Effect of Steepest-Meridian Clear Corneal Incision in Reducing Preexisting Corneal Astigmatism Using Meridian-Marking Method or Surgeon’s Intuition
Narrative Responses:
Purpose
To compare the effect of steepest-meridian clear corneal incision (SM-CCI) for reducing preexisting corneal astigmatism between eyes that underwent SM-CCI using a meridian-marking method and those that underwent SM-CCI using surgeon's intuition.
Methods
One hundred eyes of 50 patients scheduled for phacoemulsification surgery were randomized to one of two groups: A) a 2.65-mm SM-CCI using the meridian-marking method, or B) a 2.65-mm SM-CCI using the surgeon's intuition. Regular and irregular corneal astigmatism, surgically induced astigmatism vector (SIA), refractive status, higher-order aberrations (HOAs), uncorrected (UDVA) and corrected distance visual acuity (CDVA), and physical meridian misalignment of SM-CCI measured using an anterior segment-optical coherence tomography were evaluated preoperatively and at 1 and 3 months postoperatively.
Results
The mean meridian misalignment of SM-CCI was significantly smaller in the meridian-marking group (4.4 ± 2.8°) than in the surgeon's intuition group (8.6 ± 4.4°; P < .0001). The regular and irregular corneal astigmatism, and corneal HOAs did not change significantly after surgery in either group. No significant difference was found between the meridian-marking group and surgeon's intuition group in the regular and irregular corneal astigmatism, refractive cylinder, manifest spherical equivalent value, SIA, HOAs, and UDVA or CDVA throughout the follow-up period.
Conclusion
The physical meridian misalignment of SM-CCI was significantly smaller when based on the meridian-marking method than when based on the surgeon's intuition, but the effect of the difference was not large enough to decrease remaining astigmatism and HOAs, or to improve UDVA.