Changes in Vector Astigmatism After Superotemporal Versus Temporal Clear Corneal Incision Cataract Surgery

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Error Correction

Background:

• Cataract surgery aims to restore vision by removing the clouded lens.
• Clear corneal incisions (CCIs) are standard for cataract extraction.
• Incision placement may influence postoperative astigmatism, a key factor in visual outcomes.

Purpose of the Study:

• To compare the effects of superotemporal versus temporal CCIs on vector and refractive astigmatism after cataract surgery.
• To analyze changes in surgically induced astigmatism and residual astigmatism based on incision location.

Main Methods:

• A prospective study involving patients with age-related cataracts and mild corneal astigmatism (<1.5 D).
• Patients were randomized into superotemporal (R group) or temporal (L group) incision groups.
• Pre- and 6-month postoperative assessments included visual acuity, refraction, corneal topography, and anterior segment OCT to evaluate astigmatism, IOL position, and surgically induced astigmatism.

Main Results:

• Both incision types led to a significant reduction in non-corneal ocular residual astigmatism (N-CORA).
• Significant differences were observed between groups in the postoperative meridian of anterior corneal astigmatism and total corneal astigmatism.
• The superotemporal incision group showed a greater change in the J45 vector of surgically induced corneal astigmatism (SICA) for both anterior and total corneal surfaces compared to the temporal group.

Conclusions:

• Cataract surgery with CCIs effectively reduces N-CORA.
• While superotemporal and temporal incisions induce differential effects on oblique astigmatism meridians, they do not significantly impact the overall magnitude of corneal astigmatism.
• Incision placement choice may be considered for managing specific astigmatic components.