How sleep apnea affects the eye

New Orleans-Sleep apnea is a lot more common than you might think, and it’s affecting your patients’ eyes and vision in drastic ways, says Brad Sutton, OD, FAAO. Dr. Sutton shared his advice on how to manage the ocular effects of sleep apnea during a session at the American Academy of Optometry annual meeting in New Orleans.

There are three types of sleep apnea:

• Central sleep apnea, which makes up 0.4 percent of apnea sufferers

• Obstructive sleep apnea (OSA), which makes up 84 percent of sleep apnea sufferers

• Mix of both, which makes up 15 percent of sleep apnea sufferers

Obstructive sleep apnea

OSA occurs when the soft tissue of the throat collapses and occludes the airway. It happens continually throughout the sleep cycle, and the airway occlusion leads to decreased blood oxygen. The pause in breathing-called an apnea-can last anywhere from seconds to minutes. The brain then signals the body to wake up and breathe, causing the body to gasp for air.

“You don’t frequently wake up during these episodes, but you take a gasping breath to try to increase the oxygen in your blood,” says Dr. Sutton. “So, it’s a cycle that never really stops.”

OSA is most common in overweight or obese men. It occurs in approximately 24 percent of men and nine percent of women. African Americans also have a 2.5 times higher risk.

Other risk factors include:

• Age

• Smoking

• Neck circumference over 19 inches (OSA occurs in 34 percent of NFL linemen)

Some common symptoms include:

• Snoring (“People with sleep apnea almost always snore,” says Dr. Sutton, but not everyone who snores has sleep apnea.)

• Daytime sleepiness

•  Cognition problems

• Restless sleep

• Morning headaches

• Observed stop in breathing by family members

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An easy way to remember these risk factors and symptoms is the acronym “STOP BANG,” which stands for:

• Snoring

• Tired

•  Observed pause in breathing

• High blood pressure

• BMI

• Age

• Neck circumference

• Gender

“Patients aren’t really aware of what’s happening during the nighttime, but during the day, they’re sleepy, they’re tired, they don’t feel like they get restful sleep,” says Dr. Sutton.

Despite its relatively high rate of occurrence, OSA goes undiagnosed in 80 percent of the men and 90 percent of the women who suffer from the disease. High rates of undiagnosed patients may be due to the fact that the best test-a polysomnography sleep study-is both inconvenient for patients and can be very costly. Patients must stay overnight at a sleep study center and be hooked up to a number of machines to measure brain waves, eye movements, muscle activity, and oral and nasal airflow. The test can cost between $3,000 to $5,000, which may be out of reach for those with high deductibles.

Next: Treatment options for sleep apnea

Treatment options for sleep apnea

There are a number of things patients can do to help reduce OSA including losing weight, quitting smoking, avoiding alcohol and sleeping pills, and sleeping on their sides.

There are dental appliances that can move the lower jaw forward to keep the airway open. These devices are 75 percent effective in those with mild to moderate OSA, but they can make temporomandibular joint disorders (TMJ) worse, says Dr. Sutton.

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Patients can also undergo several difference procedures including a pillar procedure that inserts Dacron strips onto the soft palate to keep the airway open; maxilo-mandibular advancement; uvulopalatopharyngoplasty; and tongue reduction surgery.

One of the more commonly-known treatments is continuous positive airway pressure (CPAP) therapy, a machine and mask that provide a titrated but continuous flow of air to force the airway open. Unfortunately, these devices can be uncomfortable, noisy, difficult to take while traveling, and offer no “point of use” satisfaction, says Dr. Sutton. For those reasons, fewer than 50 percent of people stick with CPAP therapy.

An alternative therapy? Playing the didgeridoo, which strengthens the muscles in the throat to prevent nighttime collapse.

Next: Sleep apnea and the eye

Sleep apnea and the eye

Dr. Sutton says that questions regarding sleep apnea need to be a part of any eyecare provider’s intake form.

“If you don’t specifically give your patients the opportunity to respond about a sleep apnea history, they usually won’t,” he says.

OSA has a number of significant ocular side effects, including:

• Floppy eyelid syndrome (FES)

• Kerataconus 

• Non-arteritic anterior ischemic optic neuropathy (NAION)

• Glaucoma, especially normal-tension glaucoma

• Papilledema

• Idiopathic central serous chorioretinopathy (ICSC)

Fewer than five percent of those with OSA have FES, but approximately 100 percent of those with FES have OSA, says Dr. Sutton. FES is most common in overweight men. Because the eyelids are loose and rubbery, they easily evert which may cause problems during sleep if lids come in contact with the pillow. Patients with FES often experience dry, gritty, irritated eyes when they wake up but improves as the day goes on. They also may experience punctate keratitis, conjunctivitis, mucous discharge, and can get mucous fishing syndrome.

NAION is very highly associated with OSA, says Dr. Sutton, citing one study that found 12/17 NAION patients had OSA, compared to 3/17 controls.

Both open-angle glaucoma and normal-tension glaucoma are common in patients with OSA, but the prevalence varies widely among studies. Studies have found that up to 27 percent of OSA patients have open-angle glaucoma, and 43 percent have normal-tension glaucoma, although most studies have found the rates to be lower. The incidences is believed to be related to poor blood flow and decreased oxygen delivery to the optic nerve.

The association with papilledema is unclear, but it may be due to the common risk factor. The cause of ICSC in OSA patients is also unknown, but it may be due to increased epinephrine causing increased catecholamine levels.

Patients with OSA may also suffer side effects from CPAP therapy, including dry eye and irritation secondary to air leakage around the mask, bacterial conjunctivitis (also probably related to air leakage), and increased intraocular pressure (IOP) by as much as five to eight points for those who are not on glaucoma therapy.

Next: Other health problems associated with OSA

Other health problems associated with OSA

Patients with undiagnosed OSA-who make up the vast majority of those who suffer from sleep apnea-have average yearly medical costs that are $1,336 greater than those without OSA.

OSA is a common comorbidity with a number of health complications:

• 70 percent of obese individuals have OSA

• 50 percent of individuals with heart disease have OSA

• 60 percent of stroke patients have OSA

• 80 percent of patients with difficult-to-control hypertension have OSA

“If these statistics don’t drive home for you how much of a driver sleep apnea is in cardiovascular disease, they really should,” says Dr. Sutton. “It is a huge public health problem in this country.”

OSA is also commonly occurs in psychiatric populations.

Dr. Suttons says that a study followed OSA patients over 20 years and found that cancer incidence is 2.5 times higher in patients with OSA, while cancer mortality was 3.4 times higher.

“Having that constantly de-oxygenated blood most likely keeps our immune system from being able to keep those cancer cells at bay,” he says. 

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