Visual impairment from corneal stromal disease affects millions worldwide. We describe a cell-free engineered corneal tissue, bioengineered porcine construct, double crosslinked (BPCDX) and a minimally invasive surgical method for its implantation. In a pilot feasibility study in India and Iran (clinicaltrials.gov no. NCT04653922), we implanted BPCDX in 20 advanced keratoconus subjects to reshape the native corneal stroma without removing existing tissue or using sutures. During 24 months of follow-up, no adverse event was observed. We document improvements in corneal thickness (mean increase of 209 ± 18 µm in India, 285 ± 99 µm in Iran), maximum keratometry (mean decrease of 13.9 ± 7.9 D in India and 11.2 ± 8.9 D in Iran) and visual acuity (to a mean contact-lens-corrected acuity of 20/26 in India and spectacle-corrected acuity of 20/58 in Iran). Fourteen of 14 initially blind subjects had a final mean best-corrected vision (spectacle or contact lens) of 20/36 and restored tolerance to contact lens wear. This work demonstrates restoration of vision using an approach that is potentially equally effective, safer, simpler and more broadly available than donor cornea transplantation.

角膜基质病导致的视力障碍影响着全世界数百万人。我们描述了一种无细胞工程角膜组织、生物工程猪结构、双交联 (BPCDX) 及其植入的微创手术方法。在印度和伊朗的一项试点可行性研究中（clinicaltrials.gov no. NCT04653922），我们在 20 名晚期圆锥角膜受试者中植入 BPCDX，以重塑天然角膜基质，而无需去除现有组织或使用缝合线。在24个月的随访期间，没有观察到不良事件。我们记录了角膜厚度的改善（印度平均增加 209 ± 18 µm，伊朗平均增加 285 ± 99 µm）、最大角膜曲率（印度平均减少 13.9 ± 7.9 D，伊朗平均减少 11.2 ± 8.9 D）和视力（至印度的平均隐形眼镜矫正视力为 20/26，伊朗的眼镜矫正视力为 20/58）。 14 名最初失明的受试者中有 14 名最终平均最佳矫正视力（眼镜或隐形眼镜）为 20/36，并且恢复了对隐形眼镜佩戴的耐受性。这项工作证明了使用一种与供体角膜移植同样有效、更安全、更简单且更广泛可用的方法来恢复视力。