Irregular astigmatism, unspecified eye

This code signifies an uncorrected refractive error where the cornea or lens has an uneven curvature, leading to distorted or blurred vision. Unlike regular astigmatism, the principal meridians are not perpendicular, or the curvature changes irregularly across the surface. This condition affects the eye's ability to focus light uniformly onto the retina.

Use this code when documentation specifies irregular astigmatism without further detail regarding the affected eye. This is appropriate when the ophthalmologist or optometrist diagnoses irregular astigmatism but does not specify if it's unilateral or bilateral, or if the laterality is unknown. Supporting documentation would include findings from topography or keratometry indicating an irregular corneal surface.

• Only use this code when laterality is truly unspecified; avoid using it if documentation clearly indicates a specific eye.
• Distinguish from H52.20 (unspecified astigmatism) which does not specify the type of astigmatism.
• Review documentation for underlying causes of irregular astigmatism, such as corneal scarring, keratoconus, or post-surgical complications, and code those conditions first if applicable.