Malignant Glaucoma in a Pseudophakic Eye with Slack Lens Zonules

Abstract

Purpose: To report a case of malignant glaucoma after glaucoma surgery in a pseudophakic eye with slack lens zonules.Case summary: An 83-year-old man presented with high intraocular pressure of the left eye. He underwent cataract surgery in the left eye ten years ago. He was diagnosed with glaucoma two years ago and had used anti-glaucoma medications. The initial examination of the left eye revealed intraocular pressure of 24 mmHg and zonular dehiscence. We performed Ahmed valve implant surgery because medical treatment failed to lower the intraocular pressure. The anterior chamber angle was nearly closed. After the surgery, over-filtration of aqueous fluid was observed. Injecting the balanced salt solution into the anterior chamber demonstrated misdirected flow of aqueous fluid into the vitreous cavity behind the unstable intraocular lens. The eye was diagnosed with malignant glaucoma; therefore, pars plana vitrectomy was performed. After the vitrectomy, the anterior chamber was not deep; therefore, we repositioned the tip of Ahmed valve implant from the anterior chamber to the vitreous cavity. Subsequently, the anterior chamber became deep and intraocular pressure normalized. The patient remained stable two months after the vitrectomy.Conclusions: Malignant glaucoma can occur in pseudophakic eyes with slack lens zonules after glaucoma surgery, due to misdirection of aqueous fluid. This case suggests that the tip of Ahmed valve implant should be located in the vitreous cavity after vitrectomy, to prevent misdirected flow of aqueous fluid.