By Dr. Douglas J. Ryen, Pickerington Eyecare
Glaucoma is the leading cause of preventable blindness. Over three million people in the United States have glaucoma, and this number is projected to be nearly 60% higher by 2030. People who develop glaucoma can lose nearly half of their peripheral vision without noticing. It cannot be prevented, but if diagnosed and treated at an early stage it can usually be well controlled. Glaucoma is one of the main reasons to have regular eye examinations to preserve vision.
What is glaucoma?
Glaucoma is an eye disorder that leads to damage of the optic nerve, resulting in peripheral vision loss and blindness if left untreated. The exact cause of glaucoma is unknown. It is usually associated with increased intraocular pressure, but some types may be due to lack of adequate blood supply to the optic nerve. Glaucoma is most commonly diagnosed after age 40, but can affect people of all ages.
Types of glaucoma
Primary Open Angle Glaucoma is the most common form. Signs include high intraocular pressure which leads to damage of the optic nerve and eventually blindness if left untreated.
Angle-closure glaucoma is a less common form. It is a true medical emergency that can cause almost immediate vision loss. The anatomical angle inside the eye where the cornea and iris meet is where the aqueous fluid drains out of the eye into the vasculature. In some people this angle becomes narrow which reduces the drainage of the fluid, causing increased pressure. This type of glaucoma may cause acute symptoms of pain, blurred vision, and redness.
Normal tension glaucoma is often the most difficult to diagnose. This occurs when the optic nerve is damaged even though the intraocular pressure is normal. Vision loss is most likely caused by reduced blood supply to optic nerve.
Glaucoma worsens over time. Change in the optic nerve, possibly a change in intraocular pressures, loss of nerve tissue, and corresponding loss of vision confirm the diagnosis.
People at higher risk of developing glaucoma include:
. Those of African, Asian, or Hispanic descent
. Middle age to elderly
. Those with a family history of glaucoma
. People with medical conditions like diabetes, hypertension, heart disease
. Thin corneas
. Chronic eye inflammation
. Medications that increase the pressure in the eyes, e.g. corticosteroids
How is glaucoma diagnosed?
Early detection is vital to slow or halt the progression of glaucoma. Glaucoma is diagnosed by a comprehensive eye exam only. A comprehensive eye exam will include:
. Tonometry – to measure the pressure inside the eye. For example, the “air puff test” or our new iCare pressure test that does not use air
. Pachymetry – to measure corneal thickness
. Visual field testing – measures peripheral and central vision. New automated technology (such as ours) measure the sensitivity of the visual field and can compare to normative data.
. Retina evaluation – dilated exam or our Optomap retinal exam, which can get a view of the entire retina sometimes without dilating the pupil. This newer technology has been seen on shows such as “Dr. Oz.”
. Supplemental testing – may include testing such as gonioscopy, OCT, and VEP, all of which we use in our practice.
Glaucoma worsens over time, so change in optic nerve, possibly a change in intraocular pressures, loss of nerve tissue, and corresponding loss of vision confirm the diagnosis.
How is glaucoma treated?
There is no cure for glaucoma, but it can be managed with medication and/or surgery to prevent vision loss.
The goal of treatment of glaucoma is reduction of the intraocular pressure. The most common initial treatment is medicated eyedrops used daily. There are several types of glaucoma medications. Some patients may need a combination of two or more different eyedrops. Some types of glaucoma may require laser treatment or conventional surgery.
Acute angle-closure glaucoma is different, as it is a medical emergency. Several medications are used immediately to reduce the intraocular pressure, then followed by a laser treatment called peripheral iridotomy to further control pressure.
Patients must maintain treatment for a lifetime. Treatment may need to be periodically adjusted, so regular examinations – usually multiple times per year – are often necessary.
Regular eye exams are important!
The only way to determine whether or not you have glaucoma is to get a comprehensive eye examination. If you do not have an eye doctor, we are happy to accept new patients.
We typically recommend a yearly eye exam for most of our patients. Our practice has a pediatric optometrist on staff who enjoys seeing children as young as six months old. She participates in a program called InfantSEE (www.infantsee.org); children aged 6-12 months old are seen at no charge. The next eye exam is typically at age 3, then age 5, then yearly for most patients.
Early detection, prompt treatment, and regular monitoring are essential to control glaucoma and reduce the chances of vision loss.
For more information, please refer to our website www.pickeringtoneyecare.com or feel free to email me directly at firstname.lastname@example.org.