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Retinal Physician

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A Primer for the Vitreoretinal Surgeon on the Customflex Iris Prosthesis

Add this procedure to your surgical armamentarium.

By: Christopher D. Riemann, MD, and, Nathaniel C. Riemann
Retinal Physician September 1, 2021 Vol 18, Issue September 2021 Page(s): 33-36

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The Customflex Artificial Iris Prosthesis (CFIP; Humanoptics) was approved by the FDA in May 2018 as the first standalone prosthetic iris in the United States. It is a surgically implanted device for the treatment of full or partial aniridia. These conditions often present to the retina specialist, and adding this novel capability to the surgical armamentarium makes sense for many retinal surgeons. Retina specialists will likely implant a significant minority of these devices across the United States in the future.

THE ARTIFICIAL IRIS

The CFIP is a flexible silicone annulus 12.8 mm in diameter with a fixed 3.35-mm aperture that corresponds to an observed 4.0-mm entrance pupil due to corneal magnification. The device has a matte black posterior surface and a textured anterior surface. The anterior surface is hand painted based on an index photograph of the patient’s healthy contralateral eye to optimize cosmesis. The CFIP comes in 2 versions — one with an embedded fiber mesh more suited for sutured applications and a no-mesh version for “in the bag” placement, usually in the setting of concurrent cataract surgery (Figure 1).

Figure 1. Dimensions and form factor of the Customflex Artificial Iris Prosthesis (CFIP; Humanoptics).
Figure 1. Dimensions and form factor of the Customflex Artificial Iris Prosthesis (CFIP; Humanoptics).

INDICATIONS

The CFIP is indicated for use in children and adults for the treatment of full or partial aniridia resulting from congenital aniridia, acquired iris defects, or other conditions associated with full or partial aniridia.1 Although some of these devices are placed in patients with congenital aniridia during primary cataract surgery, a majority of CFIP are placed in patients with posttraumatic, iatrogenic, or inflammatory iris injury. These patients often present to the retinal surgeon with associated anterior–posterior segment pathologies.

The posttraumatic patient — after open-globe repair, severe blunt trauma, iris tumor excision, or complications during anterior-segment or posterior-segment surgery — often needs multiple procedures to achieve maximal medical improvement2 that might include pars plana vitrectomy, retinal detachment repair, cyclodialysis cleft repair, epiretinal membrane peeling, epiciliary membrane peeling, pars plana tube shunt placement, pars-plana lensectomy, IOL reposition or exchange, and iris repair. These patients often have symptomatic iris defects not amenable to simple suture-based repair for which concurrent placement of a CFIP may be indicated, sometimes in conjunction with placement of a scleral-sutured posterior-chamber IOL.

A damaged native iris inadequately controls light entry into the eye, and patients complain of reduced visual acuity, glare, halos, dysphotopsias, monocular diplopia, light sensitivity, and pain. Although some visually significant iris defects are obvious, other symptomatic and visually significant iris defects are only apparent on retroillumination where large iris pigment epithelial defects are revealed (Figure 2). A careful history and review of systems and symptoms related to iris defects often elicits a very energetic response from an affected patient.3,4

Figure 2. Retroillumination reveals a visually significant iris defect in a patient with disabling glare (A). The iris defect is alleviated by a suture-fixated CFIP behind the native iris (B). Photos courtesy of VEO Ophthalmics
Figure 2. Retroillumination reveals a visually significant iris defect in a patient with disabling glare (A). The iris defect is alleviated by a suture-fixated CFIP behind the native iris (B). Photos courtesy of VEO Ophthalmics

Advantages of a physiologically sized entrance pupil include improved depth of field and the physiologic collimation of light, which may decrease the effect of irregular corneal optical aberrations (from corneal sutures after open globe repair, for example) in addition to higher order optical aberrations from light entering the eye through the far peripheral, optically less optimized cornea in photopic conditions.

ALTERNATIVES TO AN IRIS PROSTHESIS

Before approval of the CFIP, the options available to patients with symptomatic iris defects were limited. Suture-based iris repair using McCannel and or Siepser knots can effectively repair small iris defects.5 For example, some surgeons routinely close larger inferior peripheral iridotomies when removing silicone oil in eyes with good visual potential. Sometimes intraocular forceps can be used to tease posteriorly retracted iris tissue centrally and anteriorly and an iris cerclage suture can restore a reasonable entry pupil.6 Unfortunately, these techniques are technically challenging and may not yield durable or acceptable results from the standpoints of symptom relief or cosmesis for anything but small iris defects.7

The Humanoptics CFIP is the only FDA-approved iris implant available in the United States. Iris prostheses were previously available and approved in Germany and the Netherlands8,9 and are currently available in Russia, but these products are not FDA approved.

Corneal tattooing, corneal stromal implants, and colored contact lenses have also been described to treat symptomatic iris defects, but these have significant side effects including peripheral visual field loss, unacceptable reductions in the ability to examine the peripheral retina (both due to the aperture being much farther forward from the nodal point of the eye), unsatisfactory cosmesis, and complications, such as corneal scarring and infection.2

CONTRAINDICATIONS

The CFIP is meant to treat visually significant iris defects and restore ocular function. While excellent cosmetic results are an added bonus and help to improve cosmesis in the setting of restoring function, the CFIP is absolutely contraindicated for cosmetic iris color change or any application calling for placement in the anterior chamber.

The Brighteyes (Stellar Devices) and Newcoloriris (Kahn Medical Devices) are not approved in the United States or in Europe, but they are advertised for cosmetic eye color change. These have been implanted outside the United States, leading to multiple associated reports of catastrophic complications requiring explanation and corneal transplant surgery. Unfortunately, this unethical and dangerous procedure continues to be offered outside the United States and Europe10-13 and is not related to the CFIP.14

The CFIP is also contraindicated in patients with uncontrolled uveitis, severe chronic uveitis, microphthalmos, untreated retinal detachment, untreated chronic glaucoma, rubella cataract, rubeosis of the iris, proliferative diabetic retinopathy, Stargardt retinopathy, pregnancy in women, and intraocular infections. Caution should be exercised in patients with glaucoma and in patients with corneal endothelial disease. The device is FDA approved for use in patients 3 years of age and older.

IMPLANTATION

The CFIP can be implanted using 3 different approaches:

  1. In-the-bag placement with cataract surgery. Patients with symptomatic cataract and concurrent symptomatic iris defects can undergo cataract surgery with simultaneous “in-the-bag” placement of the IOL and CFIP. This surgical approach is usually performed by anterior-segment colleagues who specialize in complex cataract surgery and anterior-segment reconstruction procedures. The “without fiber” version of the CFIP is typically used in conjunction with a capsular tension ring. Common clinical scenarios include the following:
    • Ocular albinism;15
    • Congenital aniridia;16
    • Anterior segment trauma; and
    • Eyes with cataract and iris defects after pressure spikes from angle closure, complex glaucoma or vitreoretinal surgery, or uveitis, including herpetic eye disease.
  2. In the sulcus without sutures. In rare instances, the CFIP can be passively placed into the ciliary sulcus without suture fixation. This can be a bit tricky because it is only appropriate in patients where the ciliary sulcus is precisely the right size to accommodate the 12.8-mm CFIP without decentration of the implant. In small eyes, the CFIP can be trephined to a smaller diameter but this requires very careful attention to precisely ascertain the dimensions of the ciliary sulcus using specialized instruments such as an intraocular ruler and the CFIP trephine. This surgical application is uncommon and also mostly reserved for the anterior segment surgeon. The “without fiber” version of the CFIP is typically used.
  3. In the sulcus with suture fixation. This approach is the most common for vitreoretinal surgeons and typically employs the “with fiber device,” which may be more resistant to cheese-wiring. The CFIP is often placed in conjunction with a secondary scleral sutured PCIOL. Common scenarios include the following:
    • Reconstruction after complicated cataract surgery with a luxed intraocular lens (IOL) and iris damage, especially in patients with idiopathic floppy iris syndrome.17
    • Anterior-posterior reconstruction procedures in multiply operated aphakic retinal detachment eyes often with pars plana vitrectomy and membrane peeling or silicone oil removal.
    • Anterior-posterior reconstruction procedures after penetrating or blunt trauma sometimes with pars plana tube shunt placement, or pars plana vitrectomy and membrane peeling.

THE RIGHT SURGEON FOR IMPLANTATION

Clinical scenarios where the CFIP is indicated are often diagnostically and surgically complex and outright difficult. These are challenging cases that are best managed by experienced and broadly capable anterior-segment and posterior-segment surgeons (or both in tandem performing a combined surgery) with diverse and highly developed surgical skill sets. An efficient, nonplussed, and logical approach to intraoperative problem solving that draws on a large “toolbelt” of surgical tricks is highly recommended for consistent excellent results without complications.

Syndromic eyes with congenital aniridia for example, often have severe zonulopathy and abnormally thin lens capsule, which makes “routine” cataract surgery anything but routine. Posttraumatic or iatrogenically injured, multiply operated eyes may present with unpredictable ocular anatomy that complicates surgical maneuvers. Conjunctival scarring or recession, corneal opacity, anterior segment fibrosis, unstable IOLs, scleromalacia, glaucoma, angle recession, cyclodialysis clefts, epiciliary membranes, retinal detachment, proliferative vitreoretinopathy, fibrovascular ingrowth, epithelial downgrowth, hypotony, and choroidal detachments are just a few unpleasant comorbidities that may complicate surgical interventions, even if they seem straightforward. The vitreoretinal clinic typically has a high pathology density of advanced or severe disease, and the vitreoretinal surgeon’s skillset is often uniquely suited to best manage the complex and challenging clinical scenarios that often accompany the clinical need for a CFIP.

PERFORMING PPV THROUGH THE CFIP

The 4-mm entrance pupil is sufficient for uncompromised visualization of the posterior segment. With modern direct contact lenses, wide-angle viewing systems, and good surgical technique, posterior-segment interventions can be performed on the central and peripheral retina with precision. When ocular comorbidity includes corneal or other media opacity, ancillary viewing with an ophthalmic endoscope may be beneficial.18

CFIP IN THE RETINA CLINIC

The population of complex patients that may be candidates for a CFIP need extra time and care in the clinic. It’s best to segregate these patients into a more protected clinic apart from routine injection visits, postoperative visits, or more straightforward consults. These patients should be treated in the same way as patients with uveitis, gene therapy IRD, or complex second opinion consults.

CERTIFICATION

In the United States, the CFIP is distributed by VEO Ophthalmics. Surgeons must complete a comprehensive training program to become credentialed as an implanting surgeon. An online training module is followed by a self-administered “dry lab” in the surgeon’s own operating room with the surgeon’s own staff, surgical equipment, and instruments.

TIPS AND TRICKS

Each CFIP procedure is unique and challenging because it entails diverse surgical maneuvers and intraoperative problem solving, which are well within the skillset of any experienced vitreoretinal surgeon. Limiting the discussion to the particular scenario of a scleral fixated CFIP placed in conjunction with a scleral suture fixated PCIOL yields some useful insight into the nuances of these rewarding surgeries (Figure 3).

Figure 3. Near-complete aniridia in the left eye (A), an endothelial keratoplasty, a phacoemulsification burn with scleromalacia, and an over-tightly sutured Akreos intraocular lens (IOL; Baursch + Lomb) (B) yield counting-fingers vision in this multiply operated eye after cataract surgery complicated by intraoperative floppy iris syndrome. An epiretinal membrane is present posteriorly. A pars plana vitrectomy and epiretinal membrane peel are performed (C). A 7.0-mm scleral tunnel is created (D). Four sclerotomies are created and CV-8 Gore-Tex suture loops are passed into the eye (E). The Akreos IOL is removed. The suture loops are externalized though the main IOL wound and attached via girth-hitch knots to the haptics of an Alcon CZ70BD IOL (F). The IOL is in position and the sutures have been tied (G). The “with fiber” Customflex Artificial Iris Prosthesis (CFIP; Humanoptics) is folded in half (H) with a Nugent forceps, and Gore-Tex sutures are affixed (I). The sutures are passed through the sclerotomies, and the CFIP is refolded and placed into the anterior chamber (J). The intraocular lens–CFIP wound is closed with 10-0 nylon, the sutures are tied, and 1 of 2 suture knots is rotated into the eye. The remaining Gore-Tex knot is rotated into the eye, an air–fluid exchange is performed, and Tenon’s capsule and the conjunctiva are closed (K). The postoperative visual acuity result is 20/70, with no glare and excellent cosmesis (L).
Figure 3. Near-complete aniridia in the left eye (A), an endothelial keratoplasty, a phacoemulsification burn with scleromalacia, and an over-tightly sutured Akreos intraocular lens (IOL; Baursch + Lomb) (B) yield counting-fingers vision in this multiply operated eye after cataract surgery complicated by intraoperative floppy iris syndrome. An epiretinal membrane is present posteriorly. A pars plana vitrectomy and epiretinal membrane peel are performed (C). A 7.0-mm scleral tunnel is created (D). Four sclerotomies are created and CV-8 Gore-Tex suture loops are passed into the eye (E). The Akreos IOL is removed. The suture loops are externalized though the main IOL wound and attached via girth-hitch knots to the haptics of an Alcon CZ70BD IOL (F). The IOL is in position and the sutures have been tied (G). The “with fiber” Customflex Artificial Iris Prosthesis (CFIP; Humanoptics) is folded in half (H) with a Nugent forceps, and Gore-Tex sutures are affixed (I). The sutures are passed through the sclerotomies, and the CFIP is refolded and placed into the anterior chamber (J). The intraocular lens–CFIP wound is closed with 10-0 nylon, the sutures are tied, and 1 of 2 suture knots is rotated into the eye. The remaining Gore-Tex knot is rotated into the eye, an air–fluid exchange is performed, and Tenon’s capsule and the conjunctiva are closed (K). The postoperative visual acuity result is 20/70, with no glare and excellent cosmesis (L).
  • The IOL is typically suture fixated after a pars-plana vitrectomy and any other posterior work (removal of vitreous hemorrhage or membrane peeling, for example) are completed.
  • Gore-Tex CV-8 suture (W.L. Gore & Associates) is strong, has excellent biocompatibility, does not suffer the late breakage reported with 10-0 or 9-0 Prolene suture fixation of IOLs, and is ideal for suture fixation of intraocular implants.
  • Two sclerotomy pairs are created 1 to 2 clock hours apart 180 degrees away from each other in the iris plane, ab-externo into the ciliary sulcus.
  • It can be helpful to suture fixate the single-piece 7.0-mm PMMA Alcon CZ70BD IOL and use a girth hitch knot that straddles the haptic eyelets.
  • The acrylic Bausch + Lomb Akreos (hydrophilic) IOL and Envista MX60 (hydrophobic) IOLs can also be used and require a smaller 3.0-mm wound that can be in clear cornea. The Yamane or other intrascleral haptic techniques may also be used, with care, to place a Zeiss Lucia or Abbott Laboratories AR40 or Z9003 IOL.
  • Once the IOL is in position, a second set of 2 Gore-Tex sutures are fixated to the “with-fiber” CFIP by taking a 2.0-mm bite of the iris device 180° apart and, importantly, the same sclerotomies used for the IOL are recycled for the CFIP suture strands.
  • The sutures are tied, all knots are rotated into the eye, and conjunctiva and Tenon’s capsule are closed.

CONCLUSIONS

Implantation of the CFIP can be very rewarding for the vitreoretinal surgeon. Rising to meet a complex surgical challenge yields superb functional results, excellent cosmesis, and happy, grateful patients. RP

Christopher D. Riemann, MD, is the director of the Vitreoretinal Fellowship and member of the Clinical Governance Board at the Cincinnati Eye Institute in Cincinnati, Ohio, and ophthalmology section leader at Bethesda North Hospital in Montgomery, Ohio. Nathaniel C. Riemann is a biomedical engineering student at Johns Hopkins University in Baltimore, Maryland. Dr. Riemann reports that he is the owner and cofounder of VEO Ophthalmics and a consultant to Humanoptics. Nathaniel Riemann reports no relevant disclosures. Reach Dr. Riemann at criemann@cvphealth.com. Editor’s note: Listen to a discussion of this article on the Retina Podcast at www.retinapodcast.com .

REFERENCES

  1. FDA approves first artificial iris. News release. May 30, 2018. Accessed July 2, 2021. https://www.fda.gov/news-events/press-announcements/fda-approves-first-artificial-iris
  2. Snyder ME, Osher RH, Wladecki TM, Perez MA, Augsburger JJ, Corrêa Z. Results in Combined Cataract Surgery With Prosthetic Iris Implantation in Patients With Previous Iridocyclectomy for Iris Melanoma. Am J Ophthalmol. 2017;175:45-51. doi:10.1016/j.ajo.2016.11.013
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  5. Snyder ME, Perez MA. Iris stromal imbrication oversewing for pigment epithelial defects. Br J Ophthalmol. 2015;99(1):5-6. doi:10.1136/bjophthalmol-2013-304437
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  7. Lian RR, Siepser SB, Afshari NA. Iris reconstruction suturing techniques. Curr Opin Ophthalmol. 2020;31(1):43-49. doi:10.1097/ICU.0000000000000628
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  10. Garcia-Pous M, Udaondo P, Garcia-Delpech S, Salom D, Díaz-Llopis M. Acute endothelial failure after cosmetic iris implants (NewIris®). Clin Ophthalmol. 2011;5:721-723. doi:10.2147/OPTH.S18569
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  12. Galvis V, Tello A, Corrales MI. Postoperative results of cosmetic iris implants [published correction appears in J Cataract Refract Surg. 2021 May 1;47(5):685]. J Cataract Refract Surg. 2016;42(10):1518-1526. doi:10.1016/j.jcrs.2016.08.013
  13. Mansour AM, Ahmed II, Eadie B, et al. Iritis, glaucoma and corneal decompensation associated with BrightOcular cosmetic iris implant. Br J Ophthalmol. 2016;100(8):1098-1101. doi:10.1136/bjophthalmol-2015-307295
  14. Snyder ME, Miller KM, Price F Jr, et al. Preventing confusion between iris color-changing implants and therapeutic iris prostheses. J Cataract Refract Surg. 2020;46(5):804-805. doi:10.1097/j.jcrs.0000000000000170
  15. Karatza EC, Burk SE, Snyder ME, Osher RH. Outcomes of prosthetic iris implantation in patients with albinism. J Cataract Refract Surg. 2007;33(10):1763-1769. doi:10.1016/j.jcrs.2007.06.024
  16. Figueiredo GB, Snyder ME. Long-term follow-up of a custom-made prosthetic iris device in patients with congenital aniridia. J Cataract Refract Surg. 2020;46(6):879-887. doi:10.1097/j.jcrs.0000000000000175
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  18. Toygar O, Snyder ME, Riemann CD. Pars plana vitrectomy through a custom flexible iris prosthesis. Retina. 2016;36(8):1474-1479. doi:10.1097/IAE.0000000000000959

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