Late-Onset Inadvertent Bleb Formation following Pars Plana M3 Molteno Implant Tube Obstruction

Purpose: To report a case of inadvertent bleb formation presenting 18 months after pars plana M3 Molteno implant tube obstruction in a patient with mixed mechanism glaucoma. Materials and Methods: An 84-year-old Caucasian male with mixed mechanism glaucoma underwent slit-lamp examination, gonioscopy, colour anterior segment photography and anterior segment optical coherence tomography (AS-OCT). Results: An inadvertent bleb developed 18 months after pars plana implant tube re-positioning with a 6/0 Vicryl tie ligature. The bleb was located in the area anterior to the implant plate; it was characterised by a thin, transparent, avascular and multi-cystic wall, with a visible stoma at the posterior edge of the bleb. The bleb was functioning as demonstrated by an intraocular pressure of 6 mm Hg at presentation and a punctate fluorescein uptake pattern of the bleb wall. The bleb over the plate of the Molteno implant was non-functioning, likely secondary to tube obstruction by vitreous in the early postoperative period. AS-OCT showed a tract from the anterior chamber commencing at an entry wound through a corneal tunnel to the posterior stoma at the base of the inadvertent bleb. Conclusions: We hypothesise that the pathophysiologic factors resulting in an inadvertent bleb are a result of a combination of apoptosis, late-onset wound dehiscence and internal gaping of a centrally placed corneal wound. In addition, aqueous hydrodynamic factors may play a role.

Postoperative opacification of polymethylmethacrylateintraocular lens

Background: Opacification of ophthalmic devices has been previously reported in silicone scleral buckle, Molteno implant, and intraocular lens opacification. However, there is no report on polymethyl methacrylate (PMMA) intraocular lens (IOL) calcification. Objective: Report the clinical feature, histopathologic and spectrophotometer analysis of opacified three-piece PMMA IOL. Method: A 60-year-old diabetic patient reported decreased visual acuity in her right eye, which had undergone phacoemulsification with PMMA IOL implantation. The ophthalmic examination revealed a white homogeneous opacification of posterior surface of the IOL. The explanted IOL was analyzed using scanning electron microscopy, energy dispersive spectroscopy, and alizarin red staining. Results: The scanning electron microscope analysis showed granular deposits on posterior surface of the IOL. Using energy dispersive spectroscopy analysis, calcium and phosphate peaks were revealed, which was confirmed by positive for alizarin red staining. Conclusion: This case report provided evidence of PMMA IOL calcification caused by calcium and phosphate deposits. The possible etiologies were extrinsic and/or intrinsic factors.