Anisometropia

Anisometropia is an ocular condition characterized by a significant difference in refractive error between the two eyes. This disparity means one eye is more nearsighted, farsighted, or astigmatic than the other, leading to unequal focusing power. It can result in blurred vision in one eye, amblyopia, or diplopia.

Use this code when documentation clearly indicates a diagnosis of anisometropia, meaning a measurable difference in refractive error between the patient's eyes. This diagnosis is typically made during a comprehensive eye examination with refraction. Supporting documentation would include ophthalmologist or optometrist notes detailing the refractive error for each eye and the resulting diagnosis.

• Differentiate from amblyopia (H53.0x), which can be a consequence of uncorrected anisometropia, but is a distinct diagnosis.
• Ensure the documentation specifies "anisometropia" rather than just different refractive errors, as the latter may not always meet the clinical threshold for this diagnosis.
• Consider laterality if specified, though H52.31 is a bilateral code. If only one eye is affected by a specific refractive error contributing to the anisometropia, code the specific refractive error for that eye in addition to H52.31.