Beyond Topography: Epithelial Remodeling After 320° Intracorneal Ring Implantation In Keratoconus — Manual Versus Femtosecond Laser Techniques

To evaluate corneal epithelial behavior after implantation of a single-segment 320° intracorneal ring in patients with keratoconus using sectoral epithelial mapping, comparing manual and femtosecond laser-assisted tunnel creation techniques.

Tertiary referral ophthalmology center.

Este estudo observacional retrospectivo incluiu 47 olhos de 47 pacientes com ceratocone submetidos a implante de um segmento de anel intracorneano de 320° entre maio de 2024 e maio de 2025. Os pacientes foram agrupados de acordo com a técnica de criação do túnel (manual ou assistida por laser de femtosegundo). O mapeamento da espessura epitelial foi realizado no pré-operatório e em 1 e 3 meses, com análise setorial de 17 regiões da córnea. As alterações foram expressas em relação ao valor basal (Δ1M e Δ3M). A análise estatística utilizou Equações de Estimação Generalizadas, incluindo tempo, técnica e interação tempo × técnica, com correção de Benjamini-Hochberg para comparações múltiplas.

Progressive epithelial thickening was observed after intracorneal ring implantation with both techniques, with greater magnitude at 3 months. Mean epithelial thickness increased in central, paracentral, and peripheral regions in both groups. In the femtosecond group, central thickening was significant at 3 months, whereas in the manual group it was significant at 1 month and more pronounced at 3 months. Sectoral analysis showed significant thickening in most sectors in both groups. However, no statistically significant difference was found between techniques in the temporal pattern of epithelial remodeling after correction for multiple comparisons.

Implantation of a 320° intracorneal ring segment in patients with keratoconus is associated with progressive and measurable epithelial remodeling within the first three postoperative months, involving central, paracentral, and peripheral corneal regions. The epithelial response pattern was similar between manual and femtosecond laser-assisted techniques, suggesting that epithelial remodeling is predominantly determined by the biomechanical effect of the implant, regardless of the tunnel creation technique. Epithelial mapping proved to be a sensitive and promising tool for evaluating corneal response after intracorneal ring implantation in keratoconus.