Common Eye Disorders
Here you will find information on a variety of common eye disorders and their treatments.
Age Related Macular Degeneration (AMD)
Amblyopia (lazy eye) and strabismus (cross-eyed)
Cataracts
Diabetes and the Eye
Dry Eye Syndrome
Glaucoma
Refractive Error
Retinal Detachment
Age Related Macular Degeneration
Age-related macular degeneration (AMD) is a progressive deterioration of the macula, the small area of the retina responsible for our central vision. It usually causes a slow, painless loss of vision but in rare cases there can be a sudden vision loss. Patients may complain of fuzzy or distorted central vision affecting their ability to read, drive or see faces. There are two forms of AMD: dry and wet.
Dry Age Related Macular Degeneration
Dry AMD causes a gradual decrease in central vision as cells in the macula start to break down. This accumulation of metabolic waste in the retina results in small yellow-white deposits known as drusen. As the disease progresses from the early to intermediate stage, larger drusen may develop and this increases their risk of progressing to an advanced disease state. In advanced dry AMD, the damage to retinal tissue can lead to areas of atrophy and vision loss.
Wet Age Related Macular Degeneration
Wet AMD is the more severe form of the disease and causes a rapid, dramatic loss of central vision due to the growth of abnormal blood vessels below the retinal tissue that can break and leak blood into the macula.
Non-controllable Risk Factors
- Age: As we age the risk of developing AMD increases
- Family history: You have a higher risk of developing AMD if someone else in your family has also been diagnosed with the disease.
- Ethnicity: Caucasians are most likely to develop AMD.
Controllable Risk Factors
- Smoking: Both smokers and those who live with them are at a greater risk for developing AMD.
- Healthy Diet and Healthy Weight: A healthy diet rich in dark, leafy green vegetables, anti-oxidants (including omega-3 fatty acids) and low in carbohydrates and processed packaged foods can help in the prevent AMD. Exercising and controlling your weight and blood pressure can also help decrease your risk. Vitamin supplements may also be recommended for the treatment or prevention of AMD.
- Protecting your eyes from UV rays by using sunglasses and wide-brimmed hats can also reduce your risk.
Treatment
There are currently no known treatments for dry AMD. We can educate patients on modifying their controllable risk factors and may introduce vitamin or supplement therapy to help lower their risk of progressing from intermediate to advanced AMD. New evidence suggests that we may be able to target these supplements based on a patient’s genetic profile.
Treatments for wet AMD are designed to minimize and possibly restore vision loss. Most commonly this includes the injection of medications into the eye that act to prevent the growth of abnormal blood vessels in the retinal tissue. Older treatment options included using a laser to target abnormal vessels either directly or with the use of a dye that when exposed to the laser is activated and blocks the leakage of blood from the vessels. These treatments are rarely used today.
Amblyopia (Lazy Eye) and Strabismus (Cross Eyed)
When the visual acuity (what that an eye can see) is less than that of the other eye, this is amblyopia. When an eye is turned in or out, this is known as a strabismus. These can occur independently or together.
Amblyopia
In order for normal vision to develop, both eyes must send a clear image to the brain. If one eye presents a blurry image, the brain will start to favour the image from the good eye and will ignore or suppress the image coming from the bad eye, resulting in vision loss known as amblyopia. This neural inhibition is an active process and, if it is not corrected, can lead to permanent vision loss that cannot be corrected with glasses, contact lenses or laser surgery. It is most often seen in one eye although, occasionally, it can affect both eyes. The main causes of amblyopia are:
- a large difference between the refractive error of the two eyes, known as anisometropia
- constant strabismus (eye is turned 100% of the time in a particular direction—in, out, up or down)
- an occlusion that is preventing or reducing the amount of light that can enter the eye due to a physical blockage (e.g., congenital or traumatic cataract, trauma to the extraocular muscles or ptosis [droopy eyelid])
Strabismus
Strabismus can be due to an ocular muscle imbalance in the extraocular muscles (responsible for proper eye alignment) or due to trauma or high refractive error.
A strabismus can be constant or intermittent. If a strabismus occurs intermittently, it means there are times when the affected eye is sending a clear image to the brain. In that event, the eye is less likely to suffer permanent vision loss.
Treatment
The treatment of amblyopia and strabismus can include a variety of options.
| Eyeglasses or Contact Lenses | In some cases, this is all that may be required. |
| Prism Lenses | These change the direction of light entering the eye, helping to reduce the amount the eye has to turn. |
| Patching | This can include full or partial occlusion patching of the good eye to “force” the bad eye to focus (in our clinic we use a patch that does not fully block the stronger eye because this is more comfortable for our patients and yields better results than full occlusion). |
| Eye Drops | These can be used as an alternative to patching in non-compliant patients. |
| Vision Therapy | Vision therapy is a combination of in-home and in-clinic activities that teach the eyes and the brain to work together more effectively (in cases where we believe that vision therapy is the best option, we will refer the patient to one of the vision therapy clinics in Ottawa). |
| Eye Muscle Surgery | Surgery can change the position or the length of the extraocular muscles to eliminate the eye turn so the eye appears straight. These patients often require vision therapy to help prevent the eye turn from developing again. In some cases, multiple surgeries are required. |
Cataracts
Cataracts are the development of opacities in the lens of the eye. They usually occur with aging, although some varieties are commonly associated with different systemic diseases or as a result of ocular trauma. Normally when light enters the eye it passes unobstructed through the cornea and the lens towards the back of the eye where it lands on the retina. In a patient with a cataract, the opacities cause the light entering the eye to scatter before it reaches the retina, which can lead to many different visual issues. These can include blurry or distorted vision, changes in the vibrancy of colours, and often increased problems with glare, especially when driving at night.
With a comprehensive eye exam, we can examine the lens and detect cataracts and monitor them for changes. When it gets to the point that a cataract is affecting the patient’s vision or we are concerned that it will soon prevent them from accomplishing their daily activities, we will refer the patient to an eye surgeon. We have relationships with many cataract surgeons in the Ottawa area, and will co-manage treatment both before and after surgery.
Diabetes and the Eye
Diabetes is a chronic disease that leads to increased levels of sugar in your bloodstream due to the inability of your body to either make or use insulin. The effects of diabetes on the eye can vary and include changes in refractive error which can lead to fluctuating blurry vision and new floaters or shadows in your field of view. Diabetes can also lead to the development of cataracts, glaucoma, swelling or bleeding within the retina. It can also paralyze the nerves that control the opening and closing of the pupil or the nerves that control the sensitivity of the cornea, causing slow wound healing.
Diabetes can affect the small blood vessels throughout the body; when it affects small vessels in the eye, diabetic retinopathy can occur. In non-proliferative (early stage) diabetic retinopathy, these vessels can swell and leak, causing bleeding and swelling of the retinal tissue, or the vessels can close and prevent blood from travelling through them. In either case, this may result in less blood reaching the retinal tissues. This leads to the abnormal growth of new blood vessels on the retina or other structures within the eye, which is known as proliferative diabetic retinopathy. New vessel growth must be treated quickly because, untreated, it may lead to blindness.
Monitoring is Key
Patients diagnosed with diabetes are eligible for an annual eye exam through OHIP. It is important to keep up with regular appointments to ensure that any changes are noted quickly and can be monitored. With early detection, treatment is more likely to have a positive outcome.
In our clinic, we use both direct observation (though a dilated pupil) and retinal imaging to monitor the health of our patient’s eyes. Should any changes be detected, we may begin by monitoring the patient more often, or we may refer them to an appropriate specialist. Treatment can include injections with compounds that work to prevent the growth of abnormal blood vessels, or laser therapy aimed at sealing leaking blood vessels.
To prevent diabetes-related eye problems, it is important to work with your doctor to monitor and control your diabetes. Uncontrolled blood sugar levels and long-term diabetes are the biggest risk factors for developing diabetic retinopathy. Other risk factors include high blood pressure, smoking, drinking and pregnancy.
Dry Eye Syndrome
A normal eye has a tear film, a coating that is made up of three layers: an outer oily layer, a watery layer and an inner mucus layer. The components of these layers are made in glands in the eyelids and they all work together to protect and nourish the front surface of the eye.
When eyes feel irritated, gritty or dry, this can be caused by a lack of tear production or tears that are not made up of their normal components. Alternatively, the tears may be evaporating too quickly, leaving the eyes feeling uncomfortable and dry. If left untreated, dry eye can make it difficult to wear contacts and, in extreme cases, lead to tissue damage and scarring, which can impair vision.
Making a Diagnosis
To diagnose the factors contributing to a case of dry eyes, we will inquire about the patient’s health, the medications they are taking and their home and work environments, as all of these can have an effect on the severity of symptoms that patients are experiencing.
Symptoms can include tearing, burning, stinging, gritty or scratchy eyes. Patients may find their vision fluctuates throughout the day, or only while performing certain tasks.
Surprisingly, one of the main symptoms of dry eyes is actually tearing. When the eyes are dry and irritated, they will over-produce watery tears to try and make the eyes more comfortable, but this leads to an overabundance of the watery tear layer. Without adequate oily and mucus layer components, the excess watery tears cannot be held against the eye, resulting in watery, runny eyes.
To determine the best course of treatment, we may perform a number of specific tests to measure the volume and quality of the tears.
Treatments can include using artificial tears, gels or ointments to supplement the tear film on the eyes. In some cases, tiny silicone or gel-like plugs can be used to block the tear ducts, preventing tears from draining too quickly from the eyes.
When tear production is too low, omega-3 supplements and manual manipulation of the lids may be required to help increase the amount of tears and improve the ability of the eyelids to release tears onto the eye. Prescription medication is sometimes necessary to improve the quality and amount of tears being produced. Additionally, warm compresses and manual cleaning and care of the eyelids and lashes may be needed to help control inflammation on the surface of the eye. This can be done at home with wipes or, in severe cases, in-clinic treatments may be required.
The goal of treatment is to restore or maintain the normal amount of tears in the eye so as to minimize discomfort. Unfortunately, dry eye syndrome is usually a chronic condition that cannot be cured and, although the type and frequency of treatment can change as the condition becomes better managed, it does require ongoing actions on the part of the patient and regular eye care appointments.
Glaucoma
Glaucoma is a group of eye diseases that leads to progressive degeneration of the optic nerve. Together, these diseases are the second most common cause of vision loss in Canada. Over time, damage to the optic nerve tissue leads to gradual irreversible vision loss and can, if left untreated, result in blindness. Risk factors for glaucoma include elevated ocular pressure, family history, age, ethnicity, nearsightedness, high blood pressure and diabetes.
Primary Glaucoma
Open-angle glaucoma is the most common form of glaucoma in Canada, affecting more than 250,000 Canadians. Increased ocular pressure, either due to an over-production of fluid within the eye, or due to the inefficient drainage of that fluid from the eye, can lead to damage of the optic nerve head. This process initially occurs without symptoms; there is no pain and vision remains the same. Without treatment, as the damage to the optic nerve tissue increases, the patient will slowly lose their peripheral vision, making it seem like they are looking through a tunnel.
If left untreated, central vision may also become affected, leaving the person with no functional vision. Treatment of primary open-angle glaucoma focuses on lowering the intraocular pressure using medications as well as laser procedures and other surgeries, all with the goal of improving the efficiency with which fluid can be removed from the eye.
Closed-Angle Glaucoma
In this type of glaucoma, the fluid within the eye is unable to drain and pressure within the eye quickly becomes elevated. This causes severe pain, nausea, a red eye and blurry vision. This is a medical emergency and anyone who presents with these symptoms is referred to a specialist for immediate laser surgery and the administration of medication to lower the pressure within the eye.
Secondary Glaucoma
With secondary glaucoma, damage to the optic nerve can be attributed to many different conditions, including a physical blockage of the drainage system in the eye caused by pigment or other materials, a history of eye injury or inflammation, complications from a previous ocular surgery, certain medications, high blood pressure or diabetes. Treatment will vary depending on the cause but, as with other forms of glaucoma, may include medications or laser or other surgery to lower ocular pressure.
Normal Tension Glaucoma
This type of glaucoma results in damage to the optic nerve head despite normal eye pressure. This form of the disease is not well understood (one risk factor may be low blood pressure), but treatment is still focused on decreasing intraocular pressure.
Refractive Error
Blurry vision is one of the most common reasons our patients come to see us, and it is usually due to refractive error. When light travels through different materials in the eye, it is bent (refracted) at different angles and with specific powers so that it comes to a point on the retina, allowing us to see a clear image. When we are able to use the lens in our eye to change how light is bent, it enables us to focus on objects at different distances. Refractive error occurs when the shape of the eye changes either the focusing power of the eye or the angle of light as it enters through the pupil, preventing the light from focusing on the retina. Changes—in the length of the eyeball, the surface of the cornea or the lens of the eye—can cause problems with the refraction of the light rays entering the eye. Treatment for refractive errors can includes glasses, contact lenses or refractive surgery.
Myopia (Nearsightedness)
When the focusing power of the eye is too strong, the light entering the eye will focus in front of the retina. These patients have trouble seeing things in the distance clearly and will usually complain about difficulty seeing road signs or the chalkboard at school, or will say they are squinting a lot.
With more and more people being diagnosed with myopia, there is a lot of interest in trying to find ways to manage the progression to higher prescriptions. In our clinic, we can use a combination of soft multifocal contact lenses and low-dose atropine eye drops in an effort to slow the progression.
Hyperopia (Farsighted)
When the focusing power of the eye is not strong enough, the light entering the eye will focus behind the retina. Patients experience hyperopia differently; many may not have trouble seeing objects at any distance, especially when they are young. Others may see objects in the distance clearly, but have trouble seeing objects and print close up. Still others with a higher level of hyperopia will have blurry vision at all distances.
Astigmatism
When the shape of the eye is more oval or football shaped versus its normal spherical or baseball shape, it causes light rays entering the eye to focus in multiple places instead of on one focal point on the retina. These focal points can fall onto, in front of, or behind the retina. This causes complaints of blurry, stretched-out vision or images with shadowing.
Presbyopia
As we age, it becomes difficult to see objects or images up close because the lens in the eye loses its ability to change its shape and can no longer focus at those near distances.
Retinal Detachment
Description and Treatment
The retina is a light-sensitive tissue that lines the inside of the eyeball. It is responsible for capturing the information that is then interpreted as the images that we see. During a retinal detachment, the retinal cells become separated from their underlying tissues and cannot receive nutrients from their blood supply. When this happens, it is a medical emergency and needs to be treated immediately to prevent cell death and permanent vision loss. Depending on the severity of the detachment, there are different treatment options. These include laser “spot welding” to tack down the retina, injecting a gas bubble into the eye to keep the retinal tissue in place, and intraocular surgery. In the event of a retinal detachment, our office can refer you to the appropriate clinic or hospital for treatment, as required.
Signs and Symptoms
- Sudden appearance of “floaters” and flashes in both or one eye
- Reduced vision in the area of the detachment (may look like a blurry area in your field of vision)
- A curtain-like shadow or an area of vision that looks like wallpaper falling down in your visual field
Who’s at Risk?
The risk of retinal detachment increases for those who
- have previously had a detachment
- have a family history of detachments
- are extremely nearsighted
- are over age 50
- have undergone eye surgery (including cataract removal or laser correction)
- have had, or currently have, an eye disease or inflammation
- have suffered an eye injury or head trauma (in some cases, the detachment can occur years later)
