Keratometric index in keratoconic eyes before and after intracorneal ring segment implantation

• Autores: María Victoria de Rojas Silva, Antía Gestoso, Alejandra Gómez Arcia, Margarita de la Fuente Iglesias, María López, Renata Rodrígues, Isabel López, J. Pombo
• Localización: Journal of Emmetropia: Journal of Cataract, Refractive and Corneal Surgery, ISSN-e 2171-4703, Vol. 5, Nº. 1, 2014, págs. 9-13
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • OBJETIVE: To compare anterior and posterior corneal surface curvature in normal (control) eyes, keratoconic (KC) eyes and keratoconic eyes after intracorneal ring segment (KCICRS) implantation.

    SETTING: Complexo Hospitalario Universitario, A Coruña (Spain).

    METHOD: Retrospective study in which 30 eyes with KC before and after ICRS implantation and 30 control eyes were analyzed. The mean radius of the anterior (antR) and posterior (postR) corneal surface and true net power were determined using images from a rotating Scheimpflug camera, from which the antR/postR ratio and the mean keratometric index (KI) were calculated for each group.

    RESULTS: Mean antR and postR were 7.82 ± 0.31 mm and 6.42 ± 0.37 mm in control eyes, 6.94 ± 0.46 mm and 5.51 ± 0.5 mm in KC eyes, and 7.18 ± 0.5 mm and 5.5 ± 0.49 mm in KCICRS eyes, antR being significantly different between all groups (p = 0.0001) and postR significantly different between control and KC eyes and between control and KCICRS eyes (p = 0.0001). The antR/postR ratio between the three groups was significantly different (p = 0.0001). Mean KI between control, KC and KCICRS eyes was statistically different (p = 0.0001 KC vs. KCICRS, KCICRS vs. control; p = 0.012 KC vs.control).

    CONCLUSION: Anterior and posterior corneal curvature is significantly greater in KC eyes than in control eyes, with an increase in the antR/postR ratio. After ICRS implantation, the anterior surface is flattened, while there are no significant changes in the posterior surface.

    These findings suggest that the standard KI is not valid for calculating intraocular lens power in KC or KCICRS eyes.