**Background:** Presbyopia, age-related accommodative deficiency, is a common condition that reduces near vision clarity. Corneal laser procedures like presbyLASIK offer reversible correction compared to intraocular lens replacement. Longitudinal spherical aberration (LSA) is a key high-order aberration that can be modulated to extend depth of focus. The Zhang & Zheng CLEAR-Q (ZZ-CLEAR-Q) strategy incorporates constraints on focus extension, LSA optical zone boundary, and anisometropia to personalize treatment. This study aimed to evaluate visual outcomes and satisfaction after ZZ-CLEAR-Q surgery.
**Methods:** This prospective observational study enrolled 116 consecutive patients (232 eyes) with presbyopia undergoing ZZ-CLEAR-Q at Hangzhou MSK Eye Hospital from December 2020 to January 2023. Inclusion criteria: age 40-52 years, myopia -0.50 to -6.00 DS, astigmatism 0.00 to -3.00 DC, corrected distance visual acuity 20/20 or better. Exclusion criteria included non-binocular correction, poor monovision tolerance, prior corneal surgery, corneal opacities, target optical zone <6.5 mm, inability to achieve target LSA, or contraindications to refractive surgery. Dominant eye was determined using hole-in-the-card test and lens fogging. Dominant eyes were treated for distance vision (target 0.00 D ocular LSA within 5.0 mm zone, refractive target -0.25 DS). Non-dominant eyes were treated for near vision (target -1.00 D ocular LSA within 5.0 mm zone, refractive target -1.00 DS). Target Q-factor was determined using the ZZ LSA formula (patent application 2019111386516). Outcomes assessed at 3 months included visual acuity (UCDVA, CDVA, UCNVA, DCNVA), distance-corrected defocus curve, patient satisfaction (VFQ25 questionnaire), corneal Q factor (Sirius tomography), ocular primary spherical aberration (PSA, Alcon analyzer), and manifest spherical equivalent (SE). Statistical analysis used paired t-tests, Wilcoxon signed-rank tests, and repeated-measures ANOVA.
**Key Results:** Mean age was 45.57±3.14 years (51 males). At 3 months, binocular UCDVA was 20/20 for 100% of patients. Binocular UCNVA was Jaeger 1 for 96% and Jaeger 2 for 100%. Patient satisfaction was 93.1% (108/116). Only 8 patients (6.9%) still required spectacles for near vision. No patients reported glare, halos, or significant dry eye. The monocular distance-corrected defocus curve showed dominant eyes had significantly better visual acuity at 0 D (P<0.001), while non-dominant eyes had significantly better visual acuity at all defocus levels except 0 D and -0.50 D (all P<0.05). At 3 months, anterior corneal Q factor values were -0.11±0.19 (dominant) vs -0.51±0.15 (non-dominant) (P<0.001). Ocular PSA values were -0.01±0.06 μm (dominant) vs -0.12±0.04 μm (non-dominant) (P<0.001). There were no significant differences between expected and achieved manifest SE, corneal Q factor, or ocular PSA for dominant eyes (P=0.159, 0.070, 0.094 respectively). For non-dominant eyes, no significant difference was found between expected and achieved SE (P=0.089) or corneal Q factor (P=0.475). No eye lost ≥2 lines of CDVA; one eye (3.3%) lost 1 line, and two eyes (6.67%) gained 1 line. No retreatments were needed.
**Clinical Implications:** ZZ-CLEAR-Q surgery effectively provides excellent distance and near vision with high patient satisfaction in presbyopic patients. The differential modulation of binocular LSA significantly improves near vision in non-dominant eyes without compromising distance vision in dominant eyes. The use of a personalized target Q-factor based on individual ocular LSA may improve refractive accuracy. The 5.0 mm optical zone was chosen to ensure full correction within the functional optical zone, avoiding peripheral aberration changes. Limitations include small sample size, single-surgeon bias, short follow-up (3 months), and lack of comparison with other presbyopia correction methods. Longer-term studies are needed to assess durability of effect as presbyopia progresses.