Clinical application of full-arc, depth-dependent, astigmatic keratotomy

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Surgery

Background:

• Astigmatism is a common refractive error affecting visual acuity.
• Accurate correction of astigmatism is crucial for successful refractive surgery.
• Existing keratotomy techniques may have limitations in precision and predictability.

Purpose of the Study:

• To evaluate the initial clinical outcomes of a novel astigmatic keratotomy technique: full-arc, depth-dependent astigmatic keratotomy (FDAK).
• To assess the safety and efficacy of FDAK in correcting regular astigmatism.
• To investigate the relationship between incision depth and the degree of astigmatic correction achieved with FDAK.

Main Methods:

• Corneal topography was used to analyze astigmatism type.
• For regular astigmatism, paired arcuate incisions of 90 degrees length were employed.
• Incision depth was varied from 40% to 75% of corneal thickness to control correction levels.

Main Results:

• Thirteen cases of regular astigmatism were treated with FDAK.
• A dose-dependent effect was observed, with deeper incisions yielding greater astigmatic correction (0.93 D to 4.44 D).
• Postoperative astigmatism remained stable from 3 months to 1-3 years, with no significant regression.

Conclusions:

• FDAK demonstrates a predictable, near-linear correlation between incision depth and astigmatic change.
• The technique appears to be an effective and safe method for precise astigmatic correction.
• Further clinical studies are warranted to establish definitive conclusions and develop a nomogram for FDAK.