Purpose
To revisit the clinical paradigm of sterile vitritis in Boston keratoprosthesis (Kpro) recipients with delayed, culture-negative, vitreous inflammation.
Methods
A retrospective chart review was performed of 346 adult patients with a Boston Kpro, performed by three surgeons at the Massachusetts Eye and Ear Infirmary between January, 2000 and August, 2013. Patient demographics, treatments, and outcomes were recorded and analyzed.
Results
38/346 Boston KPro recipients developed vitreous inflammation between 2 days and 8.5 yrs after surgery. 23/38 patients had no obvious cause for vitreous cells. 20/23 had Type I KPros. 6/23 had prior auto-immune disease. 10/23 had repeat episodes (32 total events, median 3, range 2-7). Mean time between repeat episodes was 8.66 months (range 2 wks-7.2 yrs) Prior to each episode, all patients were on a fluoroquinolone, 16/23 on prednisolone acetate, and 9/23 on vancomycin. On presentation, 17/23 received retrotenons injection of triamcinolone acetate (20-40 mg). 7/23 patients presented with signs and symptoms suggestive of infectious endophthalmitis. 11/23 had a vitreous tap for culture; all of these vitreous samples were negative except for 1 patient with S. epidermidis. Vision decline was variable (median loss of 6.5 lines on Snellen chart, range 0-24). Median time to best recovered vision was 13.5 weeks, but 5/23 never recovered baseline vision. 17/23 developed late complications, including retroprosthetic membrane (13), glaucoma (8), cystoid macular edema (3), and retinal detachment (2).
Conclusions
Many cases of vitreous inflammation after Boston KPro implantation have no identifiable trigger, and are termed “sterile vitritis”. The paradigm for sterile vitritis after KPro includes sudden, painless loss of vision with full recovery of vision upon treatment with periocular steroids. However, this model may not apply in all cases. Not all patients with sterile vitritis after KPro recover baseline vision. Patients with a Boston KPro can present with vitritis that mimics infectious endophthalmitis, yet be culture negative. Full recovery of baseline visual acuity is not guaranteed. Roughly 45% of sterile vitritis cases recur, despite chronic topical corticosteroids. Repeat idiopathic vitreous inflammation may be particularly difficult to treat. Idiopathic vitritis may represent just one of several manifestations of chronic inflammation after Boston KPro.
Keywords: 575 keratoprostheses •
763 vitreous •
557 inflammation