Posterior synechiae (iris), unspecified eye

This code signifies an adhesion between the iris and the anterior lens capsule, occurring at the posterior surface of the iris. This condition can impede pupillary dilation and may be a sequela of inflammation (uveitis) or trauma.

Apply this code when documentation specifies posterior synechiae of the iris without indicating laterality. This diagnosis is often made during a slit lamp examination. Use when the physician's notes confirm the presence of this adhesion but do not specify whether it affects the right or left eye.

• Avoid using this code if the laterality (right or left eye) is documented; instead, use the more specific codes H21.541 or H21.542.
• Consider coding any underlying cause, such as uveitis (H20.-), if documented and actively treated.
• Ensure the documentation clearly states "posterior synechiae" to differentiate from anterior synechiae (H21.53-).