Comparison Of Rrefractive Outcomes And Safety Of Refractive Surgery With Treated Optical Zone Of 6.5 Vs. 7.0

To evaluate the postoperative visual quality outcomes, efficacy and safety of photorefractive keratectomy (PRK) or femtosecond LASIK surgery with 6.5-mm and 7.0-mm optic zones.

Care-Laser center, Tel-Aviv, Israel

This retrospective cohort study included a total of 298 eyes who underwent femtosecond LASIK or PRK surgery for myopia or myopia with astigmatism. A comparison of Group A (148 eyes of 148 patients) who underwent surgery using optic zone 7-mm diameter, with a matched group B (148 eyes of 148 patients), using optic zone 6.5-mm was conducted. Two months postoperatively, uncorrected distance visual acuity (UCVA),best corrected visual acuity, efficacy index, safety index, ablation depths and Pupil Decentration were assessed.  

Both groups did not differ significantly in their demographics. Preoperatively, no significant difference was found in best corrected and uncorrected distance visual acuity (P=0.25 and p = 0.69 , respectively). Postoperatively, both groups had a mean UCVA of 0.0 LogMAR. Group A had higher efficacy index and safety index (p=0.044 and p=0.46, respectively), with deeper ablation depth (P<0.001). Both PRK and LASIK has similar outcomes.

Both LASIK and PRK treatments with 7-mm and 6.5-mm optical zones are very successful and safe in correcting myopia and astigmatism. While all had excellent efficacy and safety indexes, a larger optical zone (7-mm) was found superior to 6.5-mm in both parameters.