ICD-10-PCS Billable Code

08123K4

Bypass Anterior Chamber, Right to Sclera with Nonautologous Tissue Substitute, Percutaneous Approach

Procedural Specifications

Clinical Axis Detail Definition
Section0 Medical and Surgical
Body System8 Eye
Operation1 Bypass
Body Part2 Anterior Chamber, Right
Approach3 Percutaneous
DeviceK Nonautologous Tissue Substitute
Qualifier4 Sclera

Operation Definition

Altering the route of passage of the contents of a tubular body part

Procedure Overview

This family covers procedures that create a new pathway for fluid within the eye, most often to manage glaucoma when standard treatments have not controlled eye pressure. The eye continuously produces a clear fluid called aqueous humor, and in glaucoma this fluid drains too slowly, building up pressure that can damage the optic nerve and threaten vision. A bypass procedure reroutes that fluid around the eye's natural, poorly functioning drainage angle to a new outflow location, typically by implanting a small tube or valve device that channels aqueous humor to a reservoir beneath the eye's outer surface.

Surgeons turn to these procedures, sometimes called glaucoma drainage device or aqueous shunt implantation, when medications and laser treatment have failed to keep pressure at a safe level, or when a patient's anatomy makes more conventional filtering surgery unlikely to succeed. The goal is not to cure glaucoma but to protect remaining vision by keeping pressure within a target range over the long term.

Anatomy & Axis Detail

Anterior Chamber, Right

The anterior chamber of the right eye is the fluid-filled space between the cornea and the iris through which aqueous humor circulates before draining at the trabecular meshwork, and its outflow pathway is the target of glaucoma surgery when medical therapy fails to control intraocular pressure. Bypass procedures here create a new route for aqueous drainage, most often using a minimally invasive glaucoma surgery device or tube shunt that channels fluid from the anterior chamber to the subconjunctival space, a collector channel, or an external reservoir, effectively rerouting flow around a diseased or resistant trabecular meshwork. Because the chamber angle is a delicate, image-guided surgical field visualized through a gonioprism, device selection and the specific drainage destination are critical to documentation, distinguishing procedures like trabecular micro-bypass stenting from tube shunt implantation.

Approach: Percutaneous

Percutaneous describes entry by needle or instrument puncture through the skin or mucous membrane to reach the site of the procedure, without cutting the tissue open or using a visualizing scope. It differs from Open in that the site itself is never exposed, and from Percutaneous Endoscopic in that no endoscope is used to see internal structures. Common examples include needle biopsies and injections.

Device: Nonautologous Tissue Substitute

Nonautologous Tissue Substitute refers to biologic material sourced from a donor or another species, such as an allograft or xenograft, used to replace a body part. It differs from Autologous Tissue Substitute by tissue origin outside the patient's own body, and from Synthetic Substitute by being biologic rather than manufactured material.

Qualifier: Sclera

This qualifier specifies the sclera, the tough white outer coat of the eyeball, as the structure involved when a procedure's qualifier needs to identify tissue beyond the primary body part, such as in repair or buckling procedures for retinal detachment. It is distinguished from other ocular qualifiers referring to structures like the conjunctiva or cornea.

Coding & Documentation

Code assignment hinges on the operative note specifying that a device was implanted to establish a new conduit for aqueous humor, along with the qualifier identifying where that fluid is being routed to, such as the subconjunctival space or an external collection reservoir. Documentation should also state which eye and, when relevant, which specific quadrant or structure served as the origin point of the bypass. A common assignment error is defaulting to a drainage or dilation code when the operative report actually describes a device creating a permanent alternate route rather than simply releasing trapped fluid or widening an existing passage. Coders should also confirm the device value matches what was actually implanted, since tube shunts and newer micro-stent devices are captured differently.

Commonly Confused With

DrainageThis family is frequently confused with Eye Drainage procedures, since both address excess intraocular fluid, but Drainage removes fluid without leaving a permanent rerouting device, while Bypass establishes an ongoing alternate pathway.
DilationIt also overlaps conceptually with trabeculotomy-type Dilation procedures that widen the eye's existing drainage angle rather than creating a new route entirely.