Corneal Lenticule Extraction For Advanced Refractive Correction (Clear) In Patients With High Myopia.

to assess CLEAR safety and efficacy in patients with more than -5 dioptres (D) of myopia.

Centre for Research in Refractive Surgery (Poggibonsi, Italy).
Siena Eye Laser Refractive and Cataract Surgery Clinic (Poggibonsi, Italy).

retrospective study of CLEAR procedures performed at Siena Eye Laser (Poggibonsi, Italy) with Ziemer FEMTO LDV femtosecond laser. Inclusion criteria were corrected distance visual acuity (CDVA) ≥ than 0.2 logMAR, age ≥18 years or older, myopia > -5D, and suitable for CLEAR. Patients were evaluated at baseline, post-operative day 1 (POD1) ,6 and 18 months.

we included 250 eyes of 183 patients.At baseline, mean spherical equivalent refractive error (SER) was -8.5±1.6 D,with a mean cylinder of -1.0±0.8 D.CDVA was 0.0 logMAR in all eyes.Mean corneal thickness was 508.9±25.0 microns.Expected residual stroma thickness (RST) calculated by Ziemer platform was 245.1±15.1 microns.At POD1 uncorrected distance visual acuity (UDVA) was 0.11±0.1logMAR,and mean SER was -0.4±0.6 D.RST was 266.3±29.3μ and significantly higher than the predicted value (p<0.001).At 6 months,mean UDVA was 0.0±0.1 logMAR (p<0.001),RST was 262±15.2 microns (p>0.05) and mean SER was -0.2±0.3D (p>0.05) as compared to POD1.At 18 months,residual SER was +0.1±0.5D and mean UCDVA was 0.0±0.1 logMAR compared to 6 months FU (all p>0.05).

In patients with high myopia, CLEAR showed good predictability and efficacy, with excellent correction of the refractive defect and stability at 18 months follow-up. Interestingly, post-operative residual stromal thickness was significantly higher than the predicted value by the laser software.