As riders and horse owners, we spend a great deal of time outside in the elements showing, training, working, teaching, and riding for recreation. While everyone is aware of the dangers of ultraviolet (UV) radiation on our skin and most of us dutifully slather on sunscreen, we tend to overlook the most important and delicate organs of all – our eyes.
The UV Threat
The sun’s rays permeating the earth’s atmosphere create four types of UV radiation: UVA, UVB, UVC and HEV. While UVC are absorbed by the ozone layer and do not pose a threat, exposure to UVA and UVB rays can have adverse effects on your eyes and vision. HEV rays can also deeply penetrate the eye and damage the retina, especially in people with low blood plasma levels of vitamin C and antioxidants. Long-term (and even short-term) exposure to all of these dangerous rays can cause significant damage to the eye’s surface tissues, as well as the cornea and lens, and can even burn the surface of the eye, much like a sunburn on your skin.
Short-term, unprotected exposure to excessive amounts of UVB radiation, such as you would encounter during a long, sunny day at a horse show, can result in photokeratitis. This is an inflammation of the cornea made worse by wind and dusty conditions, and is often called “snowblindness” even though it can occur at any time of the year. Symptoms include pain, red eyes, a “gritty” feeling under the eyelids, excessive tearing and extreme light sensitivity. Fortunately, the effects of photokeratitis are usually temporary and rarely result in permanent eye damage. Applying ophthalmic antibiotic drops, ideally while keeping the eyes closed and/or patched, can provide relief until the symptoms subside.
Long-term exposure to UV radiation can cause more serious conditions. One of these is the formation of a pinguecula – a yellowish, raised patch on the white sclera of the eye believed to be a protective response to excessive sunlight exposure. It may feel like there is something in your eye, especially if you are a contact lens wearer. This unattractive, non-cancerous growth can occur on either side of the cornea, but usually appears on the nasal (inside) edge and may increase in size over the years.
An inflamed pinguecula causes mild to moderate ocular discomfort and a red mound. Pingueculae may clear up on their own, or can develop into more serious pterygia (see below). Unless it is atypical (i.e., constantly inflamed or causing a great deal of discomfort), eye doctors tend to leave pingueculae alone; applying artificial tears or topical vasoconstrictor drops (such as Visine and Murine) seems to help.
Pterygia are small-to-large benign growths in which the conjunctiva (the transparent lubricating mucous membrane that covers the eyeball) grows into the cornea directly beneath it. It usually presents at the nasal edge of the eye. While most people do not experience any symptoms, a large growth may cause astigmatism (a misshapen cornea causing vision impairment).
Treatment depends on the pterygium’s size and whether it becomes inflamed; your eye doctor may prescribe lubricants or a mild steroid eye drop. If it becomes necessary to remove the pterygium, an ophthalmologist can perform the procedure in his office or an operating room. The surgery takes about half an hour, and the patient will likely have to wear an eye patch for 24-48 hours. While the recovery literature suggests that patients should be able to return to their “normal activities” the next day, this really does not apply to horse owners, as the environment must be dust-free for up to six weeks. Diligently protecting your eyes with goggles or tight-fitting glasses during this time, especially while performing chores like grooming, riding or mucking out, may be necessary.
Pterygia have a nasty habit of returning; the recurrence rate can be as high as 50 or 60 percent. To prevent this regrowth, your eye surgeon may graft a piece of eye tissue onto the affected area, which can lower the recurrence rate to about 5 per cent. Drugs such as mitomycin and steroid eye drops may also be applied topically to slow regrowth.
Dr. Barry Emara, MD, FRCS(C), is an ophthalmic surgeon with a busy practice in Windsor, ON, an area which is dubbed “Canada’s Sun Parlour” because of its hot, sunny summers. On average, he sees 15-20 cases each year involving pterygia and pingueculae, about half of which necessitate surgical removal.
He notes that the majority of these patients are people who spend a lot of time outdoors – golfers, construction workers, farmers, tennis players, and riders. In this country, the surgery is usually covered by provincial health plans such as OHIP.
Research has shown that even limited exposure to UVA radiation over a period of many years may also increase the chance of developing, and hasten the premature onset of, cataracts and macular degeneration, and may cause irreversible damage to the retina, the nerve-rich lining of
the eye that is crucial to sight. Just as people with fair skin burn more easily, people with blue, grey, green or hazelcoloured eyes can sustain damage more quickly. Exposure to excessive sunlight is also one of several factors contributing to various eye cancers, although genetics, eye colour, and propensity for moles are also important contributors. Even skin cancer of the eyelids and surrounding area is becoming more prevalent.
Top show jumper Ainsley Vince has become the poster girl for taking steps to avoid the damage UV radiation can wreak. “Painful bouts of really red, sore eyes had been bothering me for years,” she said from Florida, where she was eight weeks into the long (and sunny) Winter Equestrian Festival. “Everyone said it was allergies.
I must have seen over a dozen doctors (in Canada), and if even one of them had told me to wear sunglasses, I would have done it starting that day.” Vince was finally correctly diagnosed with pterygia by a California opthalmologist, and subsequently had two surgeries in Florida. She notes that eye doctors in the southern States see this kind of condition far more often than their northern counterparts. Her Canadian doctor told her he performs seven or eight surgeries to remove pterygia per year, while her Florida surgeon does seven a week.
Vince underwent her second surgery immediately after the Tournament of Champions in 2010. The operation/graft procedure is relatively simple, but not without some discomfort, according to Vince. “It hurts enough. It feels like you have sand in your eye for a few days.” Dr. Emara explained, “Patients experience one or two days of pain, which then settles as the sutures dissolve.”
As previously mentioned, following the rules for recovery can be tricky. “They told me to stay out of dust for six weeks,” said Vince, laughing. “The only place I thought I could safely do that was at my own farm, because we have the European footing. I was very careful.” She also wore glasses at the Royal to help protect her eyes from the dust, instead of her usual contact lenses.
Vince has endured some kidding since she donned her sunglasses. “When I first started showing in them, everyone made fun of me, but you know what? I don’t care,” she said, noting, “I find a lot more people are wearing sunglasses now than five or ten years ago.” And a lot more riders are having the surgery to remove pterygia, among them fellow show jumper Eric Lamaze.
Gotta Wear Shades
Wearing high-quality sunglasses is your best defense against eye damage – period. Riders are often reluctant to wear them, however, citing a lack of depth perception, loss of peripheral vision, or fear that the sunglasses might shatter during a fall and cause traumatic eye damage. These concerns are shared by athletes in a number of sports, such as tennis, volleyball, golf and parasailing. Manufacturers have taken these valid concerns into consideration, creating many impact-resistant sport models.
Vince, who currently wears Ray-Bans, admits that you have to look at a lot of models, and suggests consulting with an eyewear specialist. “It’s hard to find ones that fit correctly with your helmet.”
When choosing sunglasses for riding, the expression “you get what you pay for” is especially accurate. The cost of manufacturing sunglasses that meet or exceed the minimum safety and UV-resistance standards are a major factor in their price. Make sure that they:
· block out at least 99% of UVB rays and 95% of UVA rays. Check the label for the sun protection rating.
· have wrap-around frames and large lenses that fit close to the eye
· are made from impact-resistant polycarbonate or Trivex
· contain polarized lenses to reduce glare from reflective surfaces, providing increased visual clarity and depth perception.
· have lenses that are not too dark, which can cause the pupils to dilate and allow in even more UVA radiation Consider yellow-tinted lenses, which are a favourite with outdoor athletes and hunters because they provide excellent depth perception and low-light contrast, and work well at night or in foggy conditions. Even if you wear contact lenses that have UV protection, you still need to wear sunglasses, as UV rays can still damage the eye tissue that is not covered by the contacts.
Both UV and HEV rays are the most intense between 10 a.m. and 2 p.m, so whenever possible, try to get out of the sun during those hours, or at least swap your riding helmet for a wide-brimmed hat when you’re off your horse. Said Vince, “You will never see me out at a horse show without a visor or a hat of some sort.”
Reflective surfaces such as snow, sand, and pavement multiply the intensity of the sun’s UV rays, and sunglasses should be worn during the fall and winter as well. Some medications can increase your eye’s sensitivity to light, such as tetracycline, sulfa drugs, diuretics, tranquilizers and birth control pills. And finally, make a yearly checkup with an eye doctor part of your regular health regimen – and be honest when he or she asks you how much time you spend in the sun.
“You only get one shot in life with your eyes,” warned Vince. “Sun, wind, dust and pollution – we all operate in this perfect storm all day, every day.”