This article is more than 5 years old. Information may no longer be current.
Femtosecond laser-assisted corneal tattooing easily, effectively masks iris defects
The ink is delivered through a custom pocket, using software for intracorneal ring segments.
Click Here to Manage Email Alerts
A femtosecond laser-assisted technique of corneal tattooing effectively covers up iris defects, eliminating the problems that derive from abnormal light penetration and giving the eye a better cosmetic appearance.
“Patients with iris defect typically suffer from glare, light sensitivity and sometimes double vision because a second hole in the iris creates a second pupil and a ghost image,” Keith Walter, MD, told Ocular Surgery News.
He spoke about three causes of iris defect, the first of which is eye trauma and the second, which is even more common, is cataract surgery.
“I see a lot of temporal iris defects from cataract surgery due to iris prolapse through the temporal wound in cases of intraoperative floppy iris syndrome. Patients have issues with transillumination defects or iris atrophy in that area, over the edge of the lens and edge glare,” Walter said.
The third cause is peripheral iridotomy, performed to treat angle-closure glaucoma or to prevent pupillary block following ICL (STAAR Surgical) implantation. Walter has had about 25 patients seeking his help for this reason. Physicians tend to ignore patients’ complaints, assuming that a little hole that does not interfere with vision should not create problems.
“It takes very little tattooing to cover that hole, and there is 100% satisfaction,” he said. “Peripheral iridotomies cannot be sutured, and even if you could, you would defeat the purpose of the hole, which is to allow fluid to flow back and forth between anterior and posterior chamber.”
Femtosecond technology and artist skills
Source: Keith Walter, MD
Corneal tattooing has been around as a technique for more than 100 years and is traditionally performed by hand poking the cornea with a needle previously dipped into tattoo pigments. The procedure, however, is long and painstaking. Some years ago, Walter created a new procedure, using a femtosecond laser with the Intacs (Addition Technology) implantation software. A round channel is created, typically 5 mm to 9.5 mm long and about 250 µm deep into the cornea, with a peripheral slit that is used to deliver the ink. He purchases the ink from a company called Permark, which produces the devices and pigments for medical micropigmentation procedures such as breast reconstruction.
“I put the ink in the channel, and if it is only a small area that needs tattooing, such as a temporal iris defect from floppy iris syndrome, I only open up about 50° or 60°, just enough to cover it. In case of traumatic wounds, when a large part of the iris is missing, I put in the ink on 360°, and for that I use the Intacs metal blades, going clockwise and anticlockwise to cover the 360° area. The ink is not injected but delivered and spread into the channel by the blades, previously dipped into the pigment, because there are a lot of tissue bridges that need to be opened up in order to put the ink in where it is needed,” Walter said.
Mimicking the iris requires skillful use of colors, something that Walter, as an artist, is familiar with. He explained that if blue ink is put into a blue eye, it will look too blue and bright. The perfect match for blue eyes is gray because a blue iris is in fact gray and the cornea makes it look blue.
“It is not easy to match the iris. Sometimes if you just put in one color it looks flat and unrealistic, so I put in a second color over gray, like a little navy blue by hand, with a needle. I puncture it in different spots to give a little contrast and make it look real. If you paint an apple, it is not just red — it is red and brown, with a little bit of yellow, and reflex is white. Artists know this. Nothing you see is one color. It is all tones and shades, so this is the same idea. You put in the basic color just to block the light from getting into the iris, and then you can perfect the color by putting in little shades of different colors to make it more realistic,” he said.
Thanks to its ring shape and 4 mm to 4.5 mm width, the ring channel is able to cover most defects. The parts that remain outside can be poked by hand using a 30-gauge needle.
The simplest thing to do
Walter initially presented his femtosecond laser tattooing technique at the Kiawah Eye meeting in 2013. Since then, many patients from across the U.S. have contacted and visited him to have the procedure performed. It is a fairly easy and minimally invasive way of fixing an excruciating problem, significantly improving the lives of patients.
The alternatives are less simple. Iris prostheses are not FDA approved and hard to come by, and the other option is going back to the OR so the iris can be stitched.
“It is difficult to do. Some of the patients had their iris stitched, and then it pulled through over the years and then you have to get it re-stitched,” Walter said.
Corneal tattooing is the simplest thing to do, and in some cases, such as covering the hole performed for ICL implantation or glaucoma, it is the only option.
The colors over time might dull slightly, but the cosmetic effect is usually good and stable. In one case, performed by one of Walter’s colleagues, a blue tattoo turned brown, probably due to oxidation or rusting. The original color was easily refreshed with a little more ink on the site, and it was an isolated case, one in about 200 over 6 years.
The technique is not meant for purely cosmetic purposes, Walter said.
“Patients who aim at changing the color of the iris would want a smaller pupil than I think it’s wise. You should not make the pupil smaller than 5 mm, and in bright light, the original color would show up. You see this sometimes with colored contact lenses. In addition, the channel is 9.5 mm, so there is a lot that you would have to do by hand in those cases. It is not a reversible procedure. It is permanent and is meant to be so in the patients I treat, who need to block out the light and glare to see better. Cosmetically the effect is good but not perfect, but still well accepted by these patients who are happy with an imperfect match because what they want is to have the light go away,” Walter said. – by Michela Cimberle
- For more information:
- Keith Walter, MD, can be reached at Wake Forest University Eye Center, 4030 Windsor Place Drive, Winston-Salem, NC 27106; email: kwalter@wakehealth.edu.
Disclosure: Walter reports no relevant financial disclosures.