Published: 06 March 2023

As an eye doctor, diagnosing a red eye can be challenging. Are we dealing with an infection, allergy, inflammation, or dryness? A common question we get is, “Doc, my eyes are red, burning, itchy, and tearing. Is this dry eye or from allergies?” The short answer is it could be one, both, or neither. We'll outline various ways these conditions present clinically and the treatments for them. The hallmark symptom of allergy – meaning if you have this symptom you almost definitely have the condition – is itching. Red, watery, ITCHY eyes are almost invariably due to an allergen, whether environmental or medicinal. It is one of the most common ocular conditions that we, as eye doctors, treat -- especially when plants are filling the air with pollen as they bloom in the Spring and then die off in the Fall. The itching occurs because an immune cell called a mast cell releases histamine, causing the itching sensation. It can be quite unbearable for the sufferer, causing them to rub their eyes constantly, which actually increases the amount of histamine in the eye, leading to worsening of the symptoms. Treatments may include: Over-the-counter or prescription allergy drops (mostly anti-histamines or mast cell stabilizers). Topical steroids (to get the inflammation under control). Cool compresses applied to the eye. Patients sometimes need to take drops every day to keep their symptoms under control. Dry eye can have many of the same symptoms as allergic eye disease, with the eye being red and possibly watery ("My eyes are tearing--how could it be dry eyes?"). The main exceptions are that people with dry eyes tend to complain more of burning and a foreign body sensation - like there is sand or gravel in the eye - rather than of itchiness. Dry eye is a multi-faceted disease with many different causes and treatments. Treatment ranges from simple re-wetting eye drops to long-term medications (both topical and oral), as well as non-medicinal treatments such as eyelid heating treatments. So how do we determine the difference? The first question I ask patients who complain of red, watery, uncomfortable eyes is, “What is your MAIN symptom? Itching or burning?” The answer will likely direct which course of treatment we take, and as those treatments sometimes overlap, you may have a component of both dry eye and allergy. That is important to distinguish because many of the treatments we use for allergies - like antihistamine eye drops - can sometimes make the dryness worse. Though neither of these conditions is 100% curable (except maybe for allergy, where if you remove the allergen, you obviously won’t get symptoms!). We have many tools in our treatment arsenal to keep the symptoms at bay. Unfortunately, dry eye and allergy aren’t the only two things that can cause your eye to have the multiple symptoms of red, watery, itchy, burning eyes. There are other problems, such as blepharitis, that can produce a similar appearance, as well as bacterial and viral infections. So before embarking on a particular therapy, it is wise to have a good exam to help you get on the right track of improving your symptoms. Article contributed by Dr. Jonathan Gerard

Published: 19 February 2023

Do you have floaters in your vision? Floaters are caused by thick areas in the gel-like fluid that fills the back cavity of your eye, called the vitreous. Many people, especially highly near-sighted people, often see some degree of floaters for a good portion of their lives. Often, these floaters are in the periphery of your vision and may only be visible in certain lighting conditions. The most frequent conditions are when you are in bright sunlight and are looking toward the clear blue sky. I know this from personal experience since I have a floater in my left eye that I most often see when swimming outdoors. Every time I turn my head to the left to breathe I see this floater moving in my peripheral vision. This is totally harmless other than when I’m swimming in the ocean and swear that sudden object in my peripheral vision is a shark bearing down on me. Some people who have floaters are not as lucky-- the floater might be in their central vision and almost constantly annoying, especially when trying to read. The second scenario in which floaters occur is during the normal aging process. The vitreous gel in the back of the eye starts to shrink as we age and at some point it collapses in on itself and pulls away from the retina. This sometimes results in a sudden set of new floaters. When that happens you need to be checked for signs of a retinal tear or detachment. As long as your retina survives that episode without any problems, the floaters themselves may stick around for a while and can be rather annoying. Most people eventually adapt to the floaters; the brain learns to filter them out so you are no longer aware of them. The vitreous can also collapse more as time goes on and the dense floater you are seeing initially may move further forward and drop lower in the eye so the shadow it is casting is less intense and more in the periphery of your vision where it is much easier to ignore. The first line of treatment for floaters has been, and still is, to learn to live with them. Once you have your retina checked and there is nothing wrong there, the floaters themselves are harmless and will not lead to any further deterioration of your vision--which is why, if at all possible, you should just live with them. This is especially true if the floaters are new because the overwhelming majority of people with new floaters will eventually get to the point where they are no longer seeing them or at least where they are not interfering with normal daily activities. If you have tried to wait them out and live with them but they are still interfering with your normal daily activities, you may want to consider having them treated with a laser. This treatment is newer and involves using a special laser to try to break down large floaters into much smaller pieces that may no longer be visible. In a study of the laser treatment involving 52 patients, 36 were treated with the laser (a single laser treatment session) and 16 people had a sham treatment (meaning they went through everything the treated group did but did not actually have the real treatment done). In the people who were actually treated, 54% reported a significant improvement in the floater symptoms while 0% in the sham group reported any improvement (no placebo effect). There were no significant side effects in either group. Some points to note in the above study: 54% of people treated noted a significant improvement in their floater symptoms with a single treatment. That’s clearly not anywhere near a guaranteed improvement. Other people have noted an improvement after more than one session, bringing the total expected improvement into the 70% range, with one or more treatments. Another point to note is that there were no significant side effects to the treatment. Although true in this small study, it does not mean that there are no risks to the laser treatment. Although rare, there have been reports of damage to the retina, optic nerve, or the lens of the eye. Another treatment that can be used to treat floaters is a surgical procedure called a vitrectomy. This involves surgically going inside the back of the eye and removing the vitreous. This surgical procedure carries a higher risk than the laser treatment and is not 100% effective. In summary, laser treatment is a good addition to the tools to deal with significant floater problems. If you have floaters for at least six months and they are central and interfering with your normal daily activities and you want to see if this laser treatment could be right for you, check with your eye doctor.