| Purpose:To evaluate efficacy and preliminary safety of Moscow Eye Microsurgery Complex (MICOF) keratoprosthesis in eyes with complicated corneal opacities unsuitable for keratoplasty. To analyze the characteristics of glaucoma and sterile vitritis in patients underwent MICOF keratoprosthesis in China.Methods:Retrospective review of consecutive clinical case series. We analyzed 96 eyes of 96 patients who previously underwent MICOF keratoprosthesis implantation at our institution between Jan 1,2000 and Oct 31,2010. The longest follow-up after MICOF keratoprosthesis implantation (measured after the second stage of the implantation) was 10 years. MICOF Keratoprosthesis surgery involves two procedures. In Stage 1, a supporting titanium frame is inserted into the lamellar pocket; a polymethyl methacrylate (PMMA) optical cylinder is implanted 3-4 months later (Stage 2). Vitrectomy is usually done to remove the iris and lens in stage 2. Data was collected from the preoperative, intraoperative, and postoperative courses of the surgery. Statistical analysis was performed to identify factors influencing best corrected visual acuity (BCVA) and significant postoperative complications like glaucoma and sterile vitritis.Results:MICOF keratoprosthesis improved vision dramatically in most patients. The percentage of eyes with postoperative VA of 20/100 or better was 80.7%(67/83) at 6 months after Stage 2,82.4%(61/74) at 1 year,72.7%(40/55) at 2 years,78.8% (26/33) at 3 years,78.9%(15/19) at 4 years,100%(8/8) at 5 years,80%(4/5) at 6 years,100%(2/2) at 7 and 8 years, and 100%(1/1) at 9 years. The most common complication, retroprosthetic membrane formation (RPM), occurred in 39 eyes. Thirty-five of these required an additional surgical membranectomy to recover the BCVA. The overall keratoprosthesis retention rate was 100%, none was removed. However,16 eyes needed to be reinforced with the patient's own auricular cartilage. Retinal detachment (RD) occurred in one eye at two months after Stage 2. After pars plana vitrectomy, transscleral cryotherapy and inert gas filling surgery, the retina was reattached. Corneal melting and corneal infiltrate developed in 8 eyes respectively. Corneal cyst occurred in 5 eyes after MICOF keratoprosthesis implantation. Nine eys need cyclocryotherapy to control intraocular pressure (IOP) before MICOF keratoprosthesis implantation. Ten eyes presented with elevated IOP after implantation; three of these had underlying glaucoma. Five eyes received a cyclocryotherapy to control IOP after MICOF keratoprosthesis implantation. BCVA decreased from 20/25 to 20/100,20/80 to light perception,20/60 to 20/200,20/100 to hand movement, and 20/50 to counting fingers, respectively. Sterile vitritis occurred in 6 patients,1 to 30 months postoperatively. Two patients underwent pars plana vitrectomy as soon as the diagnosis was confirmed. Peribulbar injection of Dexamethasone, Tobramycin,1% Lidocaine (DG mixture) and antibiotics were used in the first 3 days of the other four patients. Triamcinolone (40mg) and intensive topical steroid therapy were applied then after. The recovery of vision was complete in 2 to 6 weeks.Conclusions:MICOF keratoprosthesis is an effective alternative for patients with corneal blindness and a poor prognosis for penetrating keratoplasty. Glaucoma is the most common comorbidity with keratoprosthesis. It presents a challenge after keratoprosthesis implantation. Sterile vitritis after MICOF keratoprosthesis would be an immune phenomenon similar to the nature of graft injection. The diagnosis and treatment strategies were of much importance to maintain the BCVA after MICOF keratoprosthesis implantation. |
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