Friday, March 18, 2011

Grab those shades!

Picture on the left: An iris melanoma, which has an incidence rate of about 4.7 people per million Americans. (photo courtesy of the Mayo clinic)

A good pair of sunglasses could save your life! Although rare, eye cancers can occur in adults due to UV light exposure from the sun. Also, prolonged exposure from a tanning bed, artificial lights, or other UV light sources may damage the eye. Therefore, please be sure to wear UV light protection whenever you are outdoors or exposed to UV light. Even if you are not looking at the light source, the beams may still penetrate around the outside structures of the eye and cause ocular complications.

Dr. Paull had an up-close and personal experience with this during her first year of practice. A 55 year-0ld male patient had a suspicious brown spot in his otherwise clear blue eyes, and Dr. Paull noticed that it had not been documented in any previous exams. He was sent to Duke for some special tests, and it was determined he had a rare iris melanoma that was growing very rapidly. It was quickly excised, before spreading to other areas of his body. He stated that he had been a lifeguard for many years of his life, and he often didn't wear sunglasses while out in the sun.

Thank goodness that large sunglasses are definitely in style. Keep those shades on and you are not only protecting yourself from cancers, but also from eye diseases like cataract and macular degeneration. Dr. Paull sees patients every day that have 'sun spots' or tiny raised areas on the outer part of their eye called pinguecula. These areas can cause irritation and can grow into larger structures called pterygium that may eventually blur vision.

Therefore, Dr. Paull wants to see all of her patients (young and old) to be sunglass models this spring! Grab your favorite pair of sunshades when enjoying this beautiful weather!

(more information may be found at: http://www.webmd.com/melanoma-skin-cancer/tc/eye-intraocular-melanoma-treatment-health-professional-information-nci-pdq-general-information#s2.1)


Sunday, March 13, 2011

Goggles and glaucoma? What you need to know before purchasing your next pair of goggles.


Make sure your goggles fit properly before swimming! Studies have found that tight, small goggles can actually raise the pressure of your eye to dangerous levels. Did you know that the pressure exerted by certain small racing goggles can raise a person's eye pressure 13 mm? For example, if your normal eye pressure was 15, then when you were wearing the small goggles, your pressure would be 28! The average pressure is between 10-20mm, and if it raised above 21 for prolonged periods of time, optic nerve damage can result and glaucoma can develop. This leads to a gradual loss of peripheral vision and can eventually cause tunnel vision or blindness if not controlled.


The picture above shows several styles of goggles, of which the bottom left goggle is the safest. If in doubt, just bring an extra pair of your goggles in to our office and we can remove the front part and measure your pressure while you wear them in our exam room (see picture E)! Courtesy of Morgan et al, http://bjo.bmj.com/content/92/9/1218.full .

This is not intended to suggest that swimming with goggles can lead to blindness! However, for the serious swimmers, it is in their best interest to use large goggles that do not press too hard on the orbit of the eye. For example, in the above picture, the best goggle style was letter C - it has a continuous interface between the two eyes and the pressure exerted on the orbit was not clinically significant. However, stay away from goggles that look like the one pictured in letter A - that particular style raised eye pressure an average of 5mm. The goggles pictured in letter B and D only raised the pressure by about 1.5mm.

For more information, please read the interesting article published by Morgan et al. at: http://bjo.bmj.com/content/92/9/1218.full. In this study, the measurements had to be taken outside of the water. When under water, the pressure of the water could exert even more force on the orbit, potentially increasing the pressure more. However, there is some good news for swimmers! It is also estimated that 20 minutes of any aerobic exercise like swimming actually decreases eye pressure by about 4 mm.

Therefore, the moral of the story is to keep swimming! However, make sure you are wearing comfortable, nice large goggles. I found a good pair on Amazon.com (pictured below): http://www.amazon.com/Aqua-Sphere-Seal-Swim-Mask/dp/B000EORGXQ/ref=pd_sim_sg_4 .
Happy swimming!

Saturday, March 5, 2011

Tinted glasses: More than just cosmetic




from Dr. Levy:



I had a patient this week who presented with a complaint that "everything looks green, especially when I'm reading off of white paper." As she was an elderly retiree, and reading was one of her few pastimes, this was especially troubling to her. Psychological studies have shown that a green color near the center of the visible spectrum of light wavelengths is supposed to be the most pleasing to the human eye, but it wasn't to this frustrated lady.

My first thought was that she may have had cataracts developing, as people will report their vision taking on a yellow, orange, or brown color as cataracts develop. Maybe if hers were turning yellow, it was such an intense yellow she may have perceived it as green. However, she had already had cataracts removed from both eyes several years ago, so that was not the case. I then wondered if her implanted lenses had some kind of green tint to them, maybe an ultraviolet blocker, but examination of the implanted lenses revealed them to be crystal clear, and ordinary implants.

My next thought was that maybe her maculas were starting to degenerate, and the blue, yellow, and red receptors were degenerating faster and earlier than the green receptors. I went along with that as a working hypothesis and tried to figure out how to solve her problem. Half from memory, and half from pulling up a color wheel on the internet, I identified the color opposite green, found that it was red, and asked one of the opticians if we had a pink or red colored tint sample that I could have her look through. We found a pink/brown combination lens, and then a pure pink lens, and held them up in front of her reading glasses. Immediately her hunched-up shoulders relaxed, she let out a sigh of relief, and said, "Yes. That's perfect!"

There is a small subfield of optometry know as Syntonics, that promotes the idea that colors, filters, and tinted lenses can affect how we perceive the world and how our visual systems function.
While there isn't a lot of published scientific evidence to back it up, this appeared to be one case where we could solve a functional visual problem, with a simple tinted lens that would normally have been used for cosmetic purposes!