Work

Intermediate Term Results of a Novel Minimally Invasive Keratoprosthesis

Year: 2026

Type: article

Abstract: Purpose: Keratoprosthesis implantation remains a sight-restoring option in high-risk corneal transplantationwhere conventional keratoplasty is unlikely to succeed.Existing devices, such as the Boston Keratoprosthesis (B-KPro), are very effective but long-term results are limited by glaucoma, infections, retroprosthetic membrane (RPM) formation, and retinal complications.We developed a minimally invasive keratoprosthesis (mi-KPro) that couples an ultrathin nitinol backplate with a poly(methyl methacrylate) optic and is implanted with a modified deep anterior lamellar keratoplasty (DALK) technique. Design: Experimental study in rabbits.Subjects: Thirty New Zealand White rabbits.Methods: Rabbits received severe alkali or acid corneal burns and 1-month later treated with mi-KPro or penetrating keratoplasty (PKP); an additional cohort underwent B-KPro implantation in naïve eyes.Animals were followed for up to 12 months with serial slit-lamp photography, intraocular pressure (IOP) measurements by intracameral manometry and TonoPen, and anterior and posterior segment optical coherence tomography.Main Outcome Measures: Endpoints included device anatomic retention, RPM formation, infection, angle status, retinal thickness, and optic nerve axon density on histology.Results: The modified DALK approach allowed reproducible mi-KPro implantation with the nitinol backplate seated over Descemet's membrane and the optic extending into the anterior chamber through a 2.5-mm trephination.mi-KPro eyes maintained clear optics without RPM, haze, or neovascularization and showed stable IOP at last follow-up (15.5 ± 2.2 vs 15.6 ± 1.5 mmHg at baseline; p = 0.138).In contrast, all PKP grafts failed within 2.2 ± 0.7 months with marked corneal edema, neovascularization, and sustained IOP elevation despite timolol.B-KPro eyes developed early, refractory IOP rise and staphyloma.Tonopen readings strongly correlated with intracameral IOP (r = 0.95, p = 0.001).OCT and histology demonstrated preservation of angle anatomy, retinal thickness, and optic nerve axons in mi-KPro eyes, whereas PKP eyes exhibited significant retinal thinning (p = 0.004) and axon loss (p = 0.01).Conclusions: mi-KPro combines a minimally invasive surgical approach with a flexible nitinol backplate to achieve long-term retention, stable IOP, and preservation of posterior segment structure in severe chemical injury.These data support mi-KPro as a promising next-generation keratoprosthesis for high-risk corneal blindness. J o u r n a l P r e -p r o o fMinimally invasive keratoprosthesis (Mi-KPro) preserved intraocular pressure, retinal and optic nerve structure, and achieved superior retention with low infection and retroprosthetic membrane rates compared with penetrating keratoplasty and Boston Keratoprosthesis in rabbit chemical injury models. J o u r n a l P r e -p r o o f

Source: Ophthalmology Science

DOI: 10.1016/j.xops.2026.101117