Fluocinolone Acetonide Implant Removal From the Vitreous Cavity

Abstract

Purpose: To describe a technique for fluocinolone acetonide implant removal from the vitreous cavity. Methods: A case report and review of surgical methods were performed. Results: The technique to remove a fluocinolone acetonide implant from the vitreous cavity was safe and effective. The vitreous cutter was used to align the implant coaxially with a 25-gauge cannula. The valve of the cannula was opened, creating pressure that drew the implant into the cannula. Conclusions: Fluocinolone acetonide implants can be efficiently removed from the vitreous cavity by creating a pressure differential using the valved cannula. Advantages of this technique include avoiding invasive maneuvers such as enlarging the sclerotomy or creating a corneal wound.

Introduction

Fluocinolone acetonide is available as an intravitreal corticosteroid implant used in the management of diabetic macular edema (DME). It consists of a nonbiodegradable polyimide tube (3.50 mm length, 0.37 mm diameter) and an internal matrix that contains the steroid. ¹ The 0.12 μg/day fluocinolone acetonide implant (Iluvien, Alimera Sciences) with sustained release for 36 months was approved by the National Institute for Health and Care Excellence in 2013. ²

Adverse effects of the intravitreal steroid implant include ocular hypertension and cataract. Complications of the intravitreal injection include vitreous hemorrhage, retinal tear, retinal detachment, and endophthalmitis. Implant migration into the anterior chamber can also be an issue. A case report ³ discussed fluocinolone acetonide implant dislodgement into the infusion cannula during vitrectomy that was caused by fluctuations during the procedure. The implant was flushed out after the case. Indications for implant removal could include uncontrolled intraocular pressure (IOP), endophthalmitis, iatrogenic subretinal injection, and implant migration.

At present, there are no guidelines on fluocinolone acetonide implant removal from the vitreous cavity. A study by Knight et al ⁴ described bimanual approaches with a forceps and a vitreous cutter to remove the fluocinolone acetonide implant in porcine eyes. In one technique, the fluocinolone acetonide implant was stabilized with a forceps and a 25-gauge or 23-gauge vitreous cutter was used to eliminate it on low-cute rate settings using a bimanual technique. However, this technique is not efficient and leads to longer operating times. It also requires placing another sclerotomy for chandelier placement to perform this technique successfully. In another technique, the implant is grasped with a 27-gauge forceps and removed through the 25-gauge or 23-gauge cannula. ⁴ However, a 27-gauge forceps may not always be available.

We describe a new noninvasive technique in which a pressure differential is created by opening the valve of the 25-gauge (or 23-gauge) cannula, drawing the implant into the cannula.

Case Report

A 73-year-old woman with a history of proliferative diabetic retinopathy status after panretinal photocoagulation, DME status after intravitreal bevacizumab injections, and a dexamethasone implant in both eyes was referred for evaluation of a nonclearing vitreous hemorrhage and a lamellar hole in the right eye. She reported decreased vision several months previously.

The best-corrected visual acuity was 20/400 OD and 20/50 (pinhole 20/40) OS. She was pseudophakic, and a dilated fundus examination of the right eye was significant for vitreous hemorrhage and asteroid hyalosis, limiting the view to the macula (Figure 1), and a dexamethasone implant pellet (Ozurdex, Allergan, Inc) inferiorly. Optical coherence tomography of the right eye showed intraretinal fluid, an epiretinal membrane (ERM), and a lamellar hole vs a full-thickness macular hole (MH); however, the view was limited by the vitreous hemorrhage. Intravitreal bevacizumab was given in the right eye and on follow-up with her local retina provider, the patient had insertion of a fluocinolone acetonide implant in the right eye. Given the nonclearing vitreous hemorrhage, the patient was interested in surgery.

Figure 1.

Widefield fundus photograph of the right eye shows a vitreous hemorrhage, asteroid hyalosis obscuring the macula, and degraded dexamethasone implant inferiorly.

A 25-gauge pars plana vitrectomy was performed. After the vitreous hemorrhage and asteroid hyalosis were cleared, a chronic-appearing full-thickness MH was seen with traction from an ERM. Tissue blue was used to stain, and the internal limiting membrane (ILM), ERM, and hyaloid were peeled using an ILM forceps. A temporal ILM flap was created. A more complete peripheral vitrectomy was performed with removal of the degraded dexamethasone implant. The fluocinolone acetonide implant was noted to fall back to the posterior pole. The decision was made to remove the implant to prevent future complications of implant migration in this post-vitrectomized eye with an MH.

The fluocinolone acetonide implant was aspirated into the vitreous cutter mouth so that it was perpendicular to the vitreous cutter. It was then aligned coaxially with the other 25-gauge cannula. A 0.12 forceps was used to open the valve of the cannula. The IOP was transiently increased to 60 mm Hg, and aspiration was released. The implant was drawn into the cannula. The cannula was removed with a 0.12 forceps, and a light pipe was used to expel the intact implant out of the cannula (Figure 2 and Supplemental Material). A fluid–air exchange was performed, and 14% perfluoropropane was placed. The sclerotomies were closed with 6-0 plain gut, and subconjunctival antibiotics were given.

Figure 2.

(A) Using the vitrector, the fluocinolone acetonide implant is aligned coaxially with the 25-gauge cannula. The 0.12 forceps is used to stent open the valve of the cannula. (B) The intraocular pressure is raised. Aspiration on the vitrector is released. The implant is drawn into the 25-gauge cannula. (C) The trocar cannula is removed with a 0.12 forceps, and the light pipe is used to expel the implant from the cannula. (D) The implant is intact after removal from the cannula.

Conclusions

We describe a noninvasive technique for fluocinolone acetonide implant removal from the vitreous cavity. This technique uses the pressure gradient that is created when the cannula valve is open, which draws the implant into the cannula.

At present, there are no guidelines on how to remove a fluocinolone acetonide implant from the vitreous cavity. However, rare circumstances, such as uncontrolled IOP or endophthalmitis, may necessitate implant removal. In our case, the decision was made to remove the fluocinolone acetonide implant to prevent complications from implant migration in the future. This patient was found to have an MH and was vitrectomized, and the implant was lying on the posterior pole after the peripheral shave. If the fluocinolone acetonide implant remained in place, there was a potential for it to tamponade against the macula with local toxicity.

Our technique is noninvasive and efficient in removing a fluocinolone acetonide implant from the vitreous cavity. Proper orientation and alignment are crucial. A vitreous cutter or a forceps can be used to grasp the implant. In the case reported here, we were already using the vitreous cutter for the core vitrectomy and peripheral shave and continued using it for implant removal instead of opening a new instrument. First, the implant should be perpendicular to the vitreous cutter mouth as it is aspirated. Next, it should be aligned coaxially with and brought adjacent to the cannula. Increasing the IOP in the eye and opening the valve of the cannula with the 0.12 forceps creates a pressure difference that propels the implant into the cannula. In this case, vitrectomy was performed using the Constellation system (Alcon, Inc) with intraocular compensation on. The patient’s eye level was adjusted at the priming step.

This technique does not require creating corneal wounds or enlarging sclerotomies to remove the implant. Once the implant is in the cannula, the cannula can be removed with a 0.12 forceps and a light pipe or another instrument can be used to expel the implant from the cannula. The implant has a diameter of 0.37 mm and can fit through a 25-gauge cannula (0.45 mm diameter) and 23-gauge cannula (0.65 mm diameter). In addition, the implant’s length is 3.5 mm, and the entirety of the implant can fit in the standard cannula, which has a length of 4.0 mm.

This technique can be applied to remove the 0.18 mg fluocinolone acetonide intravitreal implant (Yutio, EyePoint), which is used for noninfectious posterior uveitis. This nonbiodegradable intravitreal implant is the same length (3.5 mm) and diameter (0.37 mm) as the Iluvien implant. ⁵ This technique can be challenging when removing the biodegradable 0.7 mg dexamethasone (Ozurdex) implant, which is used for macular edema from retinal vein occlusions, DME, and noninfectious posterior uveitis. For this implant, the dexamethasone is contained in a Novadur system, which contains a polymer matrix that degrades over time. Depending on the integrity of the implant and timing from placement of the implant, it tends to shred when grasped with a forceps or may be aspirated completely into the vitrector mouth, making it difficult to apply this technique. If the implant was recently placed and has not significantly eroded, this technique may still be used. The Ozurdex implant has a diameter of 0.46 mm and length of 6.0 mm. Therefore, with an intact (not yet degraded) implant, a 23-gauge cannula (0.65 mm diameter) should be used because it may not fit through the 25-gauge cannula (0.45 mm). In our case, the patient had a degrading Ozurdex implant, which was cut away and with the vitrector.

In conclusion, we describe a noninvasive and efficient technique to remove fluocinolone acetonide implants from the vitreous cavity. With proper alignment and pressure differences, the implant is removed intact without the need to create another wound or enlarge a sclerotomy.