Aniridia can be congenital or acquired because of trauma or severe intraocular inflammation. Partial or complete aniridia, including missing iris segments, absent or deficient iris pigment epithelium, or complete iris absence, can result from both conditions.1 Patients with aniridia might complain about glare, photophobia, decreased contrast sensitivity, decreased depth of focus, and reduced visual acuity. Those patients might also be dissatisfied because their cosmetic appearance is affected. Various treatment options are available and include colored IOLs and microtying suture techniques that can be used to repair small iris defects. However, in more complex cases with large or complete iris defects, implantable iris prosthetics might be more suitable.
The CUSTOMFLEX ARTIFICIALIRIS (HumanOptics) is a thin, foldable, prosthetic iris made of silicone and is, to date, the only U.S. Food and Drug Administration-approved artificial iris. It has a fixed pupil aperture of 3.35 mm and an overall diameter of 12.8 mm that can be sized with a trephine for each case. The implant is individually custom-made to match the patient's natural iris color, creating an excellent cosmetic effect. The device is available in 2 models, “with fiber” or “fiber free”: the former design allows suturing of the implant, if needed; the latter design does not. A variety of IOLs can be combined with the implant and, if necessary, be sutured directly to it (“sandwich” or “backpack” techniques). The downside, however, is that the artificial iris–IOL package becomes less foldable and its implantation would require a wider incision, resulting in substantial surgically induced astigmatism (SIA). Because aniridia is often associated with significant astigmatic refractive errors, it is essential to keep the SIA low.2 We, therefore, developed a new “slip-and-slide” technique that combines IOL and artificial iris implantation while minimizing the SIA. In this study, we describe 2 cases in which the artificial iris was implanted with this technique, including the first case, to our knowledge, combining a toric IOL with the CUSTOMFLEX ARTIFICIALIRIS.
Case 1: Nontoric IOL
A 79-year-old man diagnosed with posttraumatic complete aniridia and aphakia with rupture of the globe after an accident 3 years ago presented at our clinic for the second time. During repair of the ruptured globe, he underwent globe reconstruction as the first step, followed by vitrectomy due to secondary detachment of the retina. At his first visit, perforating keratoplasty was performed, which left him with a visual acuity of 1.0 logarithm of the minimum angle of resolution (logMAR), intraocular pressure (IOP) of 6 mm Hg, and a refraction of 14.75 −1.25 × 142. At his second visit, a combined implantation of an IOL and an artificial iris using a self-developed new small-incision surgical technique was decided. The procedure is shown in Video 1 (available at http://links.lww.com/JRS/A105). First, the average of the horizontal and vertical white-to-white diameters for proper implant sizing was used. The diameter of the artificial iris was then reduced to 12.0 mm with 2 concave iridectomies at the rim. A monofocal IOL with plate haptics (CT ASPHINA 409M/MP, Carl Zeiss Meditec AG) was sutured on the posterior side of the artificial iris by piercing the 4 haptic edges of the IOL. The sutures went from the posterior direction to the anterior without going back or interlocking the threads. The needle-insertion points were marked with a blue marker pen, and 2 scleral pockets (modified Hoffmann Pockets) at the 3 and 9 o'clock positions were prepared. A 3.0 mm main incision was made, and ophthalmic viscosurgical device was extensively used to protect the endothelial tissue during the delivery and unfolding of the artificial iris. Then, a bent 30-gauge needle was inserted at the temporal markings, and the handshake technique was used to lead the thread through the main incision out of the needle-insertion points. The IOL was then slightly detached from the artificial iris with only having 2 threads (one third for each haptic) holding the package together. The then-detached implant was folded with forceps and implanted through the main incision into the sulcus, with immediate unfolding. The step was repeated with the IOL folded that slipped into the sulcus and slid behind the artificial iris after carefully pulling the strings. The IOL was attached to the iris prosthetic again and centered as planned. Afterward, the same technique was performed as mentioned earlier to lead the nasal threads through their insertion sites. Sutures were tied, and knots were placed within scleral pockets. By pulling the threads carefully to each side, the IOL was centered as planned behind the pupil, and the artificial iris was centered by adjusting the threads through Hoffmann pockets. The conjunctiva over the pockets was closed, the main incision hydrated, and the surgery finalized with a small suture.
Two days postoperatively, the IOP (air) was 6 mm Hg, and 6 months later, distance-corrected visual acuity was 0.7 logMAR with a refraction of 1.25 −1.5 × 130 and an IOP (applanation) of 9 mm Hg. No complications were reported during the follow-up period. The patient was extremely satisfied with the outcomes, including improved visual acuity, reduction of glare and other visually disturbing phenomena, and his esthetic appearance.
Case 2: Toric IOL
A 63-year-old woman with posttraumatic aniridia and aphakia presented at our clinic complaining of reduced visual acuity. After her accident 1 year earlier, she had primary care and pars plana vitrectomy with gas injection. Because of her complaints, an artificial iris implantation in combination with a monofocal toric IOL with plate haptics (AT TORBI 709M, 17.5/2.5 dpt, Carl Zeiss Meditec AG) was planned. The patient's visual acuity was light perception immediately after her accident but recovered to 0.2 logMAR with −11.25 −2.5 × 119 prior to artificial iris implantation. Biometry was performed using an IOLMaster 700 (Carl Zeiss Meditec AG), and corneal regular astigmatism was assessed on corneal topography (Pentacam, Oculus Optikgeräte GmbH).
After white-to-white measurements, the artificial iris diameter was trephined and reduced to 8.5 mm. A concave iridectomy was performed, and the toric IOL was prepared by piercing its accurately (Videos 1 and 2, available at http://links.lww.com/JRS/A105 and http://links.lww.com/JRS/A106) marked haptics, leaving an equilateral triangle with the toric markings presenting the apex of the triangular. A fine thread to mark the IOL center and axis was fixated at those points that present a small hole for IOL rotation in the lens. The IOL was then centrally fixated the same way as mentioned in case 1. Scleral pockets were created at the flat axis, and the same surgical procedure as described earlier was performed. Nonetheless, in this case, it was decided to fold the artificial iris–IOL package and insert it together without detaching it from another to avoid an overcorrection of the toric component. Once inside the sulcus, the IOL got separated slightly from the artificial iris, which was fixed by pulling the strings individually. After final centration, the main incision was closed, the knots were set within the scleral pockets, and the central IOL axis thread was removed. Surgery was finished by suturing the pockets and removing the trocar. The procedure can be seen in Video 2 (available at http://links.lww.com/JRS/A106).
One month postoperatively, IOP (air) was 14 mm Hg, distance-corrected visual acuity was 0.1 logMAR with a refraction of −0.5 −1.0 × 165, and IOP was 11 mm Hg. No postoperative complications were reported. The patient was extremely satisfied with her visual and cosmetic outcomes resulting in significant improved quality of life.
The unique artificial iris prosthesis is a highly versatile implant that offers various options for implantation and surgical techniques.3 The surgical approach, whether it is sector-shaped iris segments and injector-assisted sulcus or capsular bag fixation with or without an IOL, must be decided for each individual case considering their advantages and disadvantages. There have been several reports on artificial iris implantation with combination of IOL implantation. Some of them implanted both separately, whereas others implanted them as an iris–IOL package. For instance, Ayliffe et al. reported microincision IOL and iris prosthetics implantations through the same less than 2.0 mm incision.4 Mayer et al. recommended a sandwich technique of combined iris and IOL implantation whenever possible because it can be performed in a single session despite a larger incision size.3 Spitzer et al. decided to combine both implants while using an incision of 5.0 mm.5 Both, separate or combined techniques, led to good visual and cosmetic outcomes, although larger incisions might induce greater astigmatism.6,7 In traumatic eyes, however, it is essential to keep the incision as small as possible to avoid not only additional SIA but also additional corneal trauma.
We developed a new technique to adhere to the recommendation by Mayer et al. of a combined implantation of iris prosthetic and IOL while targeting an incision size as small as possible. The knotless fixation of the IOL to the posterior surface of the iris implant enables a slight detachment of both components and, therefore, a separate implantation. This way, both parts can be handled and folded as if they were not attached, which enables a small incision. In addition, both implants can be fixed with 1 suture resulting in a reduced conjunctival area of scarring in these traumatized eyes at higher risk for severe glaucoma with the need for filtering surgery. Furthermore, it is quite challenging to have a sufficient distance during implantation to the cornea to prevent corneal endothelial loss, and the surgeon must be particularly cautious during this step. We recommend using a dispersive ophthalmic viscosurgical device to better protect the cornea therefore. Overall, the technique is more complex and demanding than a firm fixation of both implants. However, reducing the incision size from 6.0 or 5.0 mm to 3.0 mm is a major advantage. We were highly satisfied with the surgical procedure and visual outcome and decided to perform it for a second case with a toric IOL.
To the authors’ knowledge, this is the first case describing the implantation of an iris prosthesis combined with a toric IOL. This approach is particularly challenging because the pupil diameter of the artificial iris is fixed at 3.35 mm, making the toric IOL markings invisible and, therefore, proper IOL alignment with the intended axis difficult. Nevertheless, after careful considerations, we decided to perform our new technique with the addition of marking the IOL axis so that it can be seen even with the attached iris implant. We used a toric IOL already provided with small holes at the toric markings, which made it easy to attach a string that went all over the central axis. This string was visible at all times during implantation, whether the IOL was attached or slightly detached from the iris, making the IOL alignment easy. We removed it at the end of the surgery. Our technique with 4-point fixation to the iris implant allowed only for 1 desired position of attachment, which avoided misalignment within the iris–IOL package. Therefore, our technique not only allowed to reduce the incision size in combined iris–IOL package implantation but might also be a solution to properly combine toric IOLs with an artificial iris.
So far, the literature recommends the sandwich technique to combine correction of aphakia and aniridia in a single session.3 However, our new technique offers the advantage of having not only the procedure in a single session but also keeping the SIA at a minimum. Therefore, we find it even more suitable in such traumatic eyes. We used a plate-haptic IOL to exploit a 4-point fixation when attaching it to the iris implant. Because the artificial iris prosthesis and its fixed pupillary diameter offer the best-possible solution regarding glare sensitivity, depth of focus, and contrast sensitivity in addition to the best-available esthetic outcome, we recommend the combination of this device with a plate-haptic IOL for the slip–and-slide technique, possibly with a toric IOL.8
WHAT WAS KNOWN
- The CUSTOMFLEX ARTIFICIALIRIS comes with or without polymer fiber meshwork whether suturing is indicated or not. The fiber also allows for IOLs to be fixed at the implant.
- Esthetic appearance of the iris prosthetic is outstanding, enabling high patient satisfaction.
WHAT THIS PAPER ADDS
- The slip-and-slide technique allows a combined implantation of iris prosthetic and IOL while keeping the incision small and, therefore, the surgically induced astigmatism at a minimum.
- The new technique works with nontoric and toric IOLs and might improve toric correction of traumatized aniridic eyes.
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