MR Imaging Features of Giant Reservoir Formation in the Orbit: An Unusual Complication of Ahmed Glaucoma Valve Implantation

T.Y Jeon,C Kee,S.T Kim,T.-Y Chung,H.-J Kim

doi:10.3174/ajnr.a0610

Abstract

We report the MR imaging findings of an unusually large fluid collection, so-called giant reservoir, around an Ahmed glaucoma valve implant that caused progressive proptosis in a patient with posttraumatic glaucoma. Although other cystic lesions of the juxtalacrimal area of the orbit, such as dermoid cyst, can present similar imaging findings, the characteristic morphology and location should lead the radiologist to the correct nature of this cystic lesion.

Highlights

Glaucoma drainage devices provide an alternative treatment in complicated and refractory glaucoma cases.[1,2] The Ahmed glaucoma valve (AGV) implant (New World Medical, Rancho Cucamonga, Calif) is 1 of the common ocular tube devices currently used for this surgical technique
Glaucoma drainage implants are being increasingly used in recent years and have been used successfully for the treatment of complicated glaucomas, including neovascular glaucoma, aphakic and pseudoaphakic glaucoma, postpenetrating keratoplasty glaucoma, pediatric glaucoma, and uveitic glaucoma.[6,7]
The AGV implant, first introduced in 1993, consists of a drainage tube made of silicone and a scarab-shaped endplate made of either polypropylene or silicone (Fig 2)

Summary

Introduction

Glaucoma drainage devices provide an alternative treatment in complicated and refractory glaucoma cases.[1,2] The Ahmed glaucoma valve (AGV) implant (New World Medical, Rancho Cucamonga, Calif) is 1 of the common ocular tube devices currently used for this surgical technique. It has a unidirectional valve designed to offer a set resistance to the aqueous outflow from the anterior chamber with an intraocular pressure of 8 mm Hg or less.[3,4] The aqueous humor forms a fibrous encapsulated bleb on the endplate of the implant, which is resorbed through intercellular spaces and the lymphatic system of the adjacent periocular tissues. We present the MR imaging features of the giant reservoir formed after AGV implantation that caused progressive proptosis in a patient with posttraumatic glaucoma

Discussion

Conclusion