General Session: Care and aftercare of the specialty lens
This session was moderated by Eef van der Worp, who provided context for us about risk issues for specialty lenses (note: I only reported on the scleral lens aspects) stemming from things like lens handling, care and maintenance. One of the things that he highlighted is that our lack of knowledge about actual incidence of things like microbial keratitis (we don't have enough history with the lenses and case reports etc) has implications for whether it is appropriate and ethical to use these lenses on normal, perfectly healthy eyes, as opposed to therapeutic uses.
Pauline Cho on Ortho-K and more....
Dr Cho is the optometric goddess of all things Ortho-K, that is, the special lenses used overnight to reshape the cornea instead of wearing contacts or glasses during the day. She is a wonderful presenter, and I wish I could hire by-the-hour whoever makes her PowerPoints. But... since this is off-topic for me, I confess I used a fair amount of her talk time to clean up some of my earlier notes for the blog.
Until she started touching on topics that overlapped with sclerals.
I sat up straight and started listening when she started talking about the pitfalls of storing CTL supplies in the bathroom. It started with "There's no such thing as a clean bathroom!" Then she showed some delightfully revolting illustrative animations that you simply cannot unsee.
Dr Cho also walked through the actual steps of hand-washing. They sound obvious, but... people don't actually do them, so reminders are always good. And may I just say, once again, that using the right kind of hand soap is one of the most overlooked errors in scleral lens handling! I had a conversation about this with an optometrist in the poster session earlier today.
Later on, there were more echoes of acanthamoeba awareness. Specifically: "Hands must be dry before you touch the lenses!" so you don't transfer acanthamoeba from wet hand to wet lens.
The next point that packed a lot of wisdom from my standpoint was that she insisted optometrists need to tell patients not just HOW to do something or WHAT to do, but WHY. She presented polling data showing that not understanding the importance of their instructions was the top reason (45%) for patients' non-compliance, as opposed to inconvenience, time-consuming, cost, etc.
I think I can bear that out at a personal level. I mean, I always knew tap water was a bad idea. It wasn't until I started reading in detail about acanthamoeba, and listened to how disturbed doctors feel when they get a complication that they can't necessarily treat successfully, that I finally swore off tap water myself.
Maria Walker on lens care, solutions and more
Dr Walker touched on issues relating to lens materials - specifically, deposit resistance and wettability, which continue to be issues despite improvements. She mentioned new technologies can help asses wettability such as the Medmont topographer.
In that context, she run briefly over the current methods of making the lens more wettable - (1) Plasma (which ionizes the lens) and (2) HydraPEG, which is an actual coating (polyethylene glycol based coating, "lubricious" molecule, covalently bound to surface of lens).
But... what happens after the lenses are dispensed?
(Indeed. We have an entire Facebook group full scleral lens users with HP coating... some of whom are disgruntled over anything from questioning whether the coating "works", to frustration at the refusal of providers or manufacturers to re-coat the lens, to frustration that they are so restricted in their choice of cleaning solutions to really get their lenses clean - this latter exacerbated by industry shortage affecting an already restricted set of choices.)
So Dr Walker talked about cleaners, and solution compatibility issues, like how some cleaners that have historically been preferred actually strip off the Hydra PEG (she had a slide identifying them, such as ProGent and Lobob ESC).
As regards overnight disinfection, according to the SCOPE survey, 61% (out of 663) are using hydrogen peroxide.
Then when it comes to rub cleaners: she's strongly in favor of manual (rub) cleaning, always, to remove deposits and prevent biofilm formation (which can cause infections).
Now for the equipment! She instructs patients as follows:
- Clean all accessories with alcohol and air dry
- Replace cases monthly (note: this is referring to the flat container type)
- Do not store accessories in confined containers
As regards the latter, the point came up about the sealed containers that the DMV plungers all come in. She described these as 'petri dishes for bacteria growth', which makes sense.
So I was left wondering, how OUGHT we to store those plungers? Is Dalsey Adaptives' vented version (we stock this here in the shop) good enough? How can we keep them clean if we're leaving them out exposed, for example, I keep mine in half of a DMV scleral cup case (sticking up like a toothbrush). I've never been crazy about that, and even less so after Pauline Cho's animations! Sigh. So many details. I know, I know, I should be cleaning and drying and putting them away in something that is not sealed. Anyhoo, moving on.
Evolution of "application solutions" (a/k/a preservative free salines)
She discussed on vs off label saline use. Bear in mind here, her references to "off label" refer both to solutions not labeled for contact lens use at all e.g. Addipak, and to solutions that are labeled for contacts of all types but not specifically for filling of scleral lenses e.g. Purilens. The only products that are labeled for that are the two most recent entrants to the market (LacriPure, the unbuffered one, and ScleralFil, the buffered one.)
She briefly mentioned the choice of multi versus single use containers (which in practice means Purilens versus everything else). I confess I have found it depressing at this meeting that there has been so little support for Purilens. I have a really soft spot for that company because they saved us, I mean they really filled an important gap for so many acute corneal disease patients Alcon screwed us all by discontinuing Unisol 4 with no notice, no information and no known substitutes. But I digress. Actually, on a related note, Dr Walker mentioned data showing some issues with Purilens bottles getting contaminated earlier than maybe commonly thought, which would be cause for concern and I am anxious to see that data when it becomes available.
Lens issues and complications
Doctor Walker mentioned midday fogging as an issue for 30% of patients.
Also, epithelial bogging (I don't recall seeing numbers).
Infections with scleral lenses are something we really need to know more about! The rate seems to be low but the fact is, we don't have enough data yet to even establish in any reliable way what we think the infection rates are. There are unreported cases of microbial infections. Some patients are higher risk than others. She emphasized the need for patient education and early treatment in case of infection.
Going back to salines for a moment, she mentioned data from a couple of other presenters, not published yet (and a relatively small sample size) but indicating concerns over contamination of Purilens bottles - that is, actual bottles of Purilens used by patients (in at least one case open up to 90 days). So I'm rather anxious to hear more about that. The truth is I'm concerned about common user habits with all of the various preservative free salines, in terms of whether people understand enough about keeping clean and discarding them on schedule.
Dr Walker's final points were:
- We really need a specific scleral lens solution (hear, hear. But even before coming up with more solutions, I'd like to see us better understanding the issues we have with the current ones at all levels - from ingredients to pH to patient comfort to safety)
- Patients need detailed instructions that work with their lifestyle. (Amen to that.)
Kelsy Steele presented on the dangers of tap water exposure through contact lenses, and the various ways in which that happens.
First, she did a little devils's advocating: There's a letter to the editor by Mirsayafov et al (Eye & Contact Lens, 2018 raising questions about efficacy of the tap water exclusion concept, citing things like regional water quality variances, the question of whether we can remove cleaners adequately without tap water, the difference between soft and rigid gas permeable lens materials and the low risk of disease from tap water. (I just read that letter tonight and I'm going to revisit that separately at some point because it did raise some interesting points.) Anyway, moving on.
About water exposure opportunities i.e. how does water get on our lenses
- Lens storage case (rinsing with water)
- Rinsing contacts with water (2017 CDC/CLAY study, 91% of GP wearers do this)
- Showering - and she pointed out that it's not just a matter of having water aiming at your face - the mist from the shower can do it as well. (Aerosolization of water-borne pathogens)
- Ubiquitous, free-living protozoan; 2 forms; 24 species, 18 genotypes; 2 most common types
- Isolated in natural and municipal water supplies - everything from bottled water to dental units, to rivers to dialysis machines, to eyewash stations.
- Ran through signs & symptoms
- Often gets misdiagnosed as herpes keratitis
- Early detection important
- Outcomes poor
- Pain out of proportion to corneal signs, but not always... some patients have no pain.
- INCIDENCE: Hard to determine! Orphan disease! Varies regionally. 2 per million in US; 20 per million in UK; 4 per 10k in australia. UK outbreak beginning 2010/11; another in Netherlands beginning 2009.
- Are we seeing a global increase??? We don't know - waiting to learn more.
- RISK FACTORS: CTL wear 90%; orthoK; water contamination: water quality, topping off solutions, homemade saline solution, chloride release disinfection systems
- Outbreaks: 80s-90s - homemade saline, chloride release disinfection, poor hygiene. 2003-2007 - correlated with CMS contact lens solution, but, interestingly, incidence of AK didn't improve after that product was taken off market. Why?
Other water-borne pathogens (in addition to acanthamoeba)
- Pseudomonas aeruginose
- Serratia marcescens
- Handful of others... aaak stop I'm getting dizzy!
But what about disinfection solutions?
- The FDA does not require that these solutions (yes, including hydrogen peroxide) prove that they can kill acanthamoeba. It's complicated.
Ugh. It's pretty hard to listen to this and be OK with tap water afterwards.
Solution preference by lens type - they have their own data - 50% in scleral lens prefer H2O2. She notes an interesting anomaly in their survey data: For some reason, even while at least half of doctors are recommending hydrogen peroxide for sclerals, the vast majority still are recommending 2 step cleaning for for corneal RGP lenses (i.e. the little ones). Why? Doesn't make sense, they're the same materials.
Does water avoidance work?
Seal study from 1999 - required water avoidance - after 1 month, there were no signs of acanthamoeba, no pseudom, no staphylococcus aureus in 150 subjects.
Dr Steele concluded by asserting that best practice is no use of water, period, not just in soft lenses, but in RGP and scleral lenses too.
Dr. van der Worp then mentioned that in the Netherlands they are recommending against Ortho-K myopia control across the board specifically because of acanthamoeba keratitis
Dr Kading jokingly brushed Dr Steele's entire presentation off as "fake news", likening the incidence of AK to the incidence of people dying by driving off cliffs. (Not the greatest analogy, perhaps, since that's not a behavior most of us engage in every morning before our first cup of coffee, but good enough for a laugh.)
The main thrust of Dr Kading's presentation, however, was on the very meaningful topic of how optometrists can reconcile what they know to be best practice based on prevailing science, with the practical realities of their busy practices, limited time to educate patients, and the patients' own needs and lifestyles.
It's all, he says, a matter of a balancing act - time, and money. Recognizing things like the financial hardship of the cost of solutions.
He brought up the question of the conversations with patients, and optometrists' need for clear procedures about what should be the role of the optometrist versus another staff member in that process. He strongly recommended writing every down. (In scleral lens practice, that ought to be a no-brainer. ALL scleral lens patients need EVERYTHING written down. Scleral lenses are complicated for us, and we need careful training, reinforcement and most of all written materials to refer back to after we get home and start trying to remember it all.)
He also urged attendees to consider carefully how they are going to present lens care protocol information, and how they and at what interval they are going to follow up and reinforce.
As regards what to tell patients, he recommended:
- Make it SIMPLE but significant
- Plan for repeated reinforcement (my note to myself on this one was... it assumes the patient will come back! drop-out rates are a problem in scleral lenses)
- Get creative, for example, give them a quiz
- Encouraged more frequent follow-up for new scleral lens users.
There was a bit of Q&A and discussion afterwards, including:
Dr Walker pointed out that even doctors who tell their patient "No tap water!" are sometimes... using water in their practice!
Dr Steele agreed, saying they noted this conflict in practitioner survey data!
Clearly, "abstemiousness" is a relatively new concept out there that will take time to be fully adopted....
There was fairly broad agreement that simple rules are best. Once you start making exceptions, it gets too confusing and too hard for patients to remember. On the other hand, Dr Kading pushed back on on this, on the basis that there is usefulness in giving additional guidance to patients who you know are going to push the limits with their lifestyle. For example:
What do you do for swimmers? Dr Kading: Warn patients - "Wearing your lenses while swimming, without swim goggles, is NOT healthy, it's high risk. But... if you're going to do it, here's how to mitigate" (e.g. wear daily disposables and throw them away same day).
What about showering? Dr Walker: Shower BEFORE you put your lenses in. Dr Kading: But... what about those who always shower after the gym in the middle of the day? "We DON'T recommend it, but... if you're going to do it anyway, here's what we recommend...."
There was a little more talk about lens cases and lens size and what to do with hydrogen peroxide when the lenses are too big for the Alcon case (not closing the baskets, or using the PROSE case that we have here at the shop) and then it wrapped up with Dr Kading's advice:
Make it [patient instructions] simple but significant.