All About Artificial Iris Implant

Introduction

The iris (colored part of the eye) resembles a diaphragm with a central opening called the pupil. An artificial iris, or iris prosthesis, is used when the iris is partially or completely damaged. This can happen due to injury, multiple surgeries, or even complications in the front part of the eye, or a condition like congenital aniridia (where the iris does not develop). These artificial irises are round, can be made to match the color of the other eye, and are placed in the front part of the eye where the natural iris would normally be. They are attached to parts left behind from previous eye surgeries, such as the capsule or intraocular lens. Sometimes, no stitches are needed, but the prosthesis can be sewn into place using non-absorbable stitches in the eye's outer wall if necessary.

What Is Iris Implant?

An iris implant is a specialized medical device to fix problems with the iris or pupil. This artificial iris implant is for treating conditions like aniridia (missing iris) or damage from injuries to the iris and is customized to match the patient’s eye color and details. It can be inserted through a minor surgical cut in the eye or during the cataract or lens surgery procedure. It is also made from medical-grade silicone since it is safe and does not cause any reactions to the eye.

The natural pupil controls the amount of light that can enter the eye, but people with damaged pupils or irises might experience issues like glare, light sensitivity (photophobia), starbursts, or halos in bright light and might feel self-conscious about the look of their eyes. They may also experience double vision due to light passing through iris defects and hitting the lens unevenly.

Before the artificial iris became prevalent, people wore eye patches, dark sunglasses, or blackout contact lenses as there were limited solutions for the condition. However, the implant is useful both functionally and esthetically. For younger patients under 40 to 50, repairing iris problems such as coloboma (a gap in the iris) is usually better corrected by stitching the iris tissue directly instead of using an implant.

What Is the Procedure for an Artificial Iris Implant?

• The artificial iris surgery is done under local or general anesthesia, depending on the patient’s needs.

• Surgeons make a small opening, about 3.5 to 4 mm (millimeter) wide. It is folded (as the prosthetic iris is usually foldable), placed in a cartridge, and then inserted into the eye’s front chamber (anterior chamber).

• Once placed inside, it is positioned onto the sulcus (a space in the eye) and secured with sutures to hold the prosthetic iris in place.

• In cases where the patient has a corneal transplant (keratoplasty) simultaneously, the implant can be inserted through the opening made for that procedure, making it easier to place the artificial iris in the front chamber.

• The outcomes are generally positive, with a good cosmetic result. Doctors take pictures of the healthy eye to match the artificial iris with the patient’s other eye. A wide variety of colors are available to ensure a close match.

• Since the artificial iris is seated inside the eye, it must be carefully positioned to prevent it from irritating the sensitive internal structures.

• If it rubs against the ciliary body (the part of the eye that controls the lens shape), it can lead to inflammation, which could again lead to complications such as increased eye pressure or even secondary glaucoma.

• These surgeries are usually part of a more complex procedure, so patients need close monitoring afterward. Doctors carefully check the condition of the eye’s front structures during recovery to prevent complications.

What Are the Challenging Yet Rewarding Effects of Artificial Iris?

For the past decade, surgeons from the United States have occasionally used artificial iris implants under special protocols. However, after the FDA (Food and Drug Administration) approved the artificial iris in 2018, it has become more accessible to surgeons around the globe. Even though the artificial iris implant procedure is effective, it is complex and requires special training before a surgeon is qualified to perform it.

Difficult Cases:

Patients needing an iris prosthesis often have serious eye problems, which include:

• Those born without an iris (congenital aniridia) or those who lost their iris due to severe injury. These patients often have other eye issues like corneal damage, glaucoma, retinal detachment, or missing lenses.

• For those with acquired aniridia (loss of the iris after injury), significant damage to the front part of the eye usually remains even after initial surgical repairs.

Contraindications of Artificial Iris Implants:

• The artificial iris cannot be implanted in an eye with a clear lens (phakic eye) since it does not open or close like a real pupil. This means surgeons need to wait until a cataract forms and then perform lens replacement surgery along with the iris implant.

• In rare cases, the procedure could cause cataracts.

• The implant is not suitable for pregnant women, children under three, or patients with certain conditions like severe uveitis or proliferative diabetic retinopathy.

A Custom-Made Solution:

The artificial iris comes in two models:

• With Fiber: This version has a polyester mesh that allows it to be stitched to the remaining iris tissue, the eye’s outer wall, or the lens.

• Fiber-Free: Made of flexible silicone, this version is typically placed in the eye’s capsular bag or sulcus space. It can also be stitched but is preferred when the surgeon can place it securely without stitches.

The artificial iris is custom-made to match the patient’s other eye or, for congenital cases, matched to a family member’s eye. It is designed to have a great look in natural light because if any slight imperfections are found with lighter-colored eyes, it will be very obvious compared to darker eyes.

Surgical Details:

There are three key questions surgeons must address:

• Where will the implant go? It can be placed in the capsular bag or behind the natural iris.

• How will it be secured? Surgeons can let the implant sit passively in place or stitch it to the eye’s remaining tissue or lens.

• How will the implant be inserted? Depending on the patient's condition, it can be inserted with a large injector or a forceps.

Conclusion

The artificial iris is custom-made to match the patient’s original iris, using a flexible material that can be inserted through small incisions. It can be placed in different parts of the eye and works with most lens implants. It helps control light, reduce glare, and improve vision. Made from biocompatible silicone, it has been safely used for over 20 years.