Primary hypotony of unspecified eye

This code describes a condition where the intraocular pressure (IOP) in the eye is abnormally low, without an identifiable secondary cause such as trauma, surgery, or inflammation. It signifies a primary, idiopathic reduction in the fluid pressure within the eyeball, affecting the unspecified eye.

Use this code when documentation explicitly states "primary hypotony" or "idiopathic hypotony" and does not specify laterality (right or left eye). This diagnosis is typically made after ruling out other potential causes of low IOP.

• Ensure documentation specifies "primary" or "idiopathic" hypotony; otherwise, a secondary hypotony code may be more appropriate.
• Avoid using this code if the laterality (right or left eye) is documented; instead, use the more specific codes for right (H44.441) or left (H44.442) eye.
• Do not confuse with ocular hypotony due to other disorders (H44.40-H44.43) or hypotony of ciliary body (H21.24-).