Get screened at one of our two locations listed below. Walk in or make an appointment by emailing MAPS@USC.EDU.
| USC Healthcare Center 2 (HC2) | USC Roski Eye Institute |
| Floor 1 Lobby 1520 San Pablo Street Los Angeles, CA 90033 9 AM – 3 PM M, W, Th, F | Floor 4 Lobby 625 S Fair Oaks Ave, Suite 400 Pasadena, CA 91105 9 AM – 3 PM M-F |
What is the Multiracial Angle-Closure Progression Study (MAPS)?
MAPS is a study led by USC Roski Eye Institute, a part of the University of Southern California’s Keck School of Medicine with funding provided by the National Institute of Health. The purpose of this study is to adapt imaging technology to increase the accuracy and frequency of glaucoma risk factor testing. Participants will be from a large, diverse racial population in order to determine why some racial groups are at higher risk of blindness and have a lower likelihood of glaucoma detection.
Eligibility and Participation
To be eligible for the study, you must be between the ages of 50 and 80, inclusively, and you must have no prior history of ocular surgery. If you are eligible, participation involves a short survey screening with a few eye imaging devices. A photo of the front of the eye will be taken to evaluate your angle width, which is a primary risk factor for angle-closure glaucoma.
Reasons to Get Screened
Glaucoma is the most common cause of irreversible vision loss, and it develops slowly and oftentimes is not noticeable until later stages. Getting screened for glaucoma can determine if you are at risk, and effective treatments can prevent vision loss from glaucoma.
What is Angle-Closure Glaucoma?
Angle-closure glaucoma occurs when fluid builds up in the eye causing increased eye pressure. Fluid builds up in the eye when the angle between the iris and cornea becomes too narrow. This blocks the drainage system of the eye and causes increased intraocular pressure (IOP). IOP can cause damage to the optic nerve that leads to irreversible blindness.
FAQs
1. How is MAPS improving the detection of people at risk for primary angle closure glaucoma (PACG)?
The current method to detect people at risk for angle closure glaucoma is called gonioscopy. Gonioscopy uses a contact lens to visualize anatomical structures of the eye. Gonioscopy requires contact with the eye and must be performed by an experienced clinician, which can be time consuming and uncomfortable for some patients. Current reliance on gonioscopy contributes to preventable cases of angle closure glaucoma being missed and people losing their vision.
In MAPS, we will be using OCT, a non-contact imaging technology that can take hundreds of images in mere seconds. We will be performing an analysis of the measurements from these images to determine if you may be at risk of developing PACG.
The ability to screen patients precisely and comfortably could help reduce the occurrence of glaucoma. Glaucoma does not yet have a cure, so it is vital to detect and treat high risk patients early, as permanent vision loss can often be prevented.
2. What is OCT technology?
Optical Coherence Tomography (OCT) is a common imaging technique used to image the eye. OCT imaging uses light rays to create 3D images in a safe and noninvasive fashion.
3. What is a fundus camera?
A fundus camera is a special camera used to take pictures of structures in the back portion of the eye, including the retina, optic nerve, macula, blood vessels, and choroid. The camera is attached to a low-power microscope that takes pictures through the pupil.
4. What is an anterior segment camera?
An anterior segment camera is a special camera used to take pictures of structures in the front portion of your eye, including the cornea, iris, and lens.
5. What is the multiracial component of MAPS and why is it so important?
Racial minority groups are disproportionately affected by PACG and related blindness in the United States. Research has shown that Black, Hispanic, and Asian Americans are at significantly higher risk of developing PACG compared to Caucasian Americans. Our recent study found that Black and Hispanic Americans with angle closure glaucoma have 50% and 3-% higher risk of blindness, respectively, compared to Caucasian Americans. Another study by our lab found that Black Americans are 30% less likely to be detected with narrow angles prior to developing PACG.
There is a glaring lack of knowledge about why some people are at higher risk of blindness and lower likelihood of detection. We will therefore be recruiting a large, diverse study cohort to determine if eye anatomy explains these racial differences in PACG risk and can help identify high-risk individuals.
6. What is the difference between primary angle closure glaucoma (PACG) and open angle glaucoma (POAG)?
PACG, results when the angle between the cornea and the iris becomes too narrow, and blocks the drainage of fluid in the eye. This buildup of fluid causes the intraocular pressure in the eye to rise, which can lead to development of glaucoma. In some cases of POAG, the angle appears open, yet the intraocular pressure is still high. In other cases of POAG, intraocular pressure is normal or even low, yet glaucoma still develops. The progression of PACG tends to be faster than POAG, due to higher intraocular pressure.
7. What is the specific risk factor we are using to determine if you are at risk of glaucoma?
We are measuring angle opening distance or AOD. This is a measurement of the distance between the trabecular meshwork (drain of the eye) and iris. If the AOD measurement is less than 0.15 mm, we consider you to have “narrow angles” and believe you may be at higher risk of PACG. If the AOD measurement is greater than 0.15 mm, you are likely at low risk of PACG.
8. Why is it so important to get screened early for glaucoma?
It is important to get screened early for glaucoma as the progression of the disease is often slow and unnoticeable to the patient. In addition, vision loss associated with glaucoma is irreversible. Therefore, early detection and treatment of glaucoma is crucial. Above the age of 50, it is important to get regular eye exams to make sure your eyes are healthy. If any risk factors of glaucoma are detected, it is important to receive a glaucoma evaluation by an eye care provider. If glaucoma is diagnosed, it is important to initiate treatment to prevent the development onset or worsening of vision loss.
9. How are these tests going to affect my vision?
They won’t! The tests you received or will receive are non-invasive, and we will not be using any sort of eye drops that will make your vision blurry. At most, there may be a bright flash when images are taken or your eyes might feel a bit dry after the images are taken.
10. What are the potential benefits of participating?
The benefits of participating are that you will receive free glaucoma risk factor screening and a $5 gift card! You will also have contributed to our effort to rid the world of glaucoma-related vision loss. Please remember that we only screened you for a specific glaucoma risk factor. Therefore, screening negative does not mean that you do not have glaucoma or should not continue to receive routine eye exams.