HARVARD DEPARTMENT OF OPHTHALMOLOGY
Category : Clinical Research Candidate : Chhavi Saini Poster #: C13
Restoration of Vision in Severe , Cicatricial , Ocular Surface Disease with the Boston Keratoprosthesis Type II
Chhavi Saini , Teresa C . Chen , Lucy H . Young , Demetrios G . Vavvas , Mark Vangel , George N . Papaliodis , Shizuo Mukai , Angela V . Turalba , Douglas J . Rhee , David M . Wu , Dean Eliott , John B . Miller , Brian J . Song , Lucy Q . Shen , Louis R . Pasquale , James Chodosh
Purpose : The Boston Keratoprosthesis type II ( BK2 ) device may be the only viable option to salvage vision in patients with severe cicatrizing ocular surface disease . The prior BK2 model was modified to the present day ( click-on ) model in 2009 . We assessed clinical outcomes of the current click-on BK2 model .
Methods : Study Design and Study Participants : This was a retrospective cohort study including all BK2 surgeries at Massachusetts Eye and Ear ( MEE ) from June 2009 to March 2021 . One eye per participant was included . For patients with both eyes eligible , the eye with maximum follow-up was considered for univariate and time-to-event analysesDevice Design and Assembly : The BK2 click-on model consists of a front plate made of clear polymethyl methacrylate plastic and a back plate made of titanium . The front plate is placed face down on the adhesive patch followed by the donor cornea , and then the slitted “ click-on ” titanium back plate . The back plate is secured in place with gentle pressure by the assembly tool
Results : 56 eyes of 53 patients with a mean follow-up of 45.8 months were included . Visual Outcome : Visual acuity improved from LogMAR 2.2 ± 0.5 preoperatively to 1.5 ± 1.2 at final follow-up . 89.3 % saw ≥20 / 200 at some point postoperatively . Of the eyes with a follow-up of more than 5 years , 50.0 % retained a visual acuity of ≥20 / 200 at their final follow-up . Complications : The most common complications were de-novo or worsening glaucoma ( 41.1 %), choroidal effusions ( 30.3 %), retinal detachment ( 25.0 %) and end-stage glaucoma ( 25.0 %). Preoperative systemic immunosuppressive therapy was associated with retention of ≥20 / 200 acuity .
Conclusions : At 5 years postoperatively , approximately 50 % of eyes with the BK2 retained a BCVA better than preoperative BCVA . For patients with severe cicatricial corneal blindness , implantation of a BK2 offers the potential for long term visual function but can also be associated with vision threatening complications .