Sclerals and contact lens DE

[odydnas]

There are a lot of studies and evidence here that contact lens can cause a lot of tear film and sometimes permanent dry eye problems. Are scleral lenses exempt from these types of problems? I'm curious as to whether or not sclerals can be worn for a lifetime, or do you start accumulating problems later on from longterm scleral use similar to regular CL use. Perhaps Rebecca can comment on this?
Thanks.

[Stanza]

I've wondered this too...

[Rebecca Petris]

What a great question.

And I really don't have the knowledge to answer it intelligently.

Not that that has ever stopped me from offering opinions, LOL.

So here are some random thoughts I have on the subject.

First, I don't really know what "contact lens induced dry eye is" other than a bucket into which a lot of undetermined dry eye can be tossed as a convenient explanation. So that's one thing that would have to be sorted out: What conditions does one have that are either revealed by contacts (i.e. you become symptomatic only when wearing contacts) versus conditions that are exacerbated by contacts versus conditions that are actually caused by contacts. On that latter subject, there's a lot of anecdotal stuff but surprisingly few scientific studies. I remember seeing something awhile back about reduced meibomian gland function from long term contact lens wear, but these studies often raise as many questions as they answer.

Second, it has to be borne in mind that all these references to contacts and dry eye are almost always related exclusively to SOFT contact lens. There's a world of difference between a soft lens – no matter how "dry eye friendly" – and a gas permeable lens. So the question is, what's the mechanism by which a soft lens theoretically can cause or exacerbate dry eye, how often does it happen in reality (risk factor) and then to what extent can a gas permeable lens do the same thing? Does a gas perm lens have any problem-causing mechanisms that soft lenses don't? And what about the size factor?

Questions, questions, questions. And that's just about soft vs gas perms. Then we come to sclerals, which are a different animal yet. They are made of gas permeable materials but they're quite different from standard "gas perms" and from soft lenses.

1) They're larger.
2) They do not touch the cornea.
3) They hold fluid over the cornea.

So when you're wearing sclerals, which by the way are technically classed as a prosthetic device, any mechanism by which the contacts could theoretically affect corneal nerves, for example, probably will not apply, because there's no contact with the cornea. On the other hand, if contact lenses are foreign objects, a scleral is a really BIG foreign object to have in one's eye all day long. What's it doing? The real question is where it interfaces with the underside of the eyelids. And I don't have any information. I need to go back and bone up on the studies (thankfully there are quite a few) and see what they say. Might see if I can get a doc or two to weigh in here as well.

[Aaron77]

I wonder if the relief that you get from sclerals while wearing them can actually improve the feeling of your eyes when you have them out?

Does the condition of your corneas actually improve from scleral use... thereby giving you relief even when they are out?

[Rebecca Petris]

That depends on the condition. They are sometimes used as a short term treatment to promote healing.

[Aaron77]

Rebecca, did you find that Dr. Steven Lee's lenses helped out with the dry eye pain? Not sure if his wavefront lenses would be considered scleral?

The simple computer work that I've been spending my days working on as of late is pretty hard on my eyes - trying to find some type of solution so I can get productive again. I hope to talk to my opthamologist in the next week when I pick up my Restasis but I figure he'll be against the idea of going to contact lenses.

[Rebecca Petris]

I was not fitted by Dr. Lee. I just spoke with and emailed with him a long time ago and I know other patients of his.

[odydnas]

Thanks Rebecca for the informative post and all the questions it raises.

Does anyone know if scleral lenses from private optometrsits (such as Dr. G) any different from the BFS ones? What makes the BFS so special and so much more expensive and time consuming than say, Dr G's sclerals?

[Rebecca Petris]

I think that DrG's are in a class by themselves i.e. not to be lumped with lenses fitted by other optometrists because (among other reasons) he uses proprietary scanning technology.

BFS uses proprietary manufacturing technology and lens designs.

Most others are commercially produced lenses with far more limited ability to customize.

Can't really speak to the differences at a technical level because I don't know. However, BFS has a totally different cost structure than any other provider because they are a nonprofit that does nothing else, and have a facility and staff and all the technology to cover. Their actual cost of producing BSLs is considerably more than whatever they charge. I think it's something like $12-13k or something. The difference between that and what they bill insurers for is covered by their donor base.

[ALK-O'd]

This is an interesting topic. I myself am a wearer of semi-scleral lenses and may need to someday “graduate” to full-sized ones. But I share the concern regarding long term use. While full sclerals don’t touch the cornea, they do trap relatively stagnant fluid against the cornea for long periods. Could this in itself be harmful in the long term? My OD had mentioned to me before that he does not like full sized scleral lenses for exactly this reason although he didn’t get into lengthy detail about it. Perhaps I’ll probe him more on the subject when I see him next month.

[Rebecca Petris]

ALK-O'd this was a classic problem with sclerals and I think traditionally it has been addressed primarily with fenestration holes and with removing and refilling the lenses. However I think that with the most advanced lenses there are other technologies in lens design to address this as well. I'm not sure if what I am going to see is completely current as there have been so many rapid evolutions in the design that I have not kept up with lately but I think with the BSLs the underside of the lens is designed with tiny channels and the blinking mechanism 'pumps' a certain amount of fluid out so that there is a certain amount of fluid exchange going on during lens wear. In fact I know this to be the case with my own, because I've experimented in the past with filling them with NutraTear, which is pink due to Vitamin B12 and so it's visible. In time during the first hours of wear it would drain out. I know in some cases the fluid exchange is actually problematic for example letting in mucus & debris, so sometimes people use something more viscous to actually inhibit exchange.

[ALK-O'd]

“Does anyone know if scleral lenses from private optometrsits (such as Dr. G) any different from the BFS ones? What makes the BFS so special and so much more expensive and time consuming than say, Dr G's sclerals?”

Most ODs nationwide that fit scleral lenses work with commercial brands such as the Jupiter Lens from Medlens Innovations. These lenses usually come in standard sizes and usually only edge thickness and fenestrations can be altered.

From what I understand, the unique aspect of Dr G’s methodology is primarily in his fitting approach. He claims to have the ability to produce a topographical scan that extends out to the sclera which he is then able to use to design a custom mapped scleral lens from. A local contact lens manufacturer that he works closely with then makes the lens for him. However, I believe he only started designing scleral lenses in 2007 (http://www.globalrefractivesolutions...etriclens.html)

BSF also creates custom designed sclera lenses, but through a different approach. They begin the fitting process using lenses they already have made to narrow down to a close fit. THEN, they use specialized engineering CAD like software and mathematical “spline” algorithms to tweak the design of the premade lens to more precisely match the contour of the eye based on observations on how the eye reacts (i.e. vascular impingement, conjunctival blanching, sclera indentation etc…) to the premade lens after it has been on the eye for several hours. They have there own in house lathe linked to their computers (I’m an IT Director – I gotta get up there someday and see all their toys!!) which they use to blast out the newly designed lens. The process is repeated several times until it’s determined that the optimal design has been achieved. (http://www.bostonsight.org/doctors.htm)

BSF’s lenses differ somewhat from most commercial sclerals in that they also have some sort of tiny fluid ventilation channels incorporated into the design to aid in tear exchange. Most commercial lenses either rely on fenestrations (which can allow air bubbles into the lens which can blur vision and cause the lens to settle back on the eye) or simply motion on the Z-Axis (in towards and away from) the eye. By having a more precise fit, BSF’s lenses are able to be designed without fenestrations (referred to as a “sealed” design) which helps keep out the air bubbles and helps to prevent the settling back on the eye.

Of note, Dr G. put a post over on the sclerals forum on February 6, 2007 (I can’t figure out how to get a hyperlink directly to it but it’s still there) stating that the Tru-Form (one of the manufacturers he works with) lenses have a similar fluid ventilation design to that of BSF’s lenses. The designs may have changed by now but I found that interesting. Here’s what he said:

“In addition to the BFS, scleral lenses are now available through three manufacturers here in North Texas, and those manufacturers are Tru-From Optics, Essilor and C&H Optics. The Tru-From design is vented similarly to those produced by BFS, while the Essilor lenses are from Innovations In Sight. Both are 18.2 and 18.4 mm”

So, all around as far as the lenses themselves are concerned, both BSF’s lenses and Dr G’s scleral lenses are probably very similar to each other but may differ a bit more from commercial sclerals. Both Dr G’s lenses and BSF lenses also get plasma coated which help increase the lens material’s wettability. Not all commercial lenses are plasma coated.

BSF of course is a facility specifically focused on fitting and designing scleral lenses and has been doing so for over 15 years where Dr G fits all sizes and types of contact lenses and has only begun designing scleral lenses more recently. BSF’s lens design was also approved by the FDA in 1994 as an ocular surface prosthesis (for whatever that’s worth – then again the FDA also approved LASIK way back when so, I guess never mind). Cost-wise, according to BSF’s site (which doesn’t get updated very often so the price may have changed) a pair of BSF lenses will run you $7600 –BUT- in some cases will be covered by insurance. A pair of Dr G’s sclerals will run in the neighborhood of $2500.

BTW, Dr. G and BSF are not the only custom scleral lens designers in the U.S. Here’s a slightly bizarre link to a doctor in Ohio who is now able to make a “notch” in a scleral lens to accommodate patients with scleral obstructions: http://thesclerallenscenter.com/?page_id=19

[odydnas]

Wow, thanks for the info ALK and Rebecca!! Where did u get your lenses ALK? Looks like I'm going to be heading down the sclerals path end of the year or beginning next year and I wasn't sure whether to see a optometrist, Dr. G, or BFS. Now I know that the best way to spend my money and best chance of seeing whether sclerals will work would be either Dr. G or BFS for a more custom fit. I think that given the slight differences between Dr G's and BFS sclerals would probably make some patients have better results with Dr G's and some patients will get better results with the BFS, but that most people will do fine with either. Is that assumption correct?

[ALK-O'd]

I am currently wearing an “off the shelf brand” pair of semi-scleral (Blanchard MSD 15.8 mm) lenses that I got from my local OD. I actually just put a detailed post about them over on D’Eyealogues (http://www.lasermyeye.org/forums/showthread.php?t=2695)

For me, I have been very curious about the larger RGPs for a long time since my battered, fragile corneas just can’t take corneal RGPs at all. But, I didn’t want to leap into throwing a small fortune into something that might end up being a total waste. I figured that first trying a commercial brand would at least give me some idea as to whether or not I still had the same kinds of problems with bigger lenses that I was having with the smaller ones. The lenses + fitting only cost me $600 and the overall result has been positive. I do believe there is room for improvement of the fit in one eye though so I may at some point venture out to one of the big league players.

“I think that given the slight differences between Dr G's and BFS sclerals would probably make some patients have better results with Dr G's and some patients will get better results with the BFS, but that most people will do fine with either. Is that assumption correct?”

Generally speaking I would think so. In my opinion, the question of Dr G vs. BSF pertaining to fitting full sized sclerals boils down to a question of technology vs. experience. There actually is one member on this board who has been fitted with sclerals at both BSF and Dr G’s practices and did significantly better with Dr G. Read her thread titled “A Second Chance for Sclerals” over in the Sclerals forum (http://www.dryeyezone.com/talk/showthread.php?t=9170). Of course that is just one individual’s experience. You have to weigh a number of things before deciding between the two. You might want to research if your health insurance would cover BSF’s lenses. There’s a better chance of that then getting Dr G’s covered. Also, no disrespect to Dr G whatsoever but despite the scanning technology he has at his clinic, there is greater overall combined experience with regards to full sized scleral lens fitting and design over at BSF – but you may have to invest a lengthier time period (and potentially a lot more dough) there than you would with Dr G. It might also be worth sending Dr G an e-mail to ask him what percent of his contact lens fittings in general these days are for full sized sclerals. He’s good at responding to e-mails and I’m sure he would tell you – and if you get that info, let us know.

What really would be nice would be if Dr G and the folks at BSF could team up somehow to combine experience AND technology to achieve a scleral lens fitting process that could better guarantee a successful fit in general for all of us.

[texaseyes]

where do you get your information???

As someone who has been through the BFFS experience (unsuccessfully) twice, and had a good experience with Dr. G, I had to reply to this last post, because I believe it is misleading.

1) "Technology vs. Experience": Dr. G has years of experience fitting RGP's, including sclerals. About 90% of the RGP's he fits now are sclerals, according to him. The fact that he got my fit right the first time when I couldn't get a decent fit after 18 lenses in Boston is testimony that he knows what he's doing. He can make sclerals in whatever size is appropriate - mini or full, and that is decided by both YOU and HIM. You are a partner in your choices, and you can see the vault of your cornea with your own eyes on the imaging.

2) Better chance getting BFFS covered by insurance than Dr. G's lenses? NOT TRUE. BFFS takes MEDICAL insurance, Dr. G takes VISION insurance plans. I got my lenses from Dr. G covered by a significant amount by my VISION plan, thanks to the efforts of his staff. Not to mention that his BEFORE insurance price is 75% less than you will pay for BFFS lenses in the first place. Even if your medical insurance covers a percentage of the BFFS lenses and you don't have a vision insurance plan that covers Dr. G's lenses, there is a very good chance you will still pay signficantly more for the Boston Lenses. I know this from personal experience.

3) Dr. G and BFFS teaming up: Are you kidding? BFFS is a big institution that serves the medical needs and research of lots of serious medical conditions. They have a LOT of overhead costs because of their large staff (not just the doctors) and facilities. They also provide lenses to people who cannot pay, and that cost gets passed down to those that can. Certainly, they serve a very important role in ocular rehabilitation.

In contrast, Dr. G is a basically a one man show, along with his relationship with his lab; i.e. very low overhead. He is dependant on only himself for the success of his scleral business. How do you benefit from that? You get lots of generous personal attention, and you get to be a partner in deciding the best lens for you. Of course, I've already complimented his fitting in terms of both technology and skill. Dr. G himself told me that he would love to make his practice 100% sclerals. How is that for commitment to success? What a great opportunity for dry eye patients to take advantage of a technology that can bring relief, good vision and is so much more affordable than originally believed. I almost didn't go through with the lenses with him, because I didn't want to pay more money for more lenses I couldn't wear. He gave me no guarantees, because he is honest. I am SO glad I went ahead with it, because now I have someone that I know is committed to helping me feel and see my best. I hope you will give him a chance and help his practice succeed so that more people can benefit and feel better. Send him and email or give him a call before you make assumptions that you post on this website.

Linda