Optimizing Plasma Formation and Minimizing Microcavitation to Enhance Clinical Outcomes in Keratorefractive Lenticule Extraction.

PURPOSE

To compare early postoperative visual outcomes and higher order aberrations (HOAs) between plasma and conventional keratorefractive lenticular extractions (P-KLEx and C-KLEx).

METHODS

In this retrospective case series, records of patients who underwent KLEx surgery using two protocols-C-KLEx (symmetric spot/track distance laser spacing, 100-nJ pulse energy, VisuMax 500; Carl Zeiss Meditec) or P-KLEx (asymmetric spot/track distance laser spacing, 85-nJ pulse energy, VisuMax 800; Carl Zeiss Meditec)-were reviewed. Both groups received an identical total energy dosage of 625 mJ/cm. Postoperative visual acuity and corneal higher order aberrations (HOAs) were analyzed at 1 day, 2 weeks, and 2 months.

RESULTS

Among 281 eyes, 136 and 145 were included in the C-KLEx and P-KLEx groups, respectively. At postoperative day 1, the mean uncorrected distance visual acuities (UDVAs) were 0.02 ± 0.04 and 0.01 ± 0.08 logarithm of the minimum angle of resolution (logMAR) in the C-KLEx and P-KLEx groups, respectively ( = .22); however, the P-KLEx group demonstrated significantly better mean UDVA at 2 weeks and 2 months postoperatively (both < .05). At 2 weeks postoperatively, the mean UDVAs were -0.01 ± 0.04 and -0.04 ± 0.07 logMAR in the C-KLEx and P-KLEx groups, respectively, and at 2 months postoperatively, the mean UDVAs were -0.02 ± 0.04 and -0.04 ± 0.06 logMAR, respectively. The P-KLEx group showed less induction of total HOAs, coma, and spherical aberration than the C-KLEx group (all < .05).

CONCLUSIONS

P-KLEx, which minimizes microcavitation and creates a lenticule with near-pure plasma, shows more favorable outcomes than C-KLEx, yielding better early postoperative visual acuities and reduced induction of corneal HOAs. .