Pupillary membranes, bilateral

This code indicates the presence of persistent pupillary membranes affecting both eyes. These are remnants of the fetal pupillary membrane that failed to fully resorb, appearing as fine strands or webs across the pupil, often originating from the iris collarette. While usually benign, they can occasionally impair vision.

Use this code when documentation explicitly states the presence of pupillary membranes in both the right and left eyes. This diagnosis is typically made during an ophthalmological examination, where the membranes are observed. Supporting documentation should include findings from a slit lamp examination.

• Ensure the documentation clearly specifies involvement of both eyes; otherwise, use the appropriate unilateral code (H21.41 or H21.42).
• Do not confuse persistent pupillary membranes with synechiae (adhesions of the iris), which are coded differently (e.g., H21.5-).
• If the pupillary membranes are causing visual impairment, consider coding the associated vision problem as a secondary diagnosis.