Boston Keratoprosthesis Type 1 Implantation With Resultant No Light Perception Vision
The Boston Keratoprosthesis (KPro) type 1 leads to significant visual improvement in eyes with very poor visual prognosis. However, significant complications can arise after implantation. Our objective was to evaluate and better understand poor outcomes, specifically no light perception (NLP) vision after KPro.
This retrospective chart review was conducted on 10 patients (12 eyes in total), including 3 women and 7 men, who underwent KPro type 1 implantation with resultant NLP vision at last follow-up. Variables studied include pre-operative diagnosis, preoperative best-corrected visual acuity (BCVA), BCVA after KPro implantation, timing of NLP vision, cause of NLP vision and KPro complications. Descriptive statistics were used.
The mean age was 46.0±22.9 years. Pre-operative diagnoses were aniridia (5), HSV ulcer (2), corneal decompensation secondary to congenital glaucoma (1), failed graft due to lattice dystrophy (2), and congenital hereditary endothelial dystrophy (1) and Stevens-Johnson syndrome (1) Pre-operative BCVA was ≤ 20/200 in all 12 eyes. Post-operative BCVA improved in 9 patients, was stable in 1 patient and worsened in 1 patient on average 4.45±5.47 months after surgery. NLP vision occurred 2.09±1.74 years after implantation. The causes of NLP vision were terminal glaucoma (5), persistent retinal detachment (4), and corneal melt with KPro extrusion (1).
NLP vision was an unfortunate outcome post-KPro implantation. The KPro did provide better vision for 2 years before failing in these eyes with a previously poor visual function.