Glaucoma is More Than Tunnel Vision

Taking a quick glance through Google images reveals quite a few depictions of what vision is like with glaucoma. Usually a couple of kids or scenery is shown in the middle with darkness surrounding it, otherwise known as “tunnel vision.” While this may be jarring for some, it’s not entirely accurate until an individual reaches end stage glaucoma. What’s more frightening to me is that vision “loss” for the vast majority of glaucoma is just subtle peripheral blur well before dimming or darkness manifests. In fact, it’s so subtle that you would never notice it in everyday life. Coupled with the fact that glaucoma is often an asymmetric disease (one eye is more affected than the other) means that the better eye covers for the worse eye. In the example below, the children running onto the street are missing from view but the blurring of the red car is probably more accurate. As a direct result, reaction time will be slower.

The prevalence of the more common type of glaucoma (open angle) is 1.00-5.83% in adults older than 40 years of age.¹ Of these, 20-39%² don’t even have high eye pressure. So the air puff or blue light test for eye pressure is just one piece of the puzzle when diagnosing glaucoma. We definitely wouldn’t want to over or under worry any patients by the eye pressure test alone. Significant risk factors are older age, African or Hispanic heritage, nearsightedness, diabetes, migraines, poor blood circulation.4

Glaucoma is usually a slowly progressive condition so your eye doctor may monitor you in the early stages. If you have a lot of risk factors or the nerve tissue of the eye is deteriorating at a faster than average rate, treatment may be initiated. Oftentimes the first treatment chosen is a nightly eye drop. However, a very safe and painless laser procedure called selective laser trabeculoplasty (SLT) is becoming more common as the first treatment. Be sure to also tell your doctor of any eye dryness or irritation with or without the glaucoma eye drop medications.

A far less common type of glaucoma, called narrow angle glaucoma, does have acute symptoms. If your eye is ever painful, red, and you experience headaches, halos around lights, nausea, and even vomiting, don’t go to the emergency room unless that is your only option. Please seek the care of an eye doctor so it doesn’t accidentally get misdiagnosed as an infection or abrasion. It is critical to bring down the eye pressure as quickly as possible to minimize the risk of vision loss. Individuals who are farsighted have an increased risk of this type of glaucoma.

So while there is no cure for glaucoma, just like in diabetes, detecting it early can most of the time ensure your vision and quality of life is unaffected for the rest of your life. Innovative companies continue to develop new treatments for glaucoma and we now understand more of why glaucoma happens. Remember that glaucoma is called the “silent thief of sight” so please see your eye doctor annually.
glaucoma

Pictures from innovativeeyecare.com.au3

~Justin Kwan, OD
California Optometric Association
www.eyehelp.org
www.coavision.org


References
1. Nolan W, Yip J. Prevalence and Geographical Variations. Glaucoma, 1, 1-10. Second Edition.
2. Tanna AP. Normal-Tension Glaucoma. Glaucoma, 33, 378-386. Second Edition.
3. http://innovativeeyecare.com.au/what-we-do/glaucoma
4. https://www.aao.org/eye-health/diseases/glaucoma-risk

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