Aggressive Epithelial Downgrowth Following Non-Valved Glaucoma Drainage Device Implantation And Sutureless Intrascleral Haptic Fixation: A Case Report And Literature Review

To report a rare and complex case of aggressive epithelial downgrowth (EDG) manifesting in an eye with previous extensive history of both anterior and posterior segment surgical interventions. The case highlights the cumulative risks from multiple surgical conduits in facilitating epithelial incursion even in an era of small incision ocular surgeries where such incidences are rare. A comprehensive literature review was also performed to investigate the incidence of similar recent cases and evaluate modern treatment strategies, such as the role of targeted antimetabolites.

This patient was managed in the Ophthalmology department of a tertiary hospital. The patient was co-managed by a multi-disciplinary team of ophthalmologists including a glaucomatologist, vitreoretinal surgeon and a cornea specialist.

A 51-year-old male with a history of right eye primary open-angle glaucoma and left eye ocular hypertension presented with a dislocated intraocular lens (IOL)-capsular complex in the right eye. Past ocular history was significant for a right eye pars plana vitrectomy with sulcus IOL and implantation of a non-valved glaucoma drainage device (Baerveldt) complicated by bleb encapsulation. The patient underwent elective right eye IOL removal and sutureless intrascleral haptic fixation (Yamane technique) with an uneventful recovery. Four months postoperatively, he presented with a two-weeks history of blurred vision and photophobia. Examination showed pupillary distortion and low-grade anterior chamber inflammation. A translucent retrocorneal membrane with a scalloped advancing edge was noted, extending from the glaucoma tube entry site onto the corneal endothelium and iris, associated with rise in intraocular pressure (IOP). The diagnosis was EDG. Based on multidisciplinary consultation with the cornea and glaucoma teams, the patient was started on topical steroids and given an intracameral injection of 5-fluorouracil to arrest the cellular proliferation. Despite that, the membrane continued to increase in size, along with aggressive rise in IOP and mild subluxation of the SFIOL. He is currently still under active management with plans for bleb injection of mitomycin-C 0.02% for IOP control and possible membranectomy should the epithelial membrane affect the central cornea.

Epithelial downgrowth was previously seen more frequently in large incision cataract surgeries or penetrating keratoplasties but have now massively declined, with incidences shifted towards eyes with multiple surgical conduits. In multi-operated eyes, non-valved glaucoma shunts and sutureless haptic fixation sites may serve as cumulative entry points. There is currently no consensus with regards to treatment but options include surgical excision of the membrane and targeted pharmacotherapy. Intracameral 5-fluorouracil and methotrexate have demonstrated efficacy in arresting sheet-like proliferation. Early detection and prompt initiation of antimetabolites are critical for preserving endothelial health and managing secondary glaucoma.