Recurrent Glaucoma Drainage Device Erosion Associated with Occult Infection with Biofilm-producing Organisms

Aim: We report the first case of recurrent erosion of a glaucoma drainage device (GDD) associated with chronic infection with biofilm-producing bacterial organisms.

Presentation of Case: A 68-year-old Caucasian female was referred to a tertiary glaucoma service with uncontrolled left inflammatory glaucoma and cataract in association with Fuchs Heterochromic Iridocyclitis. Combined glaucoma drainage device (GDD) implantation and phacoemulsification cataract surgery was performed. Fourteen months post-operatively, the patient presented with recurrent GDD erosion requiring multiple ocular surface repairs over the next 12 months. The device was finally explanted and sent for microbiological analysis after all surgical strategies to control the refractory erosions were unsuccessful.

Discussion: Cultures of the GDD were positive for Streptococcus parasanguis and Rothia dentocarisoa;organisms commonly found in the oral flora. S. parasanguis is known to form biofilm and is a common cause of late prosthetic valve endocarditis. Both organisms were sensitive to chloramphenicol, and the patient responded to topical chloramphenicol therapy with good final vision and intraocular pressure control.

Conclusion: Mechanical factors are often used to explain GDD erosion. This case demonstrates that in recurrent GDD erosion, occult chronic infection, particularly with biofilm-producing organisms, should be considered in the differential diagnosis. Surgical repair of the erosion may have a low chance of success in occult or chronic infection and definitive GDD explantation may be required. With the current trend towards earlier and more frequent GDD implantation in glaucoma, it is likely that this problem will increase in prevalence.