Decoding MIGS Coding

Minimally invasive glaucoma surgeries are becoming more common in the surgical management of glaucoma. A number of procedures are in development, and several currently FDA-approved. Each procedure is unique based on the mechanism of action and method of insertion: ab interno and ab externo. Just as unique is the coding that accompanies the comanagement of patients undergoing one of these procedures. A clinician’s first task is to remember the difference between an HCPCS level I code and a HCPCS level III code.

Mastering MIGS: Today and Tomorrow

In recent years, minimally invasive glaucoma surgeries (MIGS) have exploded onto the scene to help fill a gap in the glaucoma treatment algorithm. Traditionally, first-line therapy for primary open-angle glaucoma (POAG) relied on topical glaucoma medications or selective laser trabeculoplasty to lower intraocular pressure (IOP). If those treatment options didn’t work, the patient would be referred to a glaucoma surgeon to consider more aggressive filtration surgical procedures such as trabeculectomy or tube shunts. However, the majority of glaucoma patients in the average practice have neither completely mild nor advanced disease; rather, they lie somewhere in the middle. These patients are often taking multiple medications, are not ideally controlled and could benefit from a treatment modality more aggressive than topical medication, but less so than filtration surgery. This is where MIGS fit in.

Lymphocytes on the Loose

We all know the classic presentation of uveitis: cells and flare, pain, photophobia and reduced vision. But because a multitude of events can trigger such a response, we sometimes lose sight of how these processes occur and what they signify about our patient. The patient’s systemic and ocular health rely on you, the optometrist, to carefully and strategically undertake a systemic review and work-up of anterior uveitis (AU) patients, to investigate and potentially uncover, an infectious, autoimmune or inflammatory underlying etiology.

We now know that a properly executed work-up, combined with more recent and advanced diagnostic techniques, yields an underlying systemic diagnosis in 70% of cases. The need is clear for a careful ocular evaluation and review of histopathological and immunological mechanisms to further narrow down the systemic work-up.

Looking to the Future of Glaucoma Treatment

As far as we know, intraocular pressure (IOP) is the only modifiable risk factor with respect to altering glaucoma’s characteristic death of retinal ganglion cells. IOP quantifies the balance between aqueous humor secretion by the ciliary body epithelia and its drainage through the conventional, pressure-sensitive pathway and unconventional, pressure-insensitive or “uveoscleral” pathways. IOP will increase along with any resistance to aqueous outflow. This can result from age-related cellular dysfunction in the conventional outflow pathway or a normal outflow system unable to handle overproduction. Since altering other mechanisms in the pathophysiology of the disease is not possible without profound risk to the patient, lowing IOP is the only means of arresting disease progression. In the United States, the current guidelines for the initial intervention of newly discovered cases of primary open-angle glaucoma recommend a first-line approach with topical ocular hypotensives. To that end, three new agents that are under investigation aim to decrease IOP without upsetting the physiology. If successful, these medications could help keep the primary outflow pathway functioning.