GSLS Part 3: BostonSight Scleral; Controversies in specialty lenses

So now the fun really starts. My first notes here are from a talk on new technologies in BostonSight Scleral lenses, then the general session with specialty lens controversies.

BostonSight sponsored talk

"Lumps, Bumps and Scleral Shape: Navigating the Curves with BostonSight Scleral SmartChannel and Eaglet Eye's ESP"

Karen Carrasquillo OD

So for those of you who aren't familiar with it, BostonSight Scleral is a locally-available less expensive counterpart of sorts to BostonSight's PROSE lenses. This talk was about the technologies available for BostonSight Scleral lenses. I was keenly interested in this because it's pretty new but makes use of data from years of PROSE fitting, and I have been wanting to get a clearer sense of which types of patients they're fitting with these lenses - and by implication, where's that cutoff point where a patient needs something more sophisticated.

Have to say it was pretty impressive. The most interesting parts were specific types of patients they were able to fit - so my motivation in reporting on this is in case I have any readers with these specific needs.

Part 1 - SplineCurve and SmartChannel technologies

Dr Carrasquillo presented examples of patient outcomes using these technologies specifically for:

  • Vaulting over pingueculas
  • Vaulting over peripheral corneal cysts
  • Vaulting over a conjunctival patch graft. (This is a patient with a history of pellucid marginal degeneration and dry eye who had worn sclerals successfully in the past.)
  • Adding ventilating channels in a PKP case (i.e. full thickness transplant) case - as opposed to trying to vault over it. The patient was limited to 4-5 hours of wear time and was starting to experience complications (haze, edema, other).  They added channels, and the patient was able to gradually increase wear time without any edema or other signs of trouble, and this patient can now wear lenses up to 14 hours a day.

DrC echoed what Dr Johns says about the importance of spreading the weight of the lens over a larger surface areas

Wear time? One of my personal take-homes from this talk, reinforced by one or two others, was the specific reasons for doctors restricting their patient's wear time - and why their patient really needs to comply with that!

Part 2 - Eaglet Eye-partnering

This is advanced technology for lens design... I made a note to visit them in the exhibit hall but they were a bit too crowded tonight so I just picked up some literature and will try to circle back later. 

Dr C presented some cases treated with BostonSight Scleral lenses using Eaglet-Eye's ESP technology:

  1. A keratoconus patient with intacs and a history of crosslinking who had been unsuccessful in other sclerals intacts and CXL, failed other sclerals. The outcome was an improvement from 20/40 to 20/25, with 12 hrs/day wear.
  2. A PRK patient with very high higher order aberrations and very symptomatic at nights; the patient was already wearing sclerals but still had poor vision quality in one eye (33 year old mail). Outcome: reduction of symptoms. (Note to self: Wondering about the HOA numbers.)
  3. A dry eye patient, 45 year old female. Successfuly fitting in an 18-19mm lens on a first cut - first fit algorithm. (For context... yes, that's impressive.)

General Session: Controversies in Contact Lenses


Session introduced and moderated by Dr. Jason Nichols, who ran over some general market trends in contact lenses. Won't bore you with all of those, but a few highlights:

  • The biggest deal in contacts in 2018 was "myopia control" with either Ortho-K or soft multifocals.
  • Interest in scleral lenses still showing strong growth, with almost 50% of those doctors polled indicating that they expect to fit more sclerals in the coming year.

Now here's the real meat! The most common complications reported with scleral lenses. We definitely do not hear enough about this. These are what the optometrist who were polled indicated as their most common issues:

  • 44% midday fogging
  • 25% conjunctival hyperemia
  • 14% poor wetting
  • 7% conjunctival blanching
  • 4% conjunctival staining
  • 3% symptoms (pain, discomfort)
  • 3% visual disturbance
  • 1% cornea staining

Fogging? You are obviously in good company!

Point Counterpoint

#1: Should we be using scleral lenses in normal eyes, or not?

I LOVED this one. And honestly, while I liked the discussion, in reporting on it I would really prefer to stick with just one statement that Derek Louie made (though I think he was quoting someone else):

"Scleral lenses are for normal eyes, but not normal doctors."

I think that pretty much says everything. It certainly expresses how I feel in my world. Scleral lens success requires a level of patient contact lens support that is not readily available in most practices.

Dr Louie and Dr Jeffrey Sonsino were pro and con respectively, and apparently they've battled this out in print in much more depth in the past. But I guess I'd better share more. Dr Louie felt patients ought to be able to choose their own vision, while Dr Sonsino listed a lot of issues on the patient side (application/removal difficulty, need for specific solutions, multiple visits, complications, available of other contacts, high cost) and on the medical side ("slamming" of limbal stem cells, decreased oxygen when fit inappropriately, lack of troubleshooting expertise). Again, all that just points back to the question of how much the practitioner is willing to invest in the process.

#2: For the irregular cornea: Corneal or scleral lens?

In other words, for people like a lot of us, should you have a small 'normal' sort of RGP or a scleral that vaults the cornea?

I learned a lot from this one.

First we had Loretta Szczotka-Flynn OD arguing powerfully against sclerals in cornea transplant patients, Fuchs and Herpes Simplex (though not keratoconus). The basis for it was the safety of the corneal endothelium and how it could be threatened by poor oxygen transmissibility of sclerals. Something I want to follow up on with her and others. (I know an awful lot of transplant patients in sclerals, so presumably this isn't a simple or obvious-consensus type answer.) Learned a ton from her talk though.

Then we had Muriel Schornack OD, who didn't exactly materially disagree! “Someone has to fail a corneal lens before I’ll put them in a scleral”

However, she discussed evidence that scleral lenses can DELAY the need for transplant - though that was in transplant patients which I don't think are what Dr Szczotka was discussing much. She presented the view that scleral lenses may be an important type of “bridge therapy” in that regard and referenced both studies and patient anecdotes.

#3: Myopia control: Ortho-K or soft multifocals?

I didn't follow this one closely as I was sticking mostly with scleral lens topics.

Next up: Long Term Scleral Lens Management

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