the ordinary glaucoma symptoms. Encourage your patients to get yearly eye screenings and always educate them about these emergent symptoms.

References Angle- Closure Glaucoma. (2015). Retrieved January 28, 2016, from http://www.glaucoma.org/glaucoma/angle- closure-glaucoma.php Glaucoma. (2015). Retrieved February 1, 2016, from http://www.mayoclinic.org/diseases- conditions/glaucoma/basics/definition/con-20024042 Five Common Glaucoma Tests. (n.d.). Retrieved January 28, 2016, from https://hooptometrist.wordpress.com/tag/glaucoma/ Primary Angle- Closure Glaucoma. (2001). Retrieved February 1, 2016, from http://www.aoa.org/documents/optometrists/CPG-5.pdf Shah, N. N., MD, Bowd, C., PhD, Weinreb, R. N., MD, & Sample, P. A., PhD. (2006). Combining Structural and Functional Testing for Detection of Glaucoma. Opthamology. Retrieved February 1, 2016, from http://www.sciencedirect.com.ezaccess.libraries.psu.edu/science/article/pii/S0161642006008384