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Updated: Jul 12, 2026
05:46
Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
Corneal Asphericity Preservation via Spatially Selective Peripheral Stromal Volume Ablation Following
Bo Zhao1, Bo Yuan1,2, Yutong Liu2
1Tianjin Aier Eye Hospital, Tianjin University, Tianjin, China.
Journal of Refractive Surgery (Thorofare, N.J. : 1995)
|July 10, 2026
Summary
Ray-tracing-guided LASIK (RT-LASIK) offers better visual outcomes and reduced spherical aberration compared to Q-value-guided LASIK (Q-LASIK). RT-LASIK achieves this by preserving corneal asphericity through greater stromal volume ablation in the 3-5mm zone.
Area of Science:
- Ophthalmology
- Refractive Surgery
- Corneal Imaging
Background:
- Laser in situ keratomileusis (LASIK) is a common refractive surgery.
- Optimizing visual quality and corneal morphology post-LASIK remains an area of research.
- Different guidance systems, such as ray-tracing and Q-value, may influence outcomes.
Purpose of the Study:
- To compare postoperative visual quality between ray-tracing-guided LASIK (RT-LASIK) and Q-value-guided LASIK (Q-LASIK).
- To analyze spatial corneal morphological changes in central and pericentral optical zones after these procedures.
Main Methods:
- A comparative study involving 60 eyes (30 RT-LASIK, 30 Q-LASIK) with similar preoperative myopia.
- Corneal zones (0-3mm, 3-5mm, 5-7mm) were analyzed.
- Corneal ablation ratio (CAR) in terms of thickness (tCAR) and stromal volume (vCAR) was calculated.
Main Results:
- RT-LASIK showed superior uncorrected distance visual acuity, spherical equivalent, and 3-mm Strehl ratio at 3 months.
- Higher vCAR was observed in the 3-5mm zone for RT-LASIK; tCAR did not differ.
- RT-LASIK resulted in attenuated Q-value change and greater spherical aberration reduction across optical zones.
Conclusions:
- RT-LASIK provides superior visual performance postoperatively.
- This advantage is linked to preserving corneal asphericity and reducing spherical aberration.
- Greater stromal volume ablation in the paracentral 3-5mm annulus mediates the optical benefits of RT-LASIK.
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