What are Intacs for keratoconus?



Intacs is the trademark name for micro-thin implantable intracorneal ring inserts – a procedure used to improve mild myopia, also studied to determine its usefulness in reducing hyperopia, astigmatism and helping improve vision for those with keratoconus.

They are an alternative to laser surgery, and are tiny, crescent-shaped prescription devices made of plastic polymer which is a contact lens-like material (PMMA, also known as ICRS).

How many types are there?

There are three: Intacs, Ferrara and Bisantis. They differ by their size and shape. All are made in segments of Perspex (originally a full 360 degree ring when first developed).The differences are in diameter and shape. Intacs are the largest in diameter, Ferrara in between and Bisantis the smallest. Intacs are hexagonal in cross-section, Ferrara rings are triangular and Bisantis are oval.


Intacs have been used for Keratoconus since around 1999 and were originally FDA approved in 2004, and achieved CE status in Europe and NICE in the UK with some studies lasting more than 10 years, for the treatment of keratoconus. Results of Intacs for keratoconus treatment have been encouraging, especially in patients unable to tolerate contact lenses or in need of a corneal transplant/graft.

In US clinical studies, 97% of patients saw 20/40 or better with Intacs®, 74% saw 20/20 or better, and 53% saw 20/16 or better.

Similarly, in Iran, researchers found Intacs to be a safe and effective treatment option for patients who have keratoconus and contact lens intolerance. In this study, 37 eyes of 36 patients with moderate to severe keratoconus, clear central cornea and contact lens intolerance underwent Intacs placement. Postoperative examinations demonstrated a clinically significant improvement in both uncorrected distance visual acuity and best-corrected distance visual acuity. Both had a continuous improvement throughout the follow-up period – See more at: http://www.revophth.com/content/t/cornea/c/37805/#sthash.yLxanUyy.dpuf

Who is suitable and who is not?

Those with clear central corneas (although some reports of benefits in eyes with small scars), corneal thickness of 0.45mm or more at the insertion site, those with corneas flatter than 57D (best about 53D with a relatively low level of short sight) for Intacs, although the new SK type is designed for levels above this (including over 60D).

The inserts are surgically implanted in the periphery of the cornea at the outer edge of the cornea so that the centre of the cornea remains untouched. They are usually not noticeable and require no maintenance, unlike contact lenses. The effect they have is to flatten the cornea, allowing better focusing and providing crisp vision. Intacs inserts can be removed safely and replaced if a prescription changes. Removal of Intacs causes a patient’s eyes to regress to the condition they were in before insertion in most cases.

Unlike procedures such as LASIK, the insertion of Intacs causes the cornea to generally flatten. In addition, Intacs can decrease the irregular astigmatism found in keratoconus, but Intacs do not generally correct astigmatism, so if you have significant astigmatism they will not correct your vision without you needing to wear a contact or spectacles postoperatively. The primary goal of Intacs in keratoconus is to make the eye tolerant of wearing contact lenses and to avoid corneal transplantation. Other goals are to improve vision with glasses as well as uncorrected vision (without glasses or contact lenses). The goal of Intacs varies with the severity of your problem.

People with post LASIK corneal ectasia may also benefit from having Intacs fitted. Those who should not undergo an Intacs procedure include people who are under 21 years old, pregnant women, people who can still see well with contact lenses, people whose central corneas are not clear, people who have other eye health problems that may cause future problems and  people taking certain medications that may impair healing of the eye.


At the beginning of the procedure, topical numbing eye drops are used. An holder supports your eyelids to stop you blinking during the operation. A channel within the cornea is then prepared, into which the Intacs are inserted. This is done with a laser called an Intralase or with a special intra-corneal tunnelling instrument. Either way a suction ring is placed to stabilise the eye, and the channel is prepared for the Intacs, which are then inserted.

Some patients may have 2 Intacs placed in each eye, others may have only one placed depending on the individual cornea. At the end of the procedure, a stitch or contact lens bandage is placed, more eye drops are given, and a plastic eye shield is offered for short term protection particularly at night. The eye drops used are to avoid infection and inflammation for at least a week and are usually cortisteroids.

Vision can start to improve the day after the procedure but may change for several days. Most people can go back to work a few days after the procedure. During your subsequent check ups, they might look to change the Intacs size or position, or doing other procedures such as CK, and other techniques. Intacs are not necessarily a one off procedure, other treatment might be necessary over time to enhance and optimise the final results.

Can you feel them after they are implanted?

No, although there can be a temporary feeling of ‘stiffness’ associated with nerve damage at insertion. The nerve damage will heal over a period of several weeks.


INTACS Advantages

  •          Can be removed and replaced with new prescription if needed
  •          Improvement in vision occurs for most people within the first day
  •          No tissue removal
  •          No ongoing maintenance, unlike contact lenses
  •          Does not change curvature of cornea, may even flatten it
  •          The patient cannot feel the implants once they are inserted
  •          97 percent of people who have Intacs have driver’s license vision without the need for eyeglasses or contact lenses
  •          Over 50% of people who have Intacs have 20/20 vision or better
  •          Free in the UK on the NHS

INTACS Disadvantages

  •          Not suitable for everyone with keratoconus, especially advanced cases
  •          Risks are involved with the actual procedure, but not more than with any other type of eye surgery. For example, there is a risk of infection, overcorrection, blurry vision, double vision, corneal blood vessels, halos, glare, and fluctuating distance vision.
  •          Surgery does not work on all patients, and new treatment methods may need to be explored.
  •          Expensive; usually not covered by vision insurance plans (USA)


Possible side effects with Intacs

As with all surgery there are many, but most are rare or very rare. Discomfort/ pain up to 48hrs which can be treated with medication, blurred or fluctuating vision and tearing with light sensitivity and dryness. The rings may move and need repositioning. Infection is very rare.

Some may have to be removed after a while (5.0% to 10.0%) and the eye should return fully to how it was before surgery, which was its main attraction in surgery for short sight. Because some patients respond and heal differently, results can vary. In addition, other optical side effects include halos around lights and glare, especially at night.

Intacs with collagen cross linking cxl

Collagen cross-linking (CXL) aims to strengthen a thinning cornea and stop the keratoconus progressing. CXL can be combined with Intacs to further flatten the corneal curvature. The Intacs inserts effectively reverse whatever keratoconus steepening had occurred before the treatment, and the CXL stops it getting worse.

In the USA Holcomb C3-R is used by some doctors which is epi on CXL, followed by Intacs insertion to further improve vision. The European standard (thought to be more effective long term is epi off CXL, and sometimes Intacs are also added before of after the CXL procedure.

Majid Moshirfar, MD, notes that questions remain regarding which procedure should be done first. “For mild keratoconus, especially if a patient is young, I will do collagen cross-linking,” he says. “On the other hand, if the patient is middle-aged and has moderate keratoconus, I will most likely place the Intacs first. Some surgeons are creating the channels for the Intacs with the femtosecond laser or their mechanical system, and then they inject the riboflavin into the channels and then they put the rings in simultaneously,” says Dr. Moshirfar, a professor of ophthalmology at the John A. Moran Eye Center in Salt Lake City, Utah.

A study conducted in Turkey has found that combined Intacs placement and corneal collagen cross-linking treatment with intracorneal riboflavin injection was effective in keratoconic eyes. The study concluded that “intracorneal riboflavin injection into the tunnel was safe and may provide more penetration without epithelial removal.”

This study included 131 eyes in 105 patients with a mean follow-up of 7.07 months. The mean improvement was 0.26 ±0.16 logMAR in uncorrected distance visual acuity and 0.24 ±0.16 logMAR in corrected distance visual acuity.

A recent study conducted in Canada found that the combination of Intacs placement followed by sequential same-day PRK and collagen cross-linking may be a reasonable option for improving visual acuity in some patients with keratoconus.

The study included five eyes in four patients. All eyes first underwent laser-enabled placement of Intacs, followed by same-day PRK and collagen cross-linking. Six months after the procedures, significant improvements were seen with regard to uncorrected and corrected distance visual acuity, spherical equivalent refraction, keratometry and total aberrations. None of the patients lost lines of corrected distance visual acuity or developed haze.

See more at: http://www.revophth.com/content/t/cornea/c/37805/#sthash.1PEPbwHs.dpuf

Intacs are not right for everyone but certainly worth asking about to see if they can help you. To chat to people who have had Intacs join KeratoconusGB on Facebook and Twitter @keratoconusGB 











20 thoughts on “What are Intacs for keratoconus?

  1. Very informative post. The like button is acting up again, so here’s my LIKE. 🙂

    I’m so glad you’re across the pond for another perspective because unless you really do your research over here via the journal articles in PubMed and whatnot, you have no idea what you’re getting into when KC hits. Due to our horrid, for-profit healthcare system in the US, many corneal specialists are running cash businesses via LASIK, PRK, upgraded lenses for cataracts, Intacs, now CXL, and on and on.

    Some employer-based insurances will pick up a percentage of pricey refractive surgery or cover the bulk of Intacs, but you can still pay nearly $10k USD for many of these procedures and as you pointed out, something like Intacs may or may not be needed but the bad doctors will tell you otherwise. I didn’t mean to hijack your blog the other day, but I nearly got into the hands of those bad guys myself and it’s very, very scary as their PR firms show up in online forums and even on blogs selling their wares (often disguised as KCers), and you can’t miss their ads if you Google “keratoconus.” Ugh.

    Oh, why can’t we have nationalized healthcare like you?! Okay, I’ll get off my soapbox now.

    • Thanks for your comments. I’m glad you find the blog interesting and useful. Here in the UK we are amazed what “corneal specialists” are allowed to get away with in the USA. Advertising “cures for Keratoconus” just isn’t allowed. Makes me angry that scared people with kc fall for this and pay $$$$ for treatments that are free or heavily subsidised here.
      We will continue to write unbiased blog posts and share good honest info here and hope that people can learn and share

  2. Thanks for the info and I don’t worry about you because the UK is so different and light years ahead of us, but glad you know about the mess in the States as it’s rather hidden on the websites. It’s like the Wild West out here. :/ Yes, I’m very familiar with that doctor who is referred to by a nickname of sorts online, which is a silly name as there are other corneal specialists where he is due to a very good medical center nearby where he’s NOT on staff. I just Googled the procedure you referred to and that’s him and the same CXL doc your recent poster will be seeing if that was a legit blogger. He also has most of those ads and websites, but he’s not giving people vision back via epi-on CXL, of course (or anything else). If you get bored, do some digging to find out how his most famous KC patient can actually see again–and who knows how well, but it’s not from epi-on CXL, as touted. I’m so glad I didn’t fall for it, but a lot of people do.

    I have to be very careful with what I say because I am in the US and Americans sue, which the rest of the world sort of scratches their head at, but it is true that we live in a highly litigious society. Good riddance! It’s also why I’m rather anonymous on here. I’d prefer to be myself on WP, but can’t as I tell the truth about my experience with the doctors here (my CXL surgeon was fine; it’s the others). I have chosen to not write about the epi-on controversy on my blog due to that, but boy would I like to. When I could still see how the Googlers were getting to my blog, this was a common search term: “epi-on crosslinking and keratoconus is worse.” Scary. Well, thanks for understanding why I get a little feisty!

      • I’m going to attempt to. I don’t have a public email I use, but I made one awhile back that I detest as I can’t figure out how to make it KC friendly or merge it with my Outlook without pulling my whole name, so I never use it or check it. The other issue is it doesn’t seem to work, so just let me know if you don’t hear from me–it’s my blog’s name just so you know.

      • Argh. Okay, I sent it over 24 hrs ago and I tested it to make sure “send” was working and I got my own message in my regular inbox. I just checked to see if “reply” was working and my message went back. I have no idea what the issue is as it is working correctly! Is there a junk box in gmail and did it go there? That seemed to be precisely the problem before: I sent an email and no one got it. I’ll resend and see what happens, but it’s saying it sent the email.

      • I’m so confused! I changed something in the settings I can barely see in that account and sent a new one–I’m not sure what else to do or why I can send emails to my other account. If you feel comfortable, you can leave me a message on an old post and I’ll reply that way and delete everything once I know you’ve gotten my reply (or do I even have to wait???). :/

    • I don’t do any social media so no FB or Twitter. I don’t know why that email won’t work? I got your email sent to the address I use on here, but that’s Outlook and defaults to my primary address and I really don’t want my full name in KC land or anywhere (it won’t reply back with that address you see), which is what will happen if I reply. I’m sorry! I don’t know what to do–I wish I knew how to fix the other account, but I have no idea what’s wrong with it. I think something happened when I tried to forward it to Outlook and as it pulled my full name there, I just forwarded it back and got a glitch. I really am sorry, but doctors over here know my name and I can’t risk it. I’d set up a new account if I could, but now that account is running the android I had to get when my “basic” phone conked out.

      If you can think of anything else, let me know. If not, do you mind deleting this thread past the original comments. I’m so paranoid it’s insane, but I had to block one of those doctors from my e-mail and am still having problems with them. :/

      Oh, I read a long time ago that there was some private comment option with this theme, but never found it and wasn’t interested. I can chat with you there if you can figure that one out, but don’t drive yourself insane in the process.

      • If you got my email and reply to me that’s private? And I’m not in the habit of giving out names etc. Not sure I fully understand why you can’t reply to me, oh well, if you’re not on fb etc that’s that!

      • I’m really sorry and not trying to offend you or make accusations.. I don’t want anyone to have my full name because there are doctors and phony people on WP (I’m not saying you are the latter) and I have to protect my privacy–that’s all. Some people love to be all over the web and others don’t. C’est la vie. I am having issues with a KC doctor as stated and can’t risk it. It’s simply a general policy I have. Again, feel free to leave a comment on an old post if you wish. I don’t do any social media–it’s just something I’m not interested in and as stated in my About section, I only have a blog because my brother created one so I could document my CXL experience since I couldn’t find anything online, or at least anything not written by a marketing firm. I really don’t even like blogging in all honesty. I truly didn’t mean to upset you and am confused myself. I have bigger fish to fry than KC due to my EDS, so life is hard enough and I don’t need anything else on my plate. I hope you can understand.

      • Thanks for understanding. You can refer your FB person to my blog–I have lots of info on there and no problem chatting with them on any post. I mainly talk to EDSers over there, anyway.

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