Glaucoma, the Silent Thief of Sight

What is glaucoma?

Glaucoma is a chronic progressive eye disease characterized by a degeneration of the optic nerve. This can lead to serious vision loss if not detected and treated early. The optic nerve takes all of the information the eye sees and transmits that information to the brain. Glaucoma is one of the leading causes of blindness in Canada.

What causes glaucoma?

The exact cause and mechanism of glaucoma is not fully understood. There seems to be some level of mechanical compression and/or decreased blood flow to the optic nerve. Although high eye pressure sometimes leads to glaucoma, many people can also develop glaucoma with “normal” eye pressure, known as normal-tension glaucoma (NTG).

An injury, infection or tumour in or around the eye can cause the pressure inside the eye to rise, leading to a form of glaucoma. These situations are referred to as secondary glaucoma, because their cause is a result of another medical condition.

Who gets glaucoma?

Glaucoma most frequently occurs in individuals over the age of 40, and there is a hereditary tendency for the development of the disease in some families. There is also a greater risk of developing glaucoma when you have diabetes, high blood pressure or a history of eye injuries. Regular eye examinations by a doctor of optometry are important for people of all ages to assess the presence of, or your risk for, glaucoma. Glaucoma cannot be detected without an eye exam.

Why is glaucoma harmful to vision?

The optic nerve, at the back of the eye, carries visual information to the brain. As the fibers that make up the optic nerve are damaged due to increased pressure and/or reduced blood flow to the nerve, the amount and quality of information sent to the brain decreases and a loss of vision occurs. Usually peripheral vision is affected first, followed by central vision during the later stages of the disease.

Will I go blind from glaucoma?

If diagnosed at an early stage, eye drops and laser treatment can control glaucoma and little or no further vision loss should occur. If left untreated, peripheral vision is affected first, followed by central vision loss during late stages of the disease. Complete blindness may occur.

How can I tell if I have glaucoma?

Primary open-angle glaucoma often develops painlessly and gradually. There are no early warning signs. It can gradually destroy your vision without you knowing it. Regular eye exams are important for people of all ages to assess the presence of, or your risk for, glaucoma. Glaucoma cannot be detected without an eye examination. Acute angle-closure glaucoma is a more sudden type of glaucoma and may have warning signs and symptoms such as nausea, eye pain, red eyes, blurred vision and haloes around lights.

How is glaucoma detected?

A comprehensive eye examination is often the only way to detect glaucoma. Your doctor of optometry will perform a simple and painless procedure called tonometry during your routine eye exam, which measures the internal pressure of your eye. Because normal-tension glaucoma causes damage to the optic nerve without eye pressure exceeding the normal rang, it is detected by observing the optic nerve for signs of damage. As part of a comprehensive exam, your doctor will take a detailed look at your optic nerve often through a dilated pupil using a series of hand held lenses. They may also use advanced imaging devices when assessing your optic nerve.

Is all glaucoma detectable?

Normal tension glaucoma is symptomless and can often take years to manifest. Diagnosis of NTG can involve monitoring a patient with standardized eye exam equipment over a number of years, and watching for changes to the optic nerve and/or visual field over time. As part of this testing, your doctor will monitor for signs and symptoms of NTG and refer for the appropriate tests or to the appropriate specialist whenever that is warranted or indicated. Some optometry offices choose to incorporate extended testing in their offices (such as Optical Coherence Tomography, which provides high-resolution, cross-sectional imaging of ocular tissues) to save referral wait times. Other offices will refer for further testing, knowing it is readily available in a colleague’s office (optometrist or ophthalmologist).

How is glaucoma treated?

Treatment of glaucoma will depend on the severity and progress of the disease. It cannot be cured, but rather controlled, often with daily eye drops. Laser surgery is also an effective way to control glaucoma and maintain your remaining vision. In more complicated cases, surgery may be needed to completely bypass the eye’s natural drainage system. Once vision is lost due to glaucoma, it cannot be restored. This is why regular preventive eye exams with one of our Doctors of Optometry are so important.

Don’t Let Your Job Be a Pain

Millions of Canadians are affected by computer eyestrain, a symptom of computer vision syndrome (CVS), according to Dr. Pavan Avinashi.

“March is Eye Safety in the Workplace Month, and as our nation has moved from a manufacturing society to an information society, computer vision syndrome has become a workplace concern,” Dr. Avinashi said. “While prolonged computer use will not damage vision, it can make you uncomfortable and decrease productivity.”

CVS is caused by the eyes constantly focusing and refocusing on the characters on a computer screen. These characters don’t have the contrast or well-defined edges like printed words and the eyes’ focus cannot remain fixed. CVS can be partially alleviated by changes in the ergonomics of the work area.

“Symptoms of CVS include headaches, loss of focus, burning or tired eyes, blurred vision, and neck or shoulder pain,” Dr. Avinashi said. “Proper lighting and monitor placement can go a long way toward reducing CVS, as can giving your eyes frequent ‘breaks’ from the computer. But the underlying cause of CVS – the ability of the eyes to focus on the computer screen – may only be remedied by specialized computer glasses.”

Dr. Avinashi said a comprehensive eye exam, including questions about a person’s computer-use habits, is the first step. If it is determined that vision correction for computer use is required, an eye doctor can prescribe computer lenses that are designed to improve your vision in the 18” to 28” range, the optimal distance between your eyes and the computer monitor.

Dr. Avinashi is the owner and practitioner of Vision Source New Westminster located at #108 - 301 East Columbia Street in New Westminster. For more information, call 604.553.3900 or visit www.visionsourcenw.com.

Our Patients' Top Five Frequently Asked Questions!

Want to know what our patients have been asking us?

Here are the top five frequently asked questions our Vision Source® members get at their practices!

FAQ #1: “How often do I need to visit the optometrist?”

For those of you who do not need glasses or contacts, we encourage you to get an eye exam every two years. If you require vision correction or are over 60, we recommend coming in on a yearly basis. Every patient is unique, however, and some patients may need to have more frequent checkups.

It’s important to remember that regular eye exams are crucial for both vision correction and your health! Prescriptions can change over the course of a year, even without you realizing it. What’s more, eye care professionals are often the first medical providers to identify chronic diseases such as diabetes, hypertension and high cholesterol. We want to help you see and feel your best, and good, healthy vision is a large part of that. So come in today!

FAQ #2: “Why can’t I sleep in my contacts?”

Those who sleep in their contacts are six to eight times more likely to get a serious type of corneal infection. Even those who use extended wear lenses have an increased risk of infection when they sleep in their contacts.

Because contact lenses rest directly on the eye, they decrease the amount of oxygen that reaches your eyes from the environment. When they are left on longer than recommended, or overnight, your eyes are deprived of much-needed oxygen, making you more prone to infection. Do your eyes a favor–give them a break at night!

FAQ #3: “What’s the difference between soft contact lenses and gas permeable (GP) lenses?”

While soft contact lenses are made of softer flexible plastics, gas permeable lenses are made of rigid plastics and can be used for up to a year or more. Gas permeable lenses may take a while to get used to but they have many advantages. No matter what you choose, we’re here to help you find the lenses that work for you and your lifestyle!

FAQ #4: “What does 20/20 vision mean?”

“20/20” is a fraction that describes visual acuity, or sharpness of vision. The top number in the fraction refers to the viewing distance between the patient and the eye chart–typically 20 feet. The bottom number in the fraction corresponds to a line on the chart. 20/20 vision isn’t “perfect” vision, but rather a measurement of what, on average, most people are able to read 20 feet away from the eye chart.

FAQ #5: “What are those cobwebs floating around in my field of vision?”

Floaters may look like tiny worms or cobwebs floating in the air in front of you, but they’re actually inside your eye! As we age, protein fibers in our eyes start clumping together. When light enters the eye, these clumped fibers cast a shadow on the retina, causing us to see floaters. Although bothersome, they’re usually no cause for concern!

Check out the video to learn more about those floaters!

We Love It When Our Patients Ask Questions!

We hope these questions and answers have been eye opening for you! The more educated you are about your eyes, the better you will feel about making decisions for your vision health. Have any more questions? Call or visit us at www.visionsourcenw.com.

Prevention Information

Good vision is about making good choices. Your best choice is to see your doctor of optometry for a routine eye exam to ensure good vision and eye health. Early diagnosis and treatment are keys to preventing vision loss. Don’t assume that red eyes, pain or unusual visual symptoms will go away on their own. You can never be sure: some eye diseases only show symptoms when the condition is advanced and difficult, or even impossible to treat.

It’s about making smart decisions at home. Everything from sitting at a distance equivalent to at least five times the width of your TV screen; eating the right foods to help deter the onset of certain eye conditions; taking a 20 second break from your computer screen every 20 minutes and focusing your eyes on something at least 20 feet away; wearing proper protective eyewear when undertaking most major indoor or outdoor work; to the simple habit of having your child wear sunglasses outside when the sun is shining. Good vision and eye health means making smart choices at work, too. At the office, being farsighted, nearsighted, or having astigmatism can all make computer use less comfortable.

Depending on your condition, your eyes could be exerting extra focusing effort or be forced to work harder to maintain a clear image on the screen. We provide expert eye health and leading prescription safety eyewear to industries as diverse as forestry and IT, offering comprehensive eye examinations, professional consultation and individually tailored programs to help employees work safely and effectively. Through comprehensive eye health services, such as visual field assessments and vision training, your doctor of optometry can detect, manage and treat conditions such as job-related eyestrain, age-related vision change and disease. Talk to one of our doctor of optometry to ensure you are making the right choices.

Rise in Detergent Eye Injuries

An increase in the number of toddlers sustaining chemical burns from laundry detergent pods has been revealed in a new study.

A 30-fold increase in ocular chemical burns from laundry detergent pods has prompted calls for closer scrutiny of the household products.

Researchers at the John Hopkins Center for Injury Research and Prevention in Baltimore found that the number of eye injuries related to laundry detergent pods among young children in the United States skyrocketed between 2012 - 2015.

Over the period, there were 1201 ocular chemical burns caused by laundry detergent pods among three and four-year-olds.

The number of eye injuries caused by the pods increased from 12 in 2012, to 480 in 2015.

The pods contain concentrated alkaline detergents, with the potential to penetrate deep into the cornea and ocular tissues and cause significant damage.

Study author, Dr Richard Sterling Haring, told OT that many of the injuries occurred when children were handling the pods and the contents squirted into one or both of their eyes.

Children were also injured when the pod contents leaked onto their hands and a burn resulted from subsequent hand-eye contact, Dr Haring added.

“In addition to proper storage and use of these devices, prevention strategies might include re-designing packaging to reduce the attractiveness of these products to young children and improving their strength and durability,” he highlighted.

Dr Haring explained that, while he did not have any data on injury levels related to laundry detergent pods in the UK, he would expect numbers to be similar depending on market penetration.

“Over the past few years, they have become quite common in American households, which I believe has been the major contributor to the upward trend of associated injuries.”

He emphasised that eye health professionals should be aware of the risk posed by laundry detergent pods.

“Toddlers are the highest-risk group for chemical ocular burns and laundry detergent pods represent an especially notable threat,” he added.

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New solutions to treat dry eye disease are progressing successfully

Dry eye specialty optometrists may soon be able to add new tools to their treatment arsenal, as

international research progresses on new therapies.

Researchers at the University of Virginia hope that a natural protein found in tears may one day offer relief to dry eye patients.

University of Virginia cell biologist, Professor Gordon Laurie, was part of the team that discovered the protein – which was named lacritin – using biochemical screening. Later studies showed that its active form, which lubricates the cornea, is frequently missing in dry eye patients.

Professor Laurie and his fellow researchers have now created an eye drop called Lacripep that replaces lacritin in the eye.

Working as part of the new spin-out company TearSolutions, Professor Laurie told OT that he will launch a four-week, early stage clinical trial for 201 patients with Sjögren’s syndrome. Patients will receive a placebo or Lacripep, in either a low or a high dose.

“This is a small step in our mission to provide…dry eye sufferers with a truly effective treatment,” Professor Laurie highlighted.

Closer to market are Seciera eye drops, a new formation using the immunosuppressant cyclosporine A enclosed in spheres of molecules at the nanometre scale.

After the medication demonstrated quick and effective action on 455 patients over 12 weeks of treatment, its owner Sun Pharma is planning to launch the eye drop in Europe, the US and Japan.

Sun Pharma managing director, Dilip Shanghvi, emphasised that: “These results are highly encouraging for millions of dry eye patients across the globe that have yet to find relief for their condition.”

Image credit: Jesse Vislisel, Brice Critser

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Retinal Migraine: Causes, Symptoms, and Treatment

A retinal migraine is one of many types of migraine. A retinal migraine is rare, and it is different from a migraine headache or a migraine with aura. Those conditions usually affect the vision in both eyes. A retinal migraine affects vision in one eye only.

Around 1 in every 200 people who get migraines will have a retinal migraine.

The condition is also sometimes called an ophthalmic migraine, visual migraine, or an ocular migraine, although symptoms for these are slightly different.

A retinal migraine can cause temporary blindness or visual problems in one eye. Retinal migraines usually last for up to 1 hour and are followed by the return of normal vision.

Causes of a retinal migraine

A retinal migraine is caused by a reduction in blood flow to the eye when blood vessels narrow suddenly. There are several reasons why this might happen.

Factors that might trigger blood vessel narrowing and retinal migraines include:

• Bending over
• Birth control pills
• Dehydration
• Excessive heat
• Exercise
• High altitude
• High blood pressure
• Low blood sugar
• Stress
• Smoking

As the blood vessels relax and blood flow returns to normal, the symptoms usually disappear and vision comes back.

Some people are more at risk of a retinal migraine than others. These people include:

• People aged 40 years and under
• Individuals with a family history of migraines
• People with another condition, such as atherosclerosis, epilepsy, lupus, and sickle cell disease

It affects women more often than men.

Symptoms

Retinal migraines involve repeated attacks of certain visual disturbances. These usually happen before the headache phase of a migraine. The visual disturbances are often collectively referred to as "aura."

Symptoms occur in one eye. The characteristics of an aura may include:

• Seeing flashing, sparkling, or twinkling lights
• A blind spot or partial loss of vision
• Temporary blindness

The aura may spread gradually over 5 minutes or more and last for 6-60 minutes. Within 60 minutes of visual symptoms, the headache phase of a retinal migraine may begin.

The headache phase of a retinal migraine has symptoms like a migraine without aura. These symptoms include a headache that lasts 4 to 72 hours on one side of the head.

The headache may be:

• Pulsing or throbbing
• Moderate to severe in pain intensity
• Made worse by activities such as walking or climbing stairs

A migraine headache may also cause:

• Nausea and vomiting
• Increased sensitivity to light
• Increased sensitivity to sound

A migraine with aura is a different condition to a retinal migraine, although some of the symptoms are similar.

Migraines with aura also cause visual disturbances such as flashes of light, blind spots, and other visual changes. However, a retinal migraine differs from a migraine with aura for two main reasons:

• The visual symptoms only occur in one eye and not both
• Complete but temporary blindness may occur in one eye only

Diagnosis

There are no diagnostic tests that detect a retinal migraine. A doctor may diagnose a retinal migraine by examining personal and family medical history, asking about symptoms, and conducting an examination.

Other possible causes for the symptoms will be ruled out before a retinal migraine is diagnosed. It is important to investigate and rule out other causes of temporary blindness.

A specialist doctor might need to ensure that the symptoms are not caused by a serious eye disease or stroke.

Some people that have visual disturbances in one eye might have hemianopia. Hemianopia is the loss of vision on the same side in both eyes. This condition often happens in stroke and traumatic brain injuries.

Treatments

The medication that a doctor prescribes to treat retinal migraines may change depending on a person's age and how frequently they have retinal migraine attacks.

Prescribed medication might include:

• Non-steroidal anti-inflammatory drugs(NSAIDs), such as aspirin or ibuprofen, to relieve pain and inflammation
• Antinausea medications to prevent nausea and vomiting
• Ergotamines to narrow blood vessels in the brain to relieve a headache
• Triptans to narrow blood vessels in the brain and reduce swelling
• Beta-blockers to relax blood vessels in the brain
• Calcium channel blockers to prevent blood vessels constricting
• Antidepressants to help prevent a migraine
• Anticonvulsants to help prevent a migraine

There is currently a lack of research into the best way to treat a retinal migraine. However, most treatments focus on pain relief for headaches and reducing exposure to potential retinal migraine triggers.

Outlook

Most people that have retinal migraines will usually experience an attack every few months. The visual disturbance phase tends to last no more than an hour, and the subsequent headache can last anywhere from a few hours to a few days.

A retinal migraine is difficult to diagnose. It is often misdiagnosed as another condition or as a common migraine. While there is no cure for the condition, it can be managed and prevented through medication and avoiding triggers.

Currently, retinal migraines are not fully understood, but research is ongoing. The investigation into migraine prevention is in progress, but, as yet, there is no proven cure.

If you are experiencing headaches, please make an appointment with one of our Doctors of Optometry here.

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