Management of irregular astigmatism

Area of Science:

• Ophthalmology
• Optometry
• Corneal Science

Background:

• Corneal irregularity, including primary irregular astigmatism, is prevalent, with videokeratoscopy identifying it in approximately 40% of normal corneas with toric refractive error.
• Secondary irregular astigmatism arises from various factors such as corneal surgery, trauma, dystrophies, and infections.
• Noncorneal astigmatism, including lenticular astigmatism, also contributes to the overall refractive irregularity of the eye.

Purpose of the Study:

• To review the current understanding and management of irregular astigmatism.
• To discuss the evolving treatment options, particularly excimer laser ablations.
• To explore the integration of diagnostic technologies for optimal refractive outcomes.

Main Methods:

• Review of current literature on corneal irregularity and astigmatism.
• Analysis of videokeratoscopy findings in normal and irregular corneas.
• Discussion of advanced diagnostic and treatment technologies, including topographic analysis, wavefront analysis, and vector planning.

Main Results:

• Videokeratoscopy may overestimate primary irregular astigmatism in normal corneas.
• Tailored corneal excimer laser ablations offer improved treatment options.
• The optimal corneal shape and systematic treatment approaches remain subjects of ongoing discussion.

Conclusions:

• Integrated use of topographic analysis, wavefront analysis, and vector planning is crucial for refining refractive techniques.
• Ablatable polymer techniques show potential for managing irregularly roughened corneas.
• Further research is needed to establish definitive systematic approaches for optimizing the ocular optical surface.