Internal ophthalmoplegia (complete) (total), left eye

This diagnosis code signifies a complete paralysis of the intrinsic muscles of the left eye, specifically the ciliary muscle and the iris sphincter. This results in a fixed, dilated pupil and an inability to accommodate (focus) vision in the affected eye. It indicates a total loss of function of these internal ocular structures.

This code is appropriate when documentation clearly states "complete" or "total" internal ophthalmoplegia affecting the left eye. It is typically used in cases of oculomotor nerve (CN III) palsy affecting the parasympathetic fibers, or pharmacological mydriasis and cycloplegia that is not expected to resolve quickly. Supporting documentation should include findings of a fixed, dilated pupil and absent accommodation on the left.

• Ensure the documentation specifies "complete" or "total" involvement; partial internal ophthalmoplegia would require a different code.
• Verify laterality is explicitly stated as "left eye" to avoid miscoding.
• Differentiate from external ophthalmoplegia, which involves the extraocular muscles and has distinct coding.