Implantation techniques for reconstruction of anterior segment after ocular trauma

2021-12-24 10:13:49 By : Mr. Mension Machinery

Traumatic iris defects may cause severe ocular discomfort after blunt or penetrating injury to the eye. In complex cases, they can be associated with other pathologies such as corneal scars, traumatic cataract, glaucoma, and posterior segment complications. Often these eyes have to undergo more than one surgery until final rehabilitation is achieved. In cases with insufficient iris tissue for primary repair, an iris prosthetic device can be implanted to reduce photophobia and improve visual acuity.

The device used in this series is the Artificial Iris Customflex (henceforth referred to as AI, Human Optics, Erlangen, Germany). The implant is not for cosmetic eye color change but a prosthesis for functional ocular rehabilitation. It is a purely posterior chamber device and not to be implanted in phakic eyes. In this article, Krishnan VM, Todorova MG, Wiechens B, Valmaggia C, Varde MA introduced some implantation techniques of this device in various challenging cases.

This retrospective interventional study was done for 6 eyes that received an artificial iris as secondary reconstructive measure for photophobia and unsatisfactory vision following initial globe repair. Different implantation techniques were employed. These included simple sulcus implantation, implantation of a composite (iris prosthesis with attached intraocular lens) implant, and combinations with phacoemulsification, vitrectomy, and penetrating keratoplasty.

In all cases, the artificial iris was implanted successfully. In the follow‑up period (1–48 months), postoperative complications included rhegmatogenous retinal detachment, prolonged intraocular inflammation, and corneal transplant decompensation due to graft rejection. There was no case of secondary glaucoma. Complications could be managed successfully. All patients showed improved best‑corrected visual acuity and were satisfied with functional and cosmetic results.

There are two foldable colored, silicone‑based iris implants available:

Bright ocular iris implants® were developed for cosmetic change of iris color in normal eyes. The implantation was therefore in phakic eyes into the anterior chamber, which resulted in disastrous complications such as secondary glaucoma and uveitis. However, there have been some case reports detailing posterior chamber implantation in pseudophakic and aphakic eyes for reconstructive purposes with good results. In this study, authors used the AI in cases with partial and complete aniridia as well as in pseudo‑ and aphakia. All patients benefitted from the procedure. Four patients showed improvement in BCVA as well as in reduction of glare. In two patients, the visual acuity did not improve because of ocular comorbidity. Some case series have demonstrated visual improvement after iris reconstruction, whereas others could not demonstrate improvement in visual acuity.

This case series highlights different implantation techniques for a custom‑made silicone iris prosthesis and offers some insight into its possible uses in anterior segment reconstruction following severe trauma to the globe. The indication for an iris prosthesis, independent of the device chosen, has to take the patient's symptoms, activities, age, and comorbidities of the eye into account. Authors have discussed several possible complications associated with a foldable silicone iris prosthesis in traumatic aniridia. These are largely caused by an additional foreign body in the eye, the surgery needed for implantation, the localization of the implant, and comorbidities due to the initial trauma.

The AI implant is a versatile iris prosthesis that can be utilized in partial or complete aniridia. The implant is used in pseudophakic or aphakic eyes strictly for placement in the posterior chamber for functional indications and not for cosmetic change of iris color.

In this case series, Authors demonstrate some implantation techniques (simple sulcus implantation, suture fixated, composite graft with posterior chamber IOL, open‑sky implantation and combination with a toric sclera‑fixated IOL) in six eyes with traumatic aniridia. All patients benefitted from the surgery, most of them with improved visual acuity, and reduction in photophobia. Authors also had to consider significant comorbidities in these traumatized eyes and a higher incidence of complications. There is definitely a learning curve, but we feel that the major plus points of the Customflex remain the versatility, implantation via a small incision and superior cosmesis. It is therefore a valuable contribution to the armamentarium of anterior segment reconstruction and should be considered in traumatic aniridia. Due to the small number of cases presented, study cannot draw any conclusions regarding the safety profile or efficacy of the implant.

Source: Krishnan VM, Todorova MG, Wiechens B, Valmaggia C, Varde MA. The artificial iris –Analysis of various implantation techniques after ocular trauma. Indian J Ophthalmol 2021;69:3526-31.

Dr Ishan Kataria has done his MBBS from Medical College Bijapur and MS in Ophthalmology from Dr Vasant Rao Pawar Medical College, Nasik. Post completing MD, he pursuid Anterior Segment Fellowship from Sankara Eye Hospital and worked as a competent phaco and anterior segment consultant surgeon in a trust hospital in Bathinda for 2 years.He is currently pursuing Fellowship in Vitreo-Retina at Dr Sohan Singh Eye hospital Amritsar and is actively involved in various research activities under the guidance of the faculty.