clinical outcomes of stage 2 (pivotal) use of a modified keratoprosthesis device (orc-kpro) in patients with end-stage corneal blindness

Purpose: to investigate the short-term results and performance of a modified boston keratoprosthesis device manufactured by the ophthalmic research center (orc-kpro) in patients with end-stage corneal blindness.methods: this prospective interventional case series was conducted on patients with corneal blindness who were candidates for kpro. the inclusion criterion comprised patients with a best-corrected visual acuity (bcva) of less than 20/200 in both eyes, in whom the main reason for vision loss was corneal pathology. the orc-kpro was implanted using the method previously described for boston kpro.results: this study focused on 12 eyes of 12 patients with an average age of 45.9 ± 16.8 (range, 19 to 70) years. eleven patients were male. the kpro indication was corneal blindness due to chemical burns in nine patients (75%) and failure of multiple previous corneal grafts in three patients (25%). anatomical success was achieved in all patients. the preoperative bcva was light perception (lp) in 10 eyes and hand motion in 1 eye. except for one patient who was diagnosed with grade c proliferative vitreoretinopathy during the surgery, the vision of all other patients (91.6%) improved after surgery. the retroprosthetic membrane (rpm) was formed in two eyes (18.1%) after six months. of the 12 patients, 10 (83.3%) were under treatment with two antiglaucoma medications before surgery. the intraocular pressure of three eyes (25%) was estimated to be high by tactile palpation; however, it decreased in two eyes to the acceptable range. one patient underwent retinal surgery due to total retinal detachment, and two patients (16.7%) underwent vitrectomy due to endophthalmitis.conclusion: the current study showed that, in the short term, the use of orc-kpro achieved favorable anatomical success in patients with corneal blindness. however, the functional success rate was limited by the low visual potential due to advanced glaucoma in most patients.