Alfonso Bartolozzi, BelénLisa Fernández, CarlosFernández-Vega Cueto, LuisMadrid Costa, DavidAlfonso Sánchez, José F.2023-06-162023-06-162021-11-042296-858X10.3389/fmed.2021.771365https://hdl.handle.net/20.500.14352/4578Received: 06 September 2021; Accepted: 04 October 2021;Published: 04 November 2021Purpose: To assess the outcomes of implanting a new polymethylmethacrylate (PMMA) ring (Neoring; AJL Ophthalmic) in pre-descemet deep anterior lamellar keratoplasty (PD-DALK) procedure for moderate-advanced keratoconus. Methods: This prospective study included 10 eyes of 10 patients with moderate-advanced keratoconus who underwent PD-DALK with Neoring implantation. Neoring was implanted in a pre-descemetic pocket. The post-operative examination included refraction, corrected distance visual acuity (CDVA), corneal tomography, and endothelial cell density (ECD). The root mean squares (RMSs) for coma-like aberrations and spherical aberration were evaluated for a pupil size of 4.5mm. The junctional graft (Tg) and host (Th) thicknesses were measured. The post-operative follow-up was 24 months. Results: Post-operative CDVA was 0.82 ± 0.14 (decimal scale), 100% of the eyes achieved a CDVA of 0.7 (decimal scale). The refractive cylinder was −2.86 ± 1.65 2-years after surgery. No eyes had a post-operative refractive cylinder ≥5.00 D and in five eyes (50%), it was ≤2.50 D. At the last visit, the mean keratometry was 45.64 ± 1.96 D, the RMS for coma-like aberrations was 0.30 ± 0.15μm and spherical aberration was 0.22 ± 0.09. The mean ECD remains without changes over the follow-up (P = 0.07). At the last visit, Tg and Th were 679.9 ± 39.0 and 634.8 ± 41.2μm, respectively. The thickness of the complex (host-Neoring) was 740.6 ± 35.6μm. In all cases, this thickness was thicker than Tg. Conclusion: The results of this study suggest that PD-DALK along Neoring implantation is a viable, effective, and safe option to optimize the post-operative results for moderate-severe keratoconusengAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttps://doi.org/10.3389/fmed.2021.771365open access617.713-007.64-089615.46:617.713681.735Corneal transplantDeep anterior lamellar keratoplasty (DALK)Visual outcomesRefractive outcomesKeratoconusCirugíaOftalmologíaMateriales ópticos3213 Cirugía3201.09 Oftalmología2209.14 Propiedad ópticas de los sólidos