APRIL 2020 | 19

COVER FOCUS A ROADMAP TO TREATING GLAUCOMA �

Despite diagnostic advances and expanding treatment options, glaucoma continues to chal-lenge eye care providers for many reasons. Adherence,

early detection, and mysterious patho-physiology remain problematic. As optometrists assume larger and more important roles in the management of glaucoma, it is important that they stay up to date on the techniques and technologies for treating this sight-threatening disease.

Microinvasive glaucoma surgery (MIGS) is a recent addition that can offer improved safety and earlier surgi-cal intervention in the disease process, in comparison with more invasive sur-gical procedures, to decrease patients’ dependence on medication. Pairing a MIGS procedure with cataract surgery makes sense because these pathologies

often occur at a similar age and the combination reduces the number of times a patient must undergo surgery.

Reimbursement considerations, however, complicate the situation. The FDA has approved four MIGS devices: the iStent Trabecular Micro-Bypass Stent (Glaukos), the iStent inject (Glaukos); and Hydrus Microstent (Ivantis), with labeling indicating that they are to be used in combination with cataract surgery in patients with mild to moderate glaucoma, and the Xen Gel stent (Allergan), which can be used in combination with cataract surgery or without cataract surgery, and is approved for use in patients with refractory glaucoma. In addition, the labeling of these devices states that patients must have been using ocular hypotensive medication.

In most circumstances, therefore, a glaucoma suspect would not qualify for reimbursement for one of these MIGS procedures.1-3 Optometrists therefore must think ahead strategi-cally in order to prepare patients and document the justification for a MIGS procedure so as to streamline the surgical consultation. Below are three steps to consider for patients whom you think may be candidates for a MIGS procedure.

STEP NO. 1: CATEGORIZE THE DISEASE

ICD-10 classification requires increased specificity regarding the type of glaucoma and its level of severity in comparison with the previous version, ICD-9 (see Categories of Glaucoma). The coding revision also increased specificity with regard to MIGS procedures and their indications,1,2 which has allowed payers to restrict reimbursement for specific glaucoma procedures

MANAGING GLAUCOMA IN 2020

Stay three steps ahead. BY JACOB LANG, OD, FAAO; AND LAURA CAPELLE, OD, FAAO

Figure. Gonioscopy image of iStent inject Trabecular Micro-Bypass System (Glaukos) in situ.

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� COVER FOCUS A ROADMAP TO TREATING GLAUCOMA

and devices to certain types of glau-coma and levels of disease severity. Optometrists must be aware of the indications for each MIGS procedure in order to recommend treatment that is appropriate for each patient.

STEP NO. 2: INITIATE THERAPYCurrent indications state that all

patients undergoing a MIGS pro-cedure must be using glaucoma medical therapy.1-3 For example, patients must be using at least one IOP-lowering drop before receiving the iStent Trabecular Micro-Bypass Stent (Figure). In contrast, to undergo surgery with the Xen Gel

Stent, patients must be on maximum tolerated medical therapy. Unlike the iStent, the Xen does not have to be combined with cataract surgery.

These requirements suggest that it may be prudent to initiate medical therapy sooner than has been com-mon practice. Starting topical therapy when a patient is first diagnosed with glaucoma opens the door to a MIGS procedure if and when it is indicated.1

STEP NO. 3: DOCUMENT TREATMENT FAILURE

Treatment failure can be used to justify a recommendation for MIGS. Examples include uncontrolled

IOP, an intolerance of topical drops because of allergy, and other barriers to medical therapy (eg, poor com-pliance, ocular surface toxicity and other side effects, financial burden).1-3

IT PAYS TO THINK AHEADTo quote the English politician

Charles Buxton, “In life, as in chess, forethought wins.” Optometrists best serve their patients with glauco-ma by thinking ahead to treatments they may require in the future. To maximize their options, eye care providers can consider the benefits and drawbacks of initiating topical medical therapy early in the course of the disease, document glaucoma severity and treatment failures, and include MIGS in discussions with patients regarding alternatives for glaucoma treatment, particularly if cataract surgery is warranted. n

1. Local Coverage Article: Billing and Coding: Micro-Invasive Glaucoma Surgery (MIGS) (A56866). American Medical Association; 2019:1-8. www.aao.org/Assets/272e62d4-63e5-4245-9512-97b4b4abaf88/637021822352670000/palmetto-a56866-migs-updated-08072019-effective-08152019-pdf. Accessed February 26, 2020.2. Local Coverage Determination (LCD): Micro-Invasive Glaucoma Surgery (MIGS) (L37244). American Medical Association. 2018. www.aao.org/Assets/24d0a039-d828-4ad9-83f0-71c3324fe7fb/636776311207900000/ngs-l37244-migs-updated-11022018-effective-11082018-pdf?inline=1. Accessed February 26, 2020.3. Sheheitli H, Tirpack AR, Parrish RK 2nd. Which patients would most likely to benefit: MIGS or MEGS, which one is it? Asia Pac J Ophthalmol (Phila). 2019;8(6):436-440.

LAURA CAPELLE, OD, FAAO n Optometrist, Associated Eye Care, New

Richmond, Stillwater, and Woodbury, Minnesotan lcapelle@associatedeyecare.comn Financial disclosure: None

JACOB LANG, OD, FAAO n Optometrist, Associated Eye Care, Stillwater

and Hudson, Minnesotan Member, Modern Optometry Editorial

Advisory Boardn jlang@associatedeyecare.com

GLAUCOMA SUSPECT1

Patient exhibits one or two of the following: • IOP above 21 mm Hg • suspicious or asymmetric cup-to-disc ratio greater than 0.2 • suspicious visual field defect on 24-2 test

MILD STAGE2

Patient has optic nerve changes consistent with glaucoma but has a full visual field.

MODERATE STAGE2

Patient has optic nerve changes consistent with glaucoma and a glaucomatous visual field defect in one hemifield that is not within 5° of fixation.

SEVERE STAGE2

Patient has optic nerve changes consistent with glaucoma and glaucomatous visual field defects in both hemifields that are within 5° of fixation.

1. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol. 2009;44 (suppl 1):S7-93. 2. ICD-10 Glaucoma Reference Guide. American Glaucoma Society and American Academy of Ophthalmology. 2015. www.aao.org/Assets/5adb14a6-7e5d-42ea-af51-3db772c4b0c2/636713219263270000/bc-2568-update-icd-10-quick-reference-guides-glaucoma-final-v2-color-pdf?inline=1. Accessed February 26, 2020.

CATEGORIES OF GLAUCOMA