Mucosal complications in osteo-odonto keratoprosthesis (OOKP) surgery

Abstract

Abstract Purpose To study the mucosal complications of osteo-odonto-keratoprosthesis (OOKP) surgery from the UK national keratoprosthesis cohort. Methods A retrospective study was conducted at the Sussex Eye Hospital, Brighton, UK. The case records of patients who underwent OOKP surgery were reviewed and analysed. Results The cohort contained 64 patients, among which 25 were females and 39 were males. Eyelid and adnexal abnormalities were treated in 69% of the cases prior to OOKP surgery. Mucosal graft complications after OOKP affected 46% of the cases after stage 1 and 22% after stage 2. Most of the complications were observed in cases with autoimmune conditions like Stevens-Johnson syndrome (43% post-stage 1, 59% post-stage 2) and cicatrising conjunctivitis (31% post-stage 1, 20% post-stage 2). On the contrary, mucosal overgrowth covering the anterior surface of the optic, which was noted in 28% of the cases, was a common complication after stage 2. Thinning and ulceration of the mucosa was noted in 22% of cases after stage 2. Laminar exposure due to mucosal ulcers was identified in 11 cases. The central part of the mucosa was frequently affected by thinning and ulceration after stage 1. The mucosa overlying the supero-nasal corner of the lamina was eroded commonly after stage 2 leading to exposure of the lamina. Mucosal thinning after stage 1 was treated with conservative measures such as observation and increased lubrication in 15 cases, and with surgical procedures in 7 cases. Post-stage 1 mucosal ulcers were mostly treated by surgery (7 out of 8 cases). Following stage 2, minor cases of mucosal ulcers and thinning and three cases of overgrowth were conservatively treated with lubrication and observation. However, 18 cases of overgrowth required surgical excision. All cases of lamina exposing ulcers were surgically treated. Surgical treatment of mucosal defects included mucosal grafts, flaps and eyelid corrections. Fusion of the eyelids and conversion to a trans-palpebral OOKP were performed in two cases to treat resistant mucosal ulcers. Two eyes lost lamina as a consequence of lamina exposing ulcers. One lamina was explanted due to severe resorption and one due to infection. Conclusion The majority of surgical revisions following OOKP surgery are due to mucosal problems, such as mucosal thinning and ulcerations. These may be treated with increased lubrication of the mucosa or surgical closure of the defects. Mucosal defects resulting in laminar exposure can be a serious threat to laminal viability, and must be treated promptly and aggressively.