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Changes in coma aberration after rings implantation for keratoconus Felipe Sánchez Trancón, Agustín Peñaranda, Fernando Ojeda Tecnolaser Sanchez Trancon, Espanha

Background and objectives: In keratoconus there’s a detachment of the corneal apex to the lower hemisphere, increasing the coma aberration according to the degree of keratoconus. We have evaluated the evolution of coma aberration (Z 3, + / -1) to determine the degree of detachment caused by implantation of an intrastromal corneal ring. Material and methods: We used intracorneal rings of Ferrara (Keraring) of different thickness and length of arc. The technique used to put the ring was femtosecond laser. The counting was carried out with endothelial specular microscope. Keratoconus was assessed before and after surgery with the corneal topographer Pentacam, adapting the area of study to the central 6mm. Results: topographic comparison of 50 cases of keratoconus. Coma evaluation, symmetry and corneal topography. Determination of VA and refraction. Conclusions: The implantation of intrastromal rings produces applanation of the area of corneal protrusion induced by the keratoconus. The value of coma aberration Z3, 1 is a coefficient that indicates the degree of applanation achieved the regularity of corneal symmetry and improvement of visual acuity. The axis of coma aberration indicates the position on which we must place the segments.




CIOCV'09 Proceedings  

Proceedings for the International Conference of Optometry and Visual Science 2009 (CIOCV'09). University of Minho, Braga, Portugal