As many of you know, I specialize in ocular surface disease at Siepser Eyecare. And I can be a bit of a perfectionist when it comes to many things, particularly when it comes to the ocular surface. When I see spots of dead cells on my patients corneas that are indicative of dry eye or tears that continue to evaporate just a touch too easily, I can’t help but continue to explore what else we can do to clean that surface up.
Unfortunately, glaucoma and ocular surface disease or “dry eye” go hand in hand. A 2016 study found that 96% of those treated with prostaglandins (currently considered the gold standard of glaucoma eye drops) had evaporative dry eye. Prostaglandins when naturally occurring in the body literally cause inflammation – since dry eye is an inflammatory disease process, it makes perfect sense that taking these drops would cause dry eye. Additionally, 58% of patients treated with other types of eye drops for glaucoma also had evaporative dry eye. These are all staggering numbers! But again, they are not surprising. Many glaucoma drops have ingredients in them such as preservatives which we are now finding out through research are very damaging to the delicate tissues of the eyelids and the ocular surface in the long term.
Today I saw that a freshly released study just reported that ocular surface disease is common in glaucoma patients (we obviously knew that already!) but is not well managed. In the study they found that 97.1% of respondents agreed that comprehensive care of the ocular surface could lead to better glaucoma outcomes, yet only 22.2% agreed that ocular surface disease is being adequately managed in glaucoma practices.
In the past many physicians have tried to simply keep things in perspective. Glaucoma can be a potentially progressively blinding disease. Dry eye can be a nuisance. So dry eye always took a back burner to what we as clinicians considered to be the more urgent disease process. But we are finding out it is not nearly that simple. Dry eye can significantly impact quality of life. It has been linked in studies to depression, anxiety, poor sleep, loss of productivity at work, financial burden, and so much more. I was surprised to find that a 2011 study actually tried to put some numbers on these last points – they found the overall economic burden of dry eye disease for the US healthcare system at the time was estimated to be $3.84 billion. And that was 10 years ago!
I have personally treated patients with dry eye who for them every blink, every moment of the day causes pain and debilitating light sensitivity. Others have red eyes they are cosmetically embarrassed of because they feel it hurts them both professionally and socially (yes I get enough sleep – no I wasn’t out partying last night!). And of course the impact dry eye has on vision cannot be underestimated. I have seen patients improve from 20/70 (that’s not even legal for driving without glasses) to 20/20 on the eye chart simply by treating dry eye alone.
So what shall we do? Do we treat the glaucoma, knowingly cause dry eye, and then try to treat it on the back end? For some patients this is what we may unfortunately have to do.
But for many glaucoma patients there is another option.
When I am newly diagnosing somebody with glaucoma, I always tell them look, we at Siepser Eyecare don’t want you to end up on eye drops for the rest of your life either. In fact, it is the last thing I want for my patients. Eye drops can be expensive. We are often at the mercy of what your insurance will allow us to prescribe for you. You have to remember to go the pharmacy for the drops on a regular basis. You have to remember to take them like clockwork. You have to actually get them in your eye – this is no easy task for most people! You have to have the dexterity to instill them – picture somebody with advanced arthritis or Parkinson’s disease trying to put their vision saving eye drops in three times per day. And then we know that we very likely are causing significant dry eye by having our patients put those drops in.
So for all of these reasons over the years I have become a champion of going to the Selective Laser Trabeculoplasty (SLT) as first line therapy. Glaucoma.org does a great job explaining what it is, so I always give this handout to my patients whenever I begin this conversation.
The SLT is a simple laser procedure performed in the office that lowers the pressure in your eyes by an average of 30% – meaning that if it lowers your eye pressure enough, you may not need to take eye drops to manage your glaucoma. It takes just a few minutes to perform and it only involves putting numbing drops in your eyes. There is no downtime. It is covered by medical insurance. It is 80% effective. If it works great – if it doesn’t, there are really no significant risks because it has such a great safety profile. It leaves no visible scars on the eye. It lasts for several years and then it can be repeated. It does not affect your vision. And of course it does not cause dry eye.
When you consider all of this – why on earth would you not try the SLT first when treating glaucoma?
I’m obviously not the only one starting to think so.
The 2019 LiGHT Trial looked at the efficacy of SLT vs. eye drops for glaucoma as first line therapy. What they found was that in the SLT group 74.2% of patients achieved stable, drop free eye pressure reduction for at least 3 years. It reduced the need for further surgery at a lower cost and with a comparable Health Related Quality of Life Index. I love that this study attempted to take things like cost and quality of life into account. The conclusion of the study read that, “Based on the evidence, SLT seems to be the most cost-effective first-line treatment option for OAG and OHT, also providing better clinical outcomes.”
So what if the SLT does not work? Then you have to carefully weigh the risks benefits and alternatives of beginning eye drops vs. considering what are called Minimally Invasive Glaucoma Surgeries (MIGS). Only your eye doctor can help guide you on what the next best course of action may be for your individual case. From an ocular surface standpoint, we are starting to see evidence that MIGS procedures do spare the cornea and conjunctiva – meaning they cause much less dry eye than putting you on eye drops. But of course so much more goes into the decision making process than that.
So I’m sure you can appreciate why I, especially as an ocular surface disease specialist, now strongly recommend the SLT as my go-to first line treatment for all of my glaucoma patients.