Hairline cracks in osteo‐odonto‐keratoprosthesis: An Achilles' heel

• Published in: Acta ophthalmologica (Oxford, England) Vol. 100; no. S275
• Main Authors: Liu, George, Naveed, Hasan, Liu, Christopher
• Format: Journal Article
• Language: English
• Published: Malden Wiley Subscription Services, Inc 01.12.2022
• Subjects: Acuity; Antibiotics; Autografts; Biopsy; Blindness; Bone grafts; Computed tomography; Cornea; Corneal transplantation; Endophthalmitis; Literature reviews; Polymethylmethacrylate; Root resorption; Streptococcus infections
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2022.0421

Purpose: Background: The osteo‐odonto‐keratoprosthesis (OOKP) is the device of choice for restoring sight in end‐stage corneal blindness not amenable to conventional corneal transplantation. A bio‐integrable lamina created from an autologous single‐rooted tooth is used to frame a PMMA optical cylinder. The lamina is sealed by an overlying buccal mucous membrane graft. An OOKP has a survival rate of 80% over 18 years. The lamina is subject to resorption over time. Clinical and radiological observation are essential for detecting impending laminar failure. Aims: Case report and literature review to illustrate the limits of clinical and radiological observation of an OOKP. Methods: Retrospective case study of a 40‐year‐old male with bilateral corneal blindness from Stevens Johnson Syndrome, first presenting in 1996 with light perception vision, underwent left Stage 1 (March 1997) and Stage 2 OOKP (June 1997) surgery. Post‐operatively, his visual acuity was 6/5+ (1.2, 20/15). Results: Regular CT imaging revealed no loss of volume or impending failure. He presented with severe eye pain on 11.12.2016, having had a normal quarterly review 5 days beforehand. He underwent endoscopic vitrectomy, biopsy and intravitreal antibiotics on 12.12.2016 for endophthalmitis (Group B Streptococcus). Despite efforts to treat his infection, his left eye was eviscerated on 16.12.2016. Later study of the lamina revealed a hairline crack not visible on CT imaging. Conclusions: We discuss an unforeseen case of a failed OOKP lamina due to a hairline crack despite limited laminar resorption. Current management options for failing laminae include insertion of a new lamina, bone morphogenetic protein ± bone graft, an alternative device, and removal of device and closure of the corneal opening with a small full thickness corneal graft. Hairline cracks remain an Achilles' heel. There should be a high index of suspicion of endophthalmitis even in the presence of good laminar bulk.