Intravitreal Fluocinolone Acetonide (Retisert) Implantation Using a Keratome Blade

The fluocinolone acetonide intravitreal implant (Retisert; Bausch + Lomb, Rochester, NY) is a well-studied corticosteroid therapy used to control chronic noninfectious uveitis affecting the posterior segment of the eye. ¹ The implant is surgically placed in the vitreous of the eye for sustained and localized drug release. Surgical implantation of the device requires the creation of a 3.5- to 4-mm full-thickness sclerotomy at the pars plana. Conventional techniques use a 20-gauge microvitreoretinal (MVR) blade to create the sclerotomy wound. ² We demonstrate use of a 2.4-mm keratome blade to create the sclerotomy wound.

Our patient is a 34-year-old man with Vogt-Koyanagi-Harada syndrome. Owing to a complex and refractory clinical course, the decision was made to perform cataract extraction, intraocular lens placement, pars plana vitrectomy, and fluocinolone acetonide (Retisert) implantation. The right eye was treated first and is shown in our surgical video.

Technique

Port placement was performed prior to cataract phacoemulsification and intraocular lens placement. ³ Complex phacoemulsification required iris hooks and synechiolysis. A 60-degree limbal peritomy was performed in the eye to expose the inferonasal quadrant. Tenon’s capsule was dissected from its anterior insertion. External cautery was performed.

The implant was prepared by passing a double-armed 8-0 prolene suture through the strut hole. Two points were marked 3.5 mm posterior to the limbus and 4.0 mm apart. Using a 2.4-mm keratome, a scleral incision was made between the 2 marks (see Supplemental Video). Using a vitrector, any external vitreous at the wound was excised. The implant was then placed into the vitreous cavity with the drug tablet anteriorly using a needle holder to grasp only the strut and avoid the membrane overlying the drug tablet. To anchor the implant, each arm of the 8-0 prolene suture was placed through the inner scleral wound at half-depth and tied; the tails were left long and tucked under the interrupted 8-0 prolene sutures that were used to close the scleral wound. The sclerotomy wound was confirmed to be watertight at physiologic pressure. The conjunctiva was closed with 7-0 vicryl sutures. The implant was inspected on indirect ophthalmoscopy, and the position of the implant was noted to be appropriate with no overlying choroidal tissue, peripheral breaks, or choroidal detachments.

There were no immediate postoperative complications. Postoperative day 1 examination was remarkable for an intraocular pressure of 6 mm Hg, moderate dispersed vitreous hemorrhage, and a shallow nasal choroidal detachment outside of the equator. The implant was in place and no retinal detachment was noted. The remainder of the postoperative course was unremarkable; intraocular pressure returned to baseline by postoperative week 2 and the vitreous hemorrhage resolved by postoperative month 1.5. The patient’s vision improved from hand motion in the preoperative period to 20/30 at 6 months after surgery, with complete resolution of panuveitis.

Discussion

Use of a keratome to create the sclerotomy incision during intravitreal implantation of fluocinolone acetonide is a safe and effective technique. We have used this technique in 16 cases with good outcomes.

The theoretical advantage of this technique is smooth, uniplanar wound creation; an MVR blade involves sawing through sclera with multiple passes to reach at least 3.5-mm wound length and may thus create various planes. With the wider blade of the keratome, fewer passes are needed to extend the wound. With a perfectly linear wound, there was minimal damage to surrounding tissues, proper anatomical wound closure, and potentially shorter surgical time. Our technique is analogous to the use of a keratome rather than an MVR blade to create clear cornea incisions during cataract surgery.

A potential disadvantage of this technique is prolonged hypotony. Vitrectomy techniques such as oblique incision have been shown to reduce the incidence of postoperative hypotony because of improved wound closure from multiplanar scleral cuts. ⁴ A uniplanar incision for a sclerotomy wound could theoretically delay wound closure and increase hypotony. In a prospective study by Jaffe et al, ⁵ 12.5% of eyes that underwent fluocinolone acetonide intravitreal implantation using standard technique experienced postoperative hypotony (which resolved in 3-4 weeks) and 6% of patients had wound leaks. Among our 16 cases, only 1 (6.3%) operated eye was hypotonus postoperatively. No wound leak was detectable, and hypotony resolved after a few weeks without significantly affecting control of intraocular inflammation or final visual acuity. Further studies are needed to determine the success rate of this technique.