Vision Conditions

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Aug 27, 2008 5:20 PM

Allergic Conjunctivitis

One of the most commonly seen complications of contact lens wear is allergic conjunctivitis or Giant Papillary Conjunctivitis (GPC). This usually develops from wearing contact lenses longer than their prescribed use or wearing dirty contact lenses. The eye reacts to the dirty lens by developing papillae or bumps under the upper eyelid as seen in the photo below.

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Contact lenses usually decenter frequently and cloud with a mucus discharge. The eye often feels itchy and scratchy when contact lens is removed and better with the lens on.

Treatment usually involves medication to treat the allergy and changing to a more frequent contact lens replacement schedule. People prone to GPC with contact lenses may need to change to daily replacement lenses.

Pterygia

A pterygium (silent p, singular) is an invasive patch of tissue on white of the eye that grows onto the clear cornea and looks like the photo below.

Generally, pterygia (plural) begin on the nasal aspect of the eye and grow toward the pupil. Occasionally, they grow from the temporal or outer side of the eye toward the pupil. Just as any tissue needs blood to grow, a pterygium reddens when irritated and growing.

Pterygia are irritated by dryness and sun exposure and should be managed with frequent use of artificial tears and sunglasses. A recent study by Kwok and others revealed that sunlight from the side and behind actually focuses on the nasal area even when wearing sunglasses. Good sunglasses should incorporate antireflective coatings on the back surface of the lenses with as much wrapping protection as possible. Management of pterygia may also include topical medications to control inflammation and redness.

As pterygia grow, they distort the surface of the eye and can change vision. Before a pterygium encroaches on the pupil area it should be surgically removed so that vision can be restored with minimal scarring. If a pterygium is too large, even its surgical removal can result in permanently blurred vision.

If you have a pterygium, have it checked regularly and take take the proper steps to protect your eyes from dryness and sun exposure. Remember, if it's red, it's growing.

Cataracts

As all of us get older and transition into our fifties, sixties and seventies, we will develop cataracts. Cataracts develop as a natural aging process of the eye's lens. If we grow old enough we will get cataracts just as we will get gray hair. Changes in vision caused by cataracts generally create cloudy vision gradually over time and eventually lead to blurred vision that cannot be corrected with glasses or contact lenses. Printed material usually lose their contrast and become more difficult to see. Lights from passing cars often create more glare and make driving difficult at night.

(Image from Alcon)

Treatment for a cataract involves surgically removing the cloudy lens material and inserting an intra-ocular lens implant in its place. Lens implants can correct far or near vision and some premium lens implants can correct for both far and near. After cataract surgery ou may still need a pair of prescription glasses to maximize your vision.

(Image from Alcon)

Diabetes and the Eye

Diabetes affects many individuals in Hawaii and is characterized by elevated blood sugar levels. Although diabetes is detected by laboratory blood tests ordered by your physician, people who have yet to visit their physician often report symptoms of 1) always being thirsty, 2) always being hungry, and 3) having to urinate frequently.

Each year we see patients with diabetes who have yet to be diagnosed by their physicians because they choose not to see their doctor routinely. Their most common visual complaint is blurred vision and this is what we see when looking into their eyes:

Diabetic Retinopathy

The red blotches are hemorrhages in the retina of the eye. The white fuzzy patches are called "cotton-wool" spots created by retinal nerve swelling. If left uncontrolled, diabetes often leads to recurrent bleeding in the eye, scarring and blindness. Vision loss from diabetes is preventable. It requires tight control of blood sugar which results from taking the prescribed medication, exercise and eating a healthy diet.

Because diabetes is a leading cause of acquired blindness in America, all diabetics should see their eye doctor annually or more frequently depending on the severity of their condition. More advanced diabetic retinopathy requires the attention of a retinal specialist.

For more information visit: http://www.diabetes.org

Jun 19, 2007 12:28 PM

Glaucoma

There are many forms of glaucoma but they all result in progressive optic nerve damage and loss of vision if left untreated. The most common form called primary open angle glaucoma (POAG) is greatly affected by heredity with elevated eye pressure as a major risk factor. Although elevated eye pressure is a risk factor, many glaucoma patients can develop glaucoma without pressure elevation. The exact mechanism of glaucoma nerve damage is not fully understood but studies have shown that lowering eye pressure reduces the progression of the disease.

POAG has no symptoms. You cannot see it , you cannot feel it, you cannot tell that you have it. That's what makes glaucoma so dangerous. The eye pressure elevation occurs because not enough fluid drains from the eye. Current treatment attempts to decrease fluid creation in the eye and increase fluid outflow from the eye (see diagram below).

Newer medicines are being tested that protect the nerves from damage but until they are released, the best we can do is lower the pressure with our current medicines. Because glaucoma has no symptoms people sometimes have difficulty using their medicines. It can be easy to forget to use drops daily. Establishing a routine helps.

Glaucoma commonly occurs in African Americans, Hispanics and Asians but affects all ethnic backgrounds. Have your eyes checked regularly because with early detection comes early treatment and less vision loss.

Jun 18, 2007 2:32 PM

Farsightedness-Hyperopia

Hyperopia, like nearsightedness is a far vision problem. With farsightedness, the eye is too weak in power when looking at a distant object and cannot focus on the retina as it should.

If the eye belongs to an individual with enough near focusing ability, the proper amount of focus by the eye's internal lens can clear the image on the retina. This does take effort and reduces the individual's ability to focus on near objects. Because of this, hyperopia is often mistakenly thought to be a near vision problem. Focusing to compensate for hyperopia is not easy for those over the age of forty who have lost their near focusing ability because of presbyopia.

Spectacle or contact lenses would be needed to clear the vision. Laser vision correction is also an option to reshape and strengthen the eye's power for better clarity.

Nov 1, 2006 2:47 PM

Nearsightedness-Myopia

Myopia is a far vision problem caused by the eye being too strong in power. Because the eye is too strong, light coming from a far away object focuses in front of the retina and blurs as it reaches the retina.

To clear the vision, a lens must be used either in spectacle or contact lens form to weaken the power of the eye. Laser vision correction reshapes the front of the eye to weaken its power thereby clearing its image.

Nov 1, 2006 2:00 PM

Presbyopia

Presbyopia is the age-related loss of focusing that blurs near vision when people reach their late thirties or early forties. It is unavoidable. Everyone develops presbyopia. Whether you have nearsightedness, farsightedness or astigmatism, when you reach that certain age, you will experience presbyopia.

Presbyopia develops as the lens in the eye naturally ages. The lens loses its flexibility and thus its ability to change focus from far to near. Not everyone will notice the change if they have the right amount of nearsightedness or astigmatism. If the nearsightedness or astigmatism is first corrected, the presbyopia becomes apparent.

Theses are a few of the signs and symptoms of presbyopia:

1) needing more light to read text

2) holding reading material farther away to read

3) discomfort when looking at near objects

Life with presbyopia is a compromise. Correcting presbyopia requires some kind of correction to allow one or both eyes to see near. The type of correction will depend on how you use your eyes. Often, several different corrections may be necessary to maximize your vision in different situations

Although glasses and contact lenses and refractive surgery offer the best correction at this time, future treatment may involve a presbyopic lens implant. Several of these lenses are currently available (see In The News-Focusing Implants) for the treatment of cataracts. They are improving in design and functionality every year.

If you are having any difficulty seeing near things and you are in your late thirties or early forties, you probably have presbyopia. Give us a call and we will be glad to help keep you functioning at your best.

Jun 23, 2006 12:05 PM

Astigmatism - What is it?

Astigmatism is a very common optical condition that is often misunderstood. Like farsightedness and nearsightedness, it too blurs vision but only in one direction.

The first image demonstrates normal clarity.

The second image demonstrates blur with astigmatism. Notice that certain lines appear clearer than others.

Because astigmatism blurs in one direction, it can do so along any direction around the clock (e.g. 3-9:00, 6-12:00, 1-7:00). In this photo, the vertical lines appear sharper than the horizontal. It's very subtle just as it is with vision.

People with low corrections with astigmatism rarely like wearing their glasses even when they see clearer with them. Although clearer, astigmatic glasses distort one's perception of space and often cause dizziness. People often prefer seeing slightly blurred without the spatial distortion. If one were to continually wear the glasses, the brain would eventually adapt to the prescription eliminating the spatial distortion. Sometimes making smaller astigmatic changes allows for easier adjustment to the new prescription.

Another way to eliminate the spatial distortion associated with astigmatic glasses is to wear contact lenses. Contact lenses, both rigid and soft can compensate for astigmatism without creating distortion.

Progressive Optometry

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