Wavefront-Guided Treatment of Irregular Corneas Using High-Resolution Aberrometer
Narrative Responses:
Purpose
To evaluate the visual, refractive, contrast sensitivity, topographic and aberrometric outcomes in highly aberrated corneas treated by wavefront-guided LVC surgery using the iDesign high definition aberrometer and the Star S4IR excimer laser platform from Abbott Medical Optics.
Methods
A retrospective case series study of 20 eyes of 16 patients with highly aberrated corneas that were treated by wavefront-guided ablation using iDesign aberromter between November 2012 and June 2013. Corneal irregularity was due to 3 main clinical causes: I- Keratoconus post CXL (11 eyes), II- Post RK (3 eyes), III- Post LASIK decentration/Irregular ablation (6 eyes). Eyes were treated by PRK/MMC (group I & II) or LASIK enhancement (group III). Pre and postoperative refraction, UCDVA, BCDVA, Contracst sensitivity, Corneal tomography, Corneal irregularity indices and aberrometry maps were studied. All eyes were followed up for more than 6 months.
Results
Mean patiens’ age was 33±9 years. Mean preoperative objective sphere, cylinder and spherical equivalent of the total sample were -0.78±1.97 D, -2.65±1.54 D and -2.10±1.80 D, while postoperative values were -0.33±0.70 D, -1.1±0.73D and 0.88±0.88 D respectively. LogMAR of the preoperative BCDVA was 0.62±0.27 while the postoperative UCDVA was 0.20±0.10. There was a postoperative gain in BCDVA of one line in 10% and 2 lines or more in 90% of eyes. Mean preoperative Total RMS and HOA RMS (µm) were 2.37±0.73 and 1.47±0.62 while postoperative were 1.08±0.55 and 1.02±0.36 respectively. Contrast sensitivity and corneal irregularity indices showed significant postoperative improvement.
Conclusion
The New iDesign Symstem can measure highly aberrated eyes and provide a reliable ablation profile; allowing safe and effective refractive correction. This can improve both visual performance and corneal irregularity in such challenging cases in which old low resoultion aberrometers were not able to measure them.