By: Paul M. Karpecki, OD, FAAO Clinical Director – PECAA
I first have to apologize I wasn’t able to participate at PECAA’s Annual Meeting this past month. It’s the first time since I began my role as clinical director at PECAA that I’ve not been present. I heard it was a great conference once again, but I also received an exorbitant number of emails and calls from my PECAA colleagues regarding dry eye. So let me answer some of those questions I received as this month’s column.
Is osmolarity truly of no value?
This was the most common question I received so I’ll address it first. I think whoever was the speaker on dry eye disease probably didn’t say that osmolarity was of no value as it is a 5 second test that has the highest predictive value in diagnosing dry eye of any test available. It was listed as one of the essential tests in the ASCRS Preferred Practice Guidelines that was published this past month, as well as TFOS DEWS II global test recommendations in the diagnostic methadology section. I personally couldn’t imagine running a dry eye clinic without osmolarity testing anymore than I could manage glaucoma without OCT. But I believe the speaker was simply saying that you can still manage dry eye without it (just as you can manage glaucoma without OCT but not as effectively). I also feel that unless dry eye is a major focus of your practice and you have the ability to dedicate one tech who gets very good at osmolarity testing, you should begin with other testing such as vital dyes and tear film breakup measurements. Finally I believe that regardless of what equipment or diagnostic tests we have ranging from meibography to tear meniscus height assessment and MG expression, we have an obligation to take care of this enormous patient population. So basically work with what you have and this part of your practice will evolve to where osmolarity testing makes sense.
Does hypochloorus (HOCl) acid kill demodex?
The only study I could find on this was actually a poster by Alan Kabat OD, that compared high concentration tea tree oil to HOCl to mineral oil (as the control). In this study he basically plucked demodex parasites off lashes and placed them under a microscope slide in one of 3 solution as outlined previously. The results showed that after 3 hours all of the demodex combined with 50% tea tree oil were killed but almost none of those in HOCl were affected any more than the control group in mineral oil.
Others have stated that HOCl kills the the food supply and indirectly kills demodex. It’s unlikely as demodex is a scavenger that survives on a lot more than bacteria and quite frankly, even though I like HOCl as a treatment, it doesn’t eradicate all bacteria including our natural fluora (fortuantely). Demodex also eats meibum, hardened oils, keratin, blood and anything else it can scavenge. That being said, HOCl acid is an effective antimicrobial for bacteria and possibly even for adenovirus. It is relatively natural as our white blood cells essentially produce HOCl and it’s very effective. I like using it in moderate to advanced cases of staphylococcal or bacterial blepharitis, then moving back to surfactant cleaners at times. If there is an issue with HOCl acid solutions it is that once opened many of them become nothing more than saline (as the pH drops) within 1-2 months. For that reason I prefer brands that are stable after opening for 18-24 months such as Zenoptiq (Focus Labs) or SteriLid Antimicrobial. Zenoptiq is in a blue bottle and is stable for over 18 months even after opening and comes in both a spray and a gel.
So what is the best treatment for demodex?
Currently there are only two options as Cliradex is not available (although it could be available again once this paper is published). These are blepharoexfolioation or mechanical cleaning with low dose tea tree products– and the most effective approach I have seen is with Blephex. This debulks and mechanically removes the pathogens. It’s important to wait 10 minutes between treatments as it seems like during that time the demodex come to the surface and that second treatment has a greater effect. The other is the Oust Swabstix from OcuSoft with higher concentrations of tea tree and sea buckhorn oil. My preference from a comfort perspective is Blephex but these are the two treatments I’ve seen be most effective for demodex. Don’t forget to include daily at home maintenance after these in-office treatments. Maintenance is best achieved with a low concentration tear free product such as Oust in the canister with tea tree, Cliradex light, SteriLid and my personal preference, Oasis Lid and Lash with Tea Tree.
The DREAM study states that there was no difference between fish oil and placebo in the management of dry eye, does that mean we shouldn’t recommend it anymore?
It is true the DREAM study showed no statistical difference between a high grade triglyceride form of fish oil and refined olive oil (as the placebo) in a large scale, multisite study. The fact is that the fish oil had a highly statistical improvement in dry eye signs and symptoms, it’s just that the placebo did as well. I think the reason for this is the study involved far too many variables as it was deemed a ‘real world’ study meaning patients could maintain treatment with other products ranging from lid scrubs to Xiidra. Also olive oil, even though refined to remove anti-inflammatory properties, may not have been the best placebo choice. But I think the DREAM study shows me that pure fish oil, although effective, may not be enough and combination products such as HydroEye (combines fish oil with GLA from black currant seed oil) may be more effective as I’ve seen in my own clinic.
Has the use of thermal pulsation like LipiFlow decreased the need for other DED treatments like Restasis or Xiidra?
The answer is yes in some cases but no in the majority of cases. Let me explain because it has to do with what stage of disease you diagnose. Like any disease process, the sooner we treat the patient the better. So if a person is pre-dry eye such as having early meibomian gland dysfunction, a thermal pulsation treatment alone may be sufficient. However most patients only seek treatment or most doctors only diagnose the disease when it is moderate or advanced. At this point there are four elements to most cases of evaporative DED and that includes obstruction of the meibomian glands, biofilm or blepharitis, inflammation and tear film instability. So treating just one element (even as good as LipiFlow may be) is usually insufficient at this stage of the disease. And like blepharitis, maintenance with options such as a Bruder mask, are imperative just as brushing and flossing one’s teeth still occurs after the dental cleaning. Here are options in each category that may work most effectively and be sure to select at least one treatment from each category to achieve success. Keep in mind that aqueous deficient dry eye has a different protocol but over 80% of all dry eye involves an evaporative component so this chart provided may help most dry eye.