Área Técnica: Córnea
Clinical Outcomes After Implantation of a New Intrastromal Corneal Ring with a 140-Degree of Arc Length in Patients With Corneal Ectasia
PURPOSE: To evaluate the clinical and tomographical outcomes of the implantation of new Ferrara intrastromal corneal ring segments (ICRS) with 140-degrees of arc in eyes with keratoconus.
: This study evaluated 67 eyes of 55 keratoconus patients that had Ferrara ICRS implantations from April 2010 to February 2015. Outcome measures included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction, keratometry (K), asphericity (Q) and spherical equivalent (SE). The measurement of visual acuity was made using a decimal scale. All patients were evaluated using the Pentacam Scheimpflug system (Oculus, Wetzlar, Germany).
The mean follow-up was 16.81 (±13.96) months. The UDVA improved from 0.22 preoperatively (±0.15) to 0.42 postoperatively (±0.25) and the CDVA improved from 0.38 (±0.20) to 0.59 (±0.21), the differences were statistically significant (p<0.001). The mean minimum keratometry (K1) did not change significantly as it reduced from 45.49 D (±6,38) to 45.14 D (±5,10) (P = 0.354). The mean K2 decreased from 54.11 D (±8,40) to 49.54 D (±5,11) (p<0.001). The average keratometry reduced from 49.8 D (±7,01) to 47.34 D (±4,90) (p<0.001). The average asphericity changed from -0.60 (±0,86) to -0.23 (±0,67) (p<0.001). The mean preoperative topographic astigmatism decreased from -8.0 D (±3,45) to -4.53 D (±2,52) (p<0.001).
A new ICRS with 140-degrees of arc was useful in treating corneal ectatic disorders as it can effectively improve the visual acuity and reduce the high astigmatism usually found in these patients.