Cataract

Just behind the iris of the eye is the lens. The lens of the eye is one component used for focusing light on the retina. Up to a certain age, the lens is also capable of changing shape so the eye can focus on objects at different distances. The lens must remain clear for a sharp image to be focused on the retina; when it becomes cloudy or forms opacities, this is called a cataract.

Photo at right: Cataract (as viewed by slit lamp)

Glaucoma

The eye is filled with two types of fluid – the aqueous humor and the vitreous humor. The aqueous humor is contained between the cornea and the iris while the thicker, gel-like vitreous humor fills the entire volume of the eye behind the lens. The aqueous humor is produced behind the iris and flows forward through the pupil. It is then drained out through the trabecular meshwork. The trabecular meshwork is located at the perimeter of the iris and cornea. Where the iris and cornea meet, they form an angle; in this angle is the meshwork which drains out the fluid. Glaucoma results from high pressure in the eye; this pressure increase occurs whenever more fluid is being produced than is being drained. So glaucoma can be the result of over-production of fluid or reduced outflow of fluid. Glaucoma is very serious because left untreated can cause blindness. It does not cause any real symptoms until it is in the later stages so the only way to know if you have it is to have your eyes examined and have the pressures measured. There are many ways to measure the pressure – all of them take only a few seconds and it doesn’t hurt. Glaucoma is treatable – there are eye drops which increase the outflow of fluid and drops which reduce production of fluid. There are also surgical options for glaucoma. But most importantly, you must be tested for glaucoma.

Photo above: Diagram of Aqueous Production and Drainage

Diabetes

Diabetes, like many systemic diseases can affect the eye. The most important change in the eye occurs in the retina and is called diabetic retinopathy. The changes occur more frequently in juvenile onset diabetes as opposed to adult-onset diabetes. Diabetes is a small-vessel disease and causes small blood vessels to bleed. When this occurs, small hemorrhages occur in the retina and can cause blindness. Diabetic retinopathy can be monitored, and when called for is treated by laser. A laser is directed at the bleeding areas and the leakage is sealed.

Photo above: Diabetic Retinopathy

Blepharitis

Blepharitis is a very common condition. It is usually caused by staph bacteria which normally reside on the lid margin. When there are too many organisims, or you are sensitive to staph, blepharitis may result. The by-products of the infection form small white crusts which are frequently only visible under the biomicroscope. The crusts can fall onto the surface of the eye causing conjunctivitis (pink eye) and can clog up pores in the lid. The pores must remain open for glands in the lid to secrete oils and mucous which are part of the normal tear film. When the tear film is out of balance (too much water and not enough oil and mucous), the eyes can feel dry and irritated. Many cases of “dry eye” are improperly diagnosed. Many cases are actually due to blepharitis. Blepharitis is never really “cured” – it is maintained.

Treatment consists of any number of several options directed at reducing the presences of staph, keeping the lashes free of crusts and flakes, and keeping the pores of the lid open. To reduce staph and inflammation antibiotic ointments are applied to the lid margins – this should only be done under the direction of your eye doctor. Lid hygiene is very important – we recommend cleaning the base of the lashes and lid margins with special lid scrubs. You can also use a mixture of baby shampoo and water. Finally – warm compresses keep the pores open and increase blood flow to the lids. The best way to apply warm compresses is by using a baked potato or hard boiled egg (with the shell removed). Both of these foods hold their heat for a long time – so instead of constantly dipping a washcloth in warm water, you can wrap the moistened washcloth around the potato or egg and hold it against the closed eye. We recommend doing this two or three times a day, for at least ten minutes each time.

Photo above: Blepharitis

Conjunctivitis (pink eye)

We are always asked when a patient comes in with a pink eye “Do I have pink eye?”. The answer is always yes – if your eye is pink or red you have pink eye. The confusion arises because what people usually mean is “Is my eye infected”.

There are many forms of pink eye. The eyes may become red just due to irritation; there may be a bacterial or viral infection, or the cause may be allergies. Frequently, people use an eye whitener like Visine to clear up the redness, but this can be a big mistake. If the eye is red due to a bacterial infection, it is red because the blood vessels are dilating to allow an influx of white blood cells to fight the infection. Eye whiteners constrict the blood vessels – so the eye looks better but the infection gets much worse. If you know you eyes are red from irritation – like from a chlorinated swimming pool, an eye whitener is fine; but remember, chronic use of most eye whiteners can cause glaucoma or rebound hyperemia. Rebound hyperemia is a loss of the clearing effect – more and more drops are needed to keep the eye white until the effect is completely lost.

Stye (Hordeolum)

A stye is a common infection which occurs on the eyelid, and is similar to a pimple. It arises from glands in the lid becoming infected, and the pores which allow the glandular material to escape becoming clogged. The best way to treat a stye is to increase the blood flow to the area and keep the pores open. We do this by keeping the area clean and applying warm compresses.
The best way to apply moist heat is to use a baked potato or hard boiled egg with the shell removed. Wrap the potato or egg in a moist wash-cloth. Both of these foods hold their heat for a long time, so constant dipping of the washcloth in warm water isn’t needed. Hold the warm pack over the closed eye for about ten minutes – try to repeat this at least three or four times a day.
If the entire lid is red and/or swollen, always let your eye doctor check it out. The entire lid being red may indicate a much more serious condition.

Photo above: Stye (Hordeolum)

Photo below: Cross section of the eyelid