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Floating surgical technique secures artificial iris
Artificial iris implantation may be a standalone procedure or combined with a procedure such as cataract surgery or corneal transplantation.
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Iris tissue loss due to trauma, iatrogenic cause, or congenital absence such as aniridia or coloboma can result in photophobia, loss of depth perception, contrast sensitivity degradation, glare, decreased visual acuity and multiplopia. In aniridia cases, Wilms tumor should be investigated because the aniridia incidence is one in 70 children with Wilms tumor.
While smaller iris defects can be closed with sutures, large amounts of iris tissue loss often require a cosmetic colored contact lens with a pupil or an artificial iris. None of the cosmetic iris implants are currently approved by the U.S. Food and Drug Administration, and implantation requires receiving a compassionate use exemption. For artificial iris implantation, the patient should be symptomatic and unable to become asymptomatic with tinted glasses or contact lenses. An artificial iris is not to be used for the sole purpose of changing iris color. Types of artificial iris implantation include capsular bag seating, sulcus fixation or attachment to residual iris remnants. Artificial irises are made by HumanOptics, Morcher and Ophtec and consist of either silicone or PMMA material. A silicone artificial iris can be foldable. Intracapsular placement is combined with a capsular tension ring to prevent or minimize potential capsular shrinkage and misalignment and distortion of the implanted artificial iris.
In this column, Dr. Pfeifer describes his surgical method of artificial iris implantation using sutures to prevent or minimize potential intraocular inflammation associated with tissue rubbing and secondary macular edema. Further investigation with a larger patient population, longer follow-up and continued monitoring of artificial iris patients are required for a more complete assessment of the overall long-term outcomes of this patient population.
Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor
Vladimir Pfeifer
Artificial iris implantation has been associated with recurrent iritis due to the physical contact with recipient ocular tissues and may result in secondary cystoid macular edema and blurred vision in some patients. In an attempt to obviate such inflammatory occurrence associated with an artificial iris, I developed a surgical technique of implanting an artificial iris with suture suspension from the sclera that prevents any rubbing of this prosthetic device with the patient’s intraocular tissues, thus eliminating secondary macular edema in such cases (Figures 1 to 11). This is called the floating surgical technique of an artificial iris. Figure 11. A clear corneal graft and a well-centered artificial iris are seen with no cystoid macular edema 12 months after surgery.
Figure 1. The artificial iris is secured with a lasso knot, the needle is passed through the MVR incision out of the sclera, and sutures are tied to the scleral outer wall using a Z-suture technique.
Figure 2.The artificial iris is floating in the aqueous, tied to the sulcus with four 9-0 polypropylene sutures without touching any intraocular structures, thus avoiding inflammation.
Figure 3. There is enough space between the artificial iris and intraocular tissues to prevent any touch between the implanted device and recipient ocular structures.
Figure 4. After the cataract was removed and the IOL implanted into the capsular bag, the needle of 9-0 polypropylene suture is docked into the 25-gauge cannula and brought through an MVR blade incision out of the sclera, 2 mm behind the limbus.
Images: Pfeifer V
Figure 5. The artificial iris has been trimmed to 9.5 mm. Four lasso knots were placed around the artificial iris, 90° apart. Two leading sutures were passed through MVR blade incisions. The artificial iris was folded and implanted through a 3-mm main incision.
Figure 6. The artificial iris was unfolded by pulling on the leading sutures and then pushed under the patient’s iris remnants. The trailing needles were passed through remaining MVR blade incisions. Using the Z-suture technique, the artificial iris was centered and fixed to the sclera.
Figure 7. Six months after surgery, best corrected visual acuity is 0.6, and the artificial iris is well centered. There is no inflammation, and good cosmetic appearance is seen.
Figure 8. In case of a combined procedure, the IOL is first sutured to the artificial iris and then implanted through the corneal opening.
The artificial iris is floating in the aqueous, held in position with four sutures tied to the sclera (Figures 1 and 2). The sutures are passed through the artificial iris and then through the sclera, 2 mm behind the limbus, and are then tied to the sclera using the Z-suture technique. Such a surgical technique results in the artificial iris coming into contact only with the sutures used for artificial iris suspension. The artificial iris is trimmed to size according to the requirements of the individual eye and sutured with four 9-0 polypropylene sutures. Artificial iris implantation may be carried out as a standalone procedure or combined with other surgical procedures such as cataract surgery or corneal transplantation.
Surgical procedure
In combined cataract surgery with an artificial iris, the cataract is removed and the IOL is implanted within the intact capsular bag. The artificial iris is then trimmed to the appropriate size and fixated in place using special looped polypropylene sutures. The sutures are tied to the artificial iris using the lasso technique (Figures 1 to 3). After perilimbal scleral exposures using sharp and blunt dissection, four incisions are made in the sclera, located 2 mm from the limbus using a 20-gauge MVR blade. Two needles are passed through the main incision and docked into the 25-gauge cannulas that are introduced into the anterior chamber through the scleral incisions (Figure 4). The needles and the sutures are then externalized by exiting through the scleral incisions. The artificial iris is folded on itself, introduced into the recipient anterior chamber and unfolded within the anterior chamber (Figures 5 and 6). The two trailing sutures are brought into the anterior chamber through the main cataract incision, docked into the cannulas and brought out via the two remaining scleral incisions. The artificial iris is centered appropriately by adjusting the sutures. Using the Z-suture technique, the sutures are fixed to the sclera, and the knot is tied and buried within the sclera. The scleral incisions are closed, and the sclera is covered with the adjacent conjunctival tissue. Figure 7 shows a well-centered artificial iris with no inflammation and good cosmetic appearance 6 months after the procedure.
Figure 9. The IOL artificial iris complex is centered by pulling the four 9-0 polypropylene sutures and secured to the sclera using the Z-suture technique.
Figure 10. The corneal donor button is sutured to the host cornea, and the artificial iris is tied to the sclera. By adjusting the Z-sutures, the pupil is centered.
Figure 11. A clear corneal graft and a well-centered artificial iris are seen with no cystoid macular edema 12 months after surgery.
In aphakic eyes, a foldable IOL can be sutured to the artificial iris using the same sutures. This complex, consisting of the artificial iris and the attached IOL, is implanted into the anterior chamber through the main incision. In cases in which penetrating keratoplasty is performed, an open-sky approach is used to suture the artificial iris, and the donor cornea is sutured in place (Figures 8 to 11). Figure 11 shows the clinical appearance 1 year after surgery with a clear corneal graft, a well-centered artificial iris, no macular edema and a happy patient.
References:
Forlini C, et al. Graefes Arch Clin Exp Ophthalmol. 2013;doi:10.1007/s00417-013-2402-8.Grzybowski A, et al. Graefes Arch Clin Exp Ophthalmol. 2013;doi:10.1007/s00417-013-2401-9.
Koch KR, et al. J Cataract Refract Surg. 2014;doi:10.1016/j.jcrs.2013.08.051.
Rosenthal KJ, et al. J Refract Surg. 2013;doi:10.3928/1081597X-20130919-01.
For more information:
Vladimir Pfeifer, MD, can be reached at oefpv@icloud.com.Edited by Thomas “TJ” John, MD, a clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at 708-429-2223; email: tjcornea@gmail.com.
Disclosure: Pfeifer and John have no relevant financial disclosures.