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Une migration atypique d’un implant de dexaméthasone : sandwich entre un implant cristallinien 3 pièces et une capsule postérieure intacte

Following intravitreal injection, various ectopic migrations of dexamethasone implants (DI) have been reported: just behind the crystalline lens and intraocular lens (IOL) in the anterior vitreous; or in the anterior chamber relatively stucked in the iridocorneal angle, especially when peripheral iridotomy or subluxated, sutured or iris-claw IOLs are present. Here we present the management of an uncommon location of DI : between sulcus 3-pieces IOL and intact posterior capsule.

This is a single atypical case of “a DI sandwich” in posterior chamber, in a previously phaco-vitrectomized eye with intact posterior capsule and stable sulcus IOL.

A 66-years old man had an everyday life injury traumatism while cutting wood with a wire brush cutter along a metallic fence: he consulted 3 days later for severe endophthalmitis and cataract with posterior iris synechiae, resulting in light perception on his left eye. A CT-scan excluded any metallic intraocular foreign body (FB). Initial emergency surgery consisted in phacovitrectomy without implantation, bacteriologic and fungal samples, removal of small wood FB, antibiotic & antifungal intravitreal injections. No zonulolysis was present, no capsular tear occurred. Two other series of intravitreal injections, local and systemic treatment allowed good anatomic recovery. No microbiological agent was found, only IL6 was very elevated (5000 pg/ml). At 1.5 month he developed Irvine-Gass syndrom (CME) despite adapted local therapy and acetazolamide per os. At 2 months, conditions allowed secondary implantation with a 3-pieces IOL in the sulcus: indeed, anterior and posterior capsules have totally fused with initial inflammation. During the same surgery, as zonule and lens bag were well preserved, we injected intravitreal DI without adverse event. Postoperatively, the DI was well located free in the posterior segment and the sulcus IOL was stable at different visits. Forty days after DI injection, he consulted in emergency because he thought he got a hay straw in his left eye. Actually, the DI migrated to the anterior segment, just between sulcus IOL and intact posterior capsule. He had no pain, no redness, normal IOP, 0.2 logMAR far & near vision, and just an impression of a paracentral scotoma. Precise medical questioning highlighted recent repeated heavy loads lifting with head down in his farm, despite postoperative instructions. Medical treatment based on myotics (isotpopilocarpine), continuation of anti-inflammatory drops, and prophylactic hypotonizing monotherapy drops, associated with monthly complete monitoring (slit lamp/OCT/specular microscopy) was decided. Spontaneous disintegration of this ectopic DI took 2 months and was well tolerated: CME disappeared completely in 1.5 month; IOL remained rather stable as it was a 3-pieces model, it was slightly tilted & displaced upward by the DI versus initial peroperative positioning; no IOP elevation or endothelial damage occurred; vision went to 0.0 logMAR and paracentral scotoma disappeared.

This singular ectopic location was never reported before. Various options could have been chosen: among YAG capsulotomy, emergency surgery, medical treatment especially with myotics & close monitoring; we preferred the last one, regarding terrain, symptoms, visual acuity and tolerance of the patient, avoiding potential additional traumatism.

This ectopic migration leading to DI sandwich enables all the same healing from a CME. Rigorous monitoring with precise iconographic sequences allows to estimate efficacy, safety and time of resorption in this position: it was more impressive than embarrassing.