Visual Rehabilitation in end stage Inflammatory Ocular Surface Disease with the Osteo-Odonto-Keratoprosthesis (OOKP): Results from the United Kingdom

Abstract

Aims: To report the long term results of osteo-odonto-keratoprosthesis (OOKP) surgery in the visual rehabilitation of patients with corneal blindness from end stage inflammatory ocular surface disease.

Methods: A non-comparative retrospective case series of 36 consecutive patients treated at the National OOKP referral centre in Brighton, United Kingdom, between November 1996 and March 2006.

Results: A total of 36 patients, with age ranging from 19 to 87 years (mean 51 ± 19 years), were included in the analysis. The main preoperative diagnoses were Stevens Johnson syndrome (n=16, or 44%), severe thermal or chemical burns (n=6, or 17%), and mucous membrane pemphigoid (n=5, or 14%). The remainder of the cases comprised miscellaneous causes of dry eye (n=9, or 25%), which included one each of graft versus host disease, ectodermal dysplasia, ionising radiation damage, cicatrising conjunctivitis from topical medication, trachoma, congenital trigeminal nerve hypoplasia, linear IgA disease, Sjogren's syndrome, and nutritional deficiency. Follow-up ranged from 6 months to nine years (mean 3.86 ± 2.45 years). Anatomical retention during the entirety of the follow-up period was seen in 72% of patients. The main factor resulting in anatomical failure was resorption of the OOKP lamina, which occurred in seven cases (or 19%). Predicted resorption in three cases resulted in successful planned exchange of the lamina, but two cases underwent emergency removal of the OOKP, and two cases developed endophthalmitis. HLA matched allografts suffered a higher rate of laminar resorption. Out of the entire cohort, thirty patients (or 83%) had some improvement in vision, twenty eight (or 78%) achieved vision of 6/60 or better, and nineteen (or 53%) achieved 6/12 or better. The best-achieved vision was retained throughout the follow-up period in 61% of cases. Survival analysis suggested that the probability of retaining vision >6/60 five years after surgery was 53%±10%. Vision threatening complications occurred in 9 cases (or 25%), and included endophthalmitis, retinal detachment, and glaucoma. De novo glaucoma occurred in six patients (or 24%) but was seen overall in seventeen patients (or 47%), ten of whom required surgical treatment.

Conclusion: OOKP surgery can restore useful and lasting vision in patients suffering from end stage ocular surface disease, for whom conventional corneal surgery is not possible. The main problems seen in this study were laminar resorption, particularly in allografts, and glaucoma.