Management of Anterior Chamber Dislocation of Dexamethasone Implant

Abstract

Purpose: To report dislocation of dexamethasone implant (Ozurdex®) into the anterior chamber and to discuss intervention options.

Design: Interventional case report.

Methods: An 89-year-old woman presented after Ozurdex® implant injection for chronic cystoid macular edema secondary to idiopathic intermediate uveitis. The dexamethasone implant dislocated into the anterior chamber. Pharmacologic dilation was administered and the patient was placed in a reclined supine position.

Results: Successful repositioning of the implant into the vitreous cavity.

Conclusions: Although it is a rare complication, anterior dislocation of a dexamethasone implant may have serious consequences. Early recognition and appropriate management is advisable.

KEYWORDS::

• Anterior chamber dislocation
• Cystoid macular edema
• Dexamethasone intravitreal implant
• Intermediate uveitis
• Ozurdex^®

Ozurdex®, a 0.7-mg dexamethasone intravitreal implant used for the treatment of macular edema, has recently received FDA approval for use in noninfectious posterior uveitis.The dexamethasone implant may control intraocular inflammation for up to 6 months and, unlike the previously approved fluoracetonide implant, is injected in the office using a 22-gauge delivery system.

The most commonly reported complication of the dexamethasone implant is a mild to moderate elevation in intraocular pressure, maximal at around 3 months, which has been reported in previous studies as an elevation of at least 10 mmHg in 12–33% of treated eyes. No statistically significant difference has been observed in cataract formation unless the patient has been treated with repeated dexamethasone implants.^1,2 The possible anterior dislocation of the implant is rare, and therefore its management is less frequently discussed in the literature.^3–6

CASE REPORT

An 89-year-old pseudophakic white female with a history of a chronic cystoid macular edema secondary to idiopathic intermediate uveitis in her left eye was treated with an in-office injection of Ozurdex®, after previous repetitive treatment attempts with intravitreal triamcinolone acetonide (4 mg/0.1 mL) and with bevacizumab (1.25 mg /0.1 mL) failed to resolve the edema. She presented 2 months after Ozurdex® injection with complaints of sudden onset of blurred vision in her left eye. She noticed a “white strip” in her left eye, but denied any pain or discomfort.Her best-corrected Snellen visual acuity deteriorated to 20/80, from her baseline of 20/40. Intraocular pressure was measured at 22 mmHg in the left eye, as compared with 12 mmHg in her right eye.Theanterior segment exam revealed that the dexamethasone implant had migrated into the anterior chamber posterior to her anterior chamber intraocular lens and was directly obstructing her central visual axis, as shown in Figure 1. Her pupil was pharmacologically dilated with tropicamide and phenylephrine in the office and she was positioned in a reclining chair with her face upward for a period of half an hour, resulting in the successful migration of the implant back to the vitreous cavity and decrease in her intraocular pressure to 12 mmHg within the same time period.

FIGURE 1  Anterior segment photo of the 89 year-old female demonstrating dexamethasone implant migration into the anterior chamber behind the anterior chamber intraocular lens.

The location of the dexamethasone implant posterior to the anterior chamber intraocular lens in our patient was fortuitous as it allowed for this noninvasive intervention. Had the implant migrated anterior to the anterior chamber intraocular lens, a different approach may have been necessary. The few previously reported cases of dexamethasone implant dislocation into the anterior chamber have occurred in either pseudophakic or aphakic patients.^3–6 These reports have demonstrated corneal edema, elevated intraocular pressure, or repeated dislocation and relocation of the implant between the vitreous cavity and the anterior chamber. Surgical explantation of a dislocated implant is sometimes necessary^3,5,6 to manage either corneal decompensation or elevated intraocular pressure.Minimizing the need for surgical intervention may be achieved by repositioning of the implant with a 30-gauge needle under topical anesthesia at the slit lamp,⁴ or with the patient posturing to reposition the dexamethasone implant back into the vitreous cavity.³ However, the use of these techniques must be tailored to the individual case, depending on both the location and positioning of the dexamethasone implant relative to other intraocular structures and how friable the implant has become with time.

While dislocation of a dexamethasone implant may have serious consequences requiring surgical explantation, in cases such as ours where the implant is dislocated for only a very short period of time, it is possible for it to be positioned back into the posterior chamber by patient posturing. Corneal toxicity can be minimized and invasive techniques may be avoided.Similar maneuvers have been used in repositioning a dislocated crystalline lens in Marfan syndrome.⁷ Posturing and the use of miotics may help prevent dislocation from recurring.Thus, when a patient is aphakic or does not have an intact posterior capsule, additional caution should be used when using the Ozurdex® implant. Although ophthalmologists may feel more comfortable using Ozurdex® in pseudophakic patients because of eliminated concern for possible cataract formation or progression, pseudophakia may also confer an increased relative risk of implant dislocation.Although this complication is quite rare, it is important to discuss its possibility with patients, especially those who are pseudophakic, as early detection can translate into noninvasive intervention, minimal or no corneal decompensation, and continued use of the implant to control intraocular inflammation.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.