Vitrectomy for ciliary block (malignant) glaucoma

Abstract

Background: Ciliary block (malignant) glaucoma is a rare surgical complication occurring in patients with pre-existing glaucoma. Misdirected aqueous fluid causes forward movement of the lens/iris diaphragm, shallowing the central and peripheral anterior chamber. Although most patients with ciliary block respond to medical or laser therapy, those with refractory glaucoma often require pars plana vitrectomy to normalize aqueous flow.

Methods: The medical records of 21 consecutive patients with refractory ciliary block glaucoma treated by pars plana vitrectomy were reviewed retrospectively to determine the efficacy of this procedure in alleviating ciliary block. Data were collected regarding anatomic characteristics of the eye, history of glaucoma, prior ocular surgery, and outcome after vitrectomy.

Results: Pre-existing glaucoma and recent intraocular surgery were noted in all patients with ciliary block glaucoma. Of 21 eyes, 8 (38%) had undergone multiple prior intraocular surgeries. The initial pars plana vitrectomy was successful in alleviating ciliary block in 14 (70%) of 20 eyes. Of those six eyes that failed to improve after initial vitrectomy, five (83%) were phakic. Additional vitrectomy surgery to relieve ciliary block was required in three (60%) of five phakic patients who failed initial vitrectomy. Complications during the treatment of ciliary block included cataract formation, retinal detachment, bleb failure, and serous choroidal detachment.

Conclusions: Pars plana vitrectomy is a useful adjunct to therapy for ciliary block glaucoma when medical and laser treatment fail to alleviate the process. Surgically removing the anterior hyaloid to re-establish normal aqueous flow constitutes the primary goal of surgery. In some cases, surgery is compromised by poor visualization of the anterior hyaloid, avoiding glaucoma filtration sites, and guarding against damage to the crystalline lens.