You have almost certainly heard of diabetes, which is one of the most common chronic health conditions in the United States with an estimated 100 million adults currently living with diabetes or pre-diabetes. This metabolic disorder occurs when the body is no longer able to regulate its own blood sugar levels and requires intervention to keep them stable. Most people are aware that diabetes can have serious consequences for our health. However, you may be surprised to learn that it can also influence our vision. This is because patients who are diabetic can go on to develop a complication that is known as diabetic retinopathy. Without prompt treatment, diabetic retinopathy can cause permanent vision loss. It is for this reason that patients who suffer from diabetes are asked to attend regular diabetic-related eye exams.
For us to be able to see clearly, our eyes need to be healthy and functioning perfectly. The most important component of our eyes are the retina. Found at the very back of the eye, the retina is a patch of light-sensitive cells that have the job of converting the light that passes into the eye into messages that are passed up the optic nerve and into our brain. Our brain then receives them and tells us what we can see and how clearly we can see it.
The retina relies on a continuous supply of blood, which is delivered using a network of tiny blood vessels. Over time, having continuously high blood vessels can damage these blood vessels causing a leak of blood and other fluids onto the retina. If this happens, scarring may occur which could compromise the quality of your vision.
Technically, anyone who suffers from diabetes, whether it be Type 1 or Type 2, could be at risk of developing diabetic retinopathy. However, the condition is more likely in certain situations. These include if:
your blood sugar levels are uncontrolled or poorly controlled
you have a long history of diabetes
you have high blood pressure (hypertension)
you suffer from high cholesterol
you are pregnant
Regular diabetic-related eye exams will enable your eye doctor to monitor your condition and ensure that any signs of diabetic retinopathy are detected and acted upon immediately.
The process of a diabetic eye exam is very simple and straightforward. In fact, in most instances, it is included within the other elements of comprehensive eye exam and you may not even realize that you have had a specific test to check for diabetes-related complications.
Diabetic eye screening is non-invasive. You will be given eyedrops which will blur your vision. These may sting a little when they are administered, but this will pass within just a few moments. Once your vision is blurred, you will be asked to rest your head onto a device and stare down a lens. This leads to a camera which will take images of the backs of your eyes so that your eye doctor can assess the structures, which include the retina, for any abnormalities. You will see a flash when each image is taken, but at no point should you be in any pain.
In addition to the images of the back of your eye being taken, you will also be given a visual acuity test. This is where you will be asked to read letters off a chart a short distance away, as well as reading from a card held in front of you.
The information that your eye doctor will obtain from your examination will be able to tell them if you are experiencing any of the signs of diabetic retinopathy. If so, they will discuss the best way to get your condition under control. This could involve a combination of elements, including controlling your diabetes more effectively, taking medications or more invasive treatment to preserve your vision. Your eye doctor will give you more specific information based on your individual circumstances.
If you have further questions about diabetic-related eye exams, please contact our knowledgeable eye care team.
You might be surprised at how many tests eye doctors use to diagnose glaucoma. A proper diagnosis requires careful evaluation of many aspects of your eye’s health – from eye pressure to cornea thickness to the health of your optic nerve. This article describes how your eye doctor assesses your risk and all the tests needed to properly diagnose glaucoma.
Your eye doctor will begin by assessing your risk level for developing glaucoma. This will help determine the frequency and extent of testing needed. Through a family history and medical questionnaire, the eye doctor is looking for the following risk factors:
Over the age of 60
Ethnic background such as African or black Caribbean descent, Hispanic, or Asian
Family history of glaucoma, such as a sibling or parent with glaucoma
History of eye conditions, injuries or surgeries
Prolonged corticosteroid use (eye drops, pills, inhalers or creams)
Chronic conditions that affect blood flow, such as migraines, diabetes, low blood
pressure or hypertension
Current or former smoker
If you’ve already had a comprehensive eye exam, your eye doctor will also consider these risk factors:
Eye pressure higher than normal (above 21 mm Hg)
Thin corneas (less than 0.5 millimeters)
Your type of eyesight is also important. People with farsightedness are at a higher risk for narrow-angle glaucoma, a more serious type that can advance quickly. While nearsightedness is associated with open-angle glaucoma, which progresses slowly without any symptoms.
During a comprehensive eye exam, your eye doctor will always check for glaucoma, regardless of the risk level. This provides a baseline for comparison as you age. There are two tests: tonometry and ophthalmoscopy.
Tonometry measures the pressure within your eye. Your eye doctor will give you drops to numb your eyes. Then he/she will use a device called a tonometer, which applies a small amount of pressure with a warm puff of air.
Eye pressure is unique to each person, so it’s not always a reliable indicator for glaucoma. It’s simply another piece of information to help your eye doctor assess your eyes. The range for normal pressure is 12-22 mm Hg (“mm Hg” in millimeters of mercury, a scale for recording eye pressure). Most glaucoma cases are diagnosed with pressure over 20mm Hg. However, some people can have glaucoma at pressures between 12 -22mm Hg.
This is an examination of your optic nerve. Your eye doctor will use eye drops to dilate the pupil, which makes it possible to see through your eye to examine the shape and color of the optic nerve. Then, using a small device with a light on the end, your optic nerve is magnified. Based on the results of these tests, your doctor may ask you to have more glaucoma exams.
Perimetry is a visual field test. It creates a map of your complete field of vision. During this test, you’ll look straight ahead and then indicate when a moving light passes your peripheral (or side) vision. Try to relax and respond as accurately as possible. To ensure accuracy, your doctor may repeat the test to see if the results are the same the next time. If you’ve been diagnosed with glaucoma, a visual field test is usually recommended at least once per year to assess changes to your vision.
This diagnostic exam helps determine the angle of your iris and cornea. First, you’ll receive eye drops to numb the eye. A hand-held contact lens is gently placed on the eye. A mirror on the contact lens shows the doctor if the angle is closed and blocked (a possible sign of angle-closure or acute glaucoma) or wide and open (a possible sign of open-angle, chronic glaucoma).
Last, your eye doctor may want to use pachymetry as another way to confirm a diagnosis. Pachymetry measures the thickness of your cornea, the clear window at the front of the eye. A probe called a pachymeter is gently placed on your cornea to measure its thickness. Pachymetry can help clarify your diagnosis because corneal thickness has the potential to influence eye pressure readings.
Glaucoma diagnosis is not as simple as you might expect. Be sure to have regular eye exams, especially if you have any of the risk factors, to detect glaucoma early.
Macular degeneration, commonly referred to as age-related macular degeneration (AMD), is the single largest cause of sight loss in the developed world and affects more than 10 million Americans. It usually affects people over the age of 60, but has been known to affect those who are younger. It is a painless condition that usually affects both eyes with the loss being experienced in the central vision. It does not affect the peripheral vision, meaning that it does not cause total blindness.
The macula is the most sensitive part of the retina and is responsible for our central vision and what allows us to see fine details with clarity.
Wet AMD is one variety of the condition in which abnormal blood vessels grow into the macula, leaking blood or fluid which then causes scarring and a rapid loss of central vision. Wet AMD can develop suddenly and rapid referral to a specialist is essential as it can be treated if caught quickly.
Dry AMD is the most common variety of age-related macular degeneration and is a gradual deterioration of the retina as the cells die off over time and are not regenerated. Up to 15% of people with dry AMD go on to develop wet AMD, and so any sudden changes in your vision should be followed up with your optometrist as soon as possible.
Macular degeneration affects each person differently, which means that it can sometimes be difficult to diagnose, particularly as you may not notice any change in your vision early on in the condition. However, as the cells deteriorate, you will start to see an increasing range of symptoms, including:
Distortion or bends in what should be straight lines (such as lampposts or door frames)
Dark spots in your central vision
Difficulty adapting from dark to light environments
Objects may appear to change shape, size or color, or may move or disappear
Bright lights may be difficult to tolerate
Words may disappear while you are reading
Unfortunately, there is no clear reason as to what triggers the process that causes macular degeneration. However, you are at an increased risk if you have a family history of the condition, or if you are over 60.
Experts suggest that the best thing you can do to minimize any potential risk is to ensure that you live a healthy, active lifestyle. You can do this by:
Eating a healthy, balanced diet with plenty of fruit and vegetables
Moderating your alcohol consumption
Maintaining a healthy weight
Getting regular exercise
There is also some limited research that suggests that eating leafy, green vegetables can slow the deterioration of vision in cases of dry AMD.
Sadly, there is currently no cure for either variety of AMD. In the case of dry AMD, the treatments suggested are done so with the aim of aiding the patient to make the most of their remaining vision. This can include things such as using magnifying glasses to help with reading.
Wet AMD can be treated with anti-vascular endothelial growth factor medication. This should stop additional blood vessels from developing and stop your vision from deteriorating further.
Occasionally, laser therapy is suggested as a possible treatment for destroying abnormal blood cells, but this is only suitable for cases of wet AMD and usually only around 1 in 7 sufferers may be potential candidates for this procedure.
If you have any questions or concerns regarding macular degeneration, we highly recommend that you speak with your optometrist who will be happy to assist you.