Guidance
4 Efficacy
4 Efficacy
This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
4.1 A case series of 150 patients (158 eyes) who had type I corneal graft–keratoprosthesis implantation reported that preoperatively only 9% of eyes had best corrected visual acuity (BCVA) of 20/200 or better. Postoperatively, 70% (97/138) of eyes had BCVA of 20/200 or better at a median follow‑up of 6.3 months; 30% (41/138) of eyes did not have BCVA of 20/200 or better because of pre‑existing posterior segment conditions. The probability of maintaining the same vision at 7 years (n=97 eyes; estimated with Kaplan–Meier survival curves) was 50%.
4.2 The case series of 150 patients (158 eyes) reported an overall device retention rate of 84% at 2 years and 67% (89/133) at 7‑year follow‑up.
4.3 The case series of 150 patients (158 eyes) reported device removal in 33% (44/133) of patients at 7‑year follow‑up. In 25% (35/139) of eyes, the device was removed (30/139) or the eye was enucleated (5/139) as a result of device‑related complications during follow‑up.
4.4 The case series of 150 patients (158 eyes) reported that 12% (5/42) of eyes had repeated keratoprosthesis implantation because of recurrent corneal melts with device extrusion.
4.5 A case series of 24 patients who had corneal graft–keratoprosthesis implantation (type I in 23 patients) reported significant improvement in postoperative vision‑related quality of life (assessed using the National Eye Institute Visual Functioning Questionnaire [NEI VFQ‑25]) at 3‑month follow‑up when compared with baseline scores (patient‑reported visual function overall score: 43.1 at baseline versus 70.0 at 3 months [p<0.001]). Subscale scores within the NEI VFQ‑25 showed significant improvement in general vision, near and distance activities, social functioning, mental health, role difficulties, dependency, colour vision and peripheral vision (p<0.05). The improvement was also seen when comparing baseline scores with postoperative scores at an average follow‑up of 16 months.
4.6 The specialist advisers listed key efficacy outcomes as improvement in visual acuity, adequate management of glaucoma and device retention.