This retrospective study evaluated the visual, refractive, tomographic and topometric outcomes of progressive-thickness intracorneal ring segment (PT-ICRS) implantation in patients diagnosed with duck-type (oval) keratoconus.
Following the creation of a corneal tunnel with a femtosecond laser, a single PT-ICRS was placed in the inferior half of the cornea, where the ectasia was most pronounced. Uncorrected and corrected distance visual acuity, refraction values, keratometry measurements, corneal asphericity (Q value) and topometric indices indicating corneal irregularity were compared before and after surgery.
In the study, which evaluated 31 eyes with a mean follow-up of approximately 9 months, a significant increase in visual acuity and a marked reduction in spherical and cylindrical refractive errors were found. Corneal steepening, astigmatism and the Q value decreased significantly, and improvement was observed in the great majority of the topometric indices that indicate corneal irregularity. No procedure-related vision loss or serious complication was observed.
In conclusion, PT-ICRS implantation is an effective and safe treatment option in duck-type keratoconus, providing significant improvement in visual and structural parameters by reducing the steepness and asymmetry of the cone.
Prof. Dr. Efekan Coşkunseven