Subjective Refractive Surgery Outcomes Are Comparable Between 3 Procedures

The safety, efficacy, and predictability of SMILE, LASIK, and ICL have been widely shown in the literature, but subjective outcomes are less clear.

Subjective refractive surgery outcomes of 3 types of procedures are mostly comparable, with glare, visual fluctuations, and halos reported as the most frequent postoperative visual symptoms, according to findings published in BMC Ophthalmology. The researchers reviewed patient experiences 3 months following either femtosecond assisted laser in situ keratomileusis (FS-LASIK), lens replacement (LR), and laser assisted lenticule extraction (LALEX).

The researchers analyzed 131 eyes of 131 patients (mean age, 26.5±4.6 years; mean preoperative spherical equivalent -4.95±2.04 diopters [D]) with myopia. Patients underwent FS-LASIK (n=73), LALEX (specifically, small incision lenticule extraction [SMILE, using the VisuMax femtosecond laser, Carl Zeiss Meditec]; n=35), or lens replacement (specifically, implantable collamer lens [ICL; STAAR Surgical]; n=23).

The study authors determined subjective refractive surgery outcomes by having participants complete the Quality of Vision (QOV) questionnaire 3 months after surgery. The researchers analyzed the survey results, baseline characteristics, treatment parameters.

Between different techniques, the safety and efficacy indexes were comparable. The safety indexes were 1.21±0.18, 1.22±0.18, and 1.22±0.16, and the efficacy indexes were 1.18±0.20, 1.15±0.17, 1.17±0.15 for LALEX, FS-LASIK and LR, respectively. Mean overall QOV scores were 13.40±9.11, with mean frequency, severity, and bothersome score of 5.40±3.29, 4.53±3.04, and 3.48±3.18 for LALEX, FS-LASIK and LR, respectively. No significant differences in overall subjective refractive surgery outcomes were noted between different techniques.

For the 10 visual symptoms evaluated, only halos were found to be significantly different among different procedures.

Overall, glare was the symptom with the highest scores, followed by fluctuation in vision and halos. The only significantly difference in subjective refractive surgery outcome between techniques were halos (P <.000).

“For the 10 visual symptoms evaluated, only halos were found to be significantly different among different procedures,” the research team reports. While the LR procedure investigated had significantly more halos, the study clarifies that these halos were not more bothersome than those associated with FS-LASIK or LALEX procedures.

Mesopic pupil size was identified, using ordinal regression analysis, as a risk factor (P =.037), while postoperative uncorrected distance visual acuity (UDVA) was a predictive factor for overall QOV scores (P =.037). Patients with larger mesopic pupil size were identified using binary logistic regression analysis as being at increased risk for experiencing glare postoperatively.

Patients with better postoperative UDVA were less likely to report blurred vision and focusing difficulty. Patients experienced focusing difficulties and difficulty judging distance or depth perception more frequently due to having larger residual myopic sphere postoperatively.

The researchers explained that previous studies had not explored characterizing subjective refractive surgery outcomes using the QOV 3 months postoperative, and that patients of all 3 procedures reported visual symptoms.

Study limitations include its lack of analyzing objective QoV, and its lack of including pre-operative QoV scores.


Du H, Zhang B, Wang Z, Xiong L. Quality of vision after myopic refractive surgeries: SMILE, FS-LASIK, and ICL. BMC Ophthalmol, 23(1):291. Published online Jun 26, 2023. doi:10.1186/s12886-023-03045-6