Coding: Reimbursement for Managing Complications of Glaucoma Surgery

Ophthalmologists are among the most innovative physicians, and technological advances in ophthalmic surgery are numerous and sometimes astounding. However, with advances sometimes come unexpected problems. There have been many new products for minimally invasive glaucoma surgery (MIGS) going back to the early 2000s. Some did not withstand the test of time.

In light of the potential risk and benefits associated with surgery, surgeons must obtain informed consent from the patient prior to a proposed procedure.1 Anne M. Menke, RN, PhD, OMIC risk manager, advises, “First, personally obtain the patient’s informed consent. This legal duty cannot be delegated. During the discussion and documentation process, it is crucial to explain the effect of ocular and medical comorbidities and other known risk factors on the likelihood of complications during and after the procedure and on the final outcome. Use a procedure-specific consent form.”2 Although the patient and surgeon enter the operating room with the expectation of a successful procedure, there are always risks. Fellman et al wrote, “Glaucoma surgery is high risk compared to many other eye procedures.”3 Feldman and Bell state, “Glaucoma surgery is difficult and fraught with complications. Some complications are common and mild, while others are rare and/or vision threatening. However, good outcomes are still likely if those complications encountered are managed properly.”4

Complications are managed in different ways, and reimbursement for that management varies. The Centers for Medicare & Medicaid Services (CMS) publishes detailed and accessible instructions on this topic;5 other third-party payers often follow those regulations but are not obligated to do so. Experience teaches us that opaque or missing third-party payer instructions are not generally friendly to physicians, and they only obscure the billing process and result in a delay or denial of reimbursement.

Most care within the postoperative period is incorporated in the Medicare reimbursement for the surgeon’s major surgical procedure and not separately billable. CMS specifically includes the following within the global surgery package:

  • “All additional medical or surgical services required of the surgeon during the post-operative period of the surgery because of complications, which do not require additional trips to the operating room;”
  • “Follow-up visits during the post-operative period of the surgery that are related to recovery from the surgery;” and
  • “Supplies except for those identified as exclusions.”6

In the context of glaucoma surgery, examples include changing postoperative medications, paracentesis at the slit lamp to rapidly lower intraocular pressure, Carlo Traverso maneuver (a test for bleb function), injection of viscoelastic into the anterior chamber for hypotony and flat anterior chamber, supply of viscoelastic for this injection, or unplanned subconjunctival injections of 5-FU near the bleb following trabeculectomy. All of these related services do not require a return to the operating room and are performed in the office by the surgeon. Care that occurs outside of the postoperative period is not part of the surgeon’s Medicare reimbursement for the major procedure. It is separately billed and reimbursed according to the Medicare Administrative Contractor’s coverage and payment policies.

Some care that occurs within the postoperative period is not included in the global surgical package and is likewise separately billed, including the following:7

  • “Visits unrelated to the diagnosis for which the surgical procedure is performed, unless the visits occur due to complications of the surgery;”
  • “Treatment for the underlying condition or an added course of treatment which is not part of normal recovery from surgery;”
  • “Clearly distinct surgical procedures during the postoperative period which are not re-operations or treatment for complications;”
  • “Treatment for postoperative complications which requires a return trip to the operating room (OR). An OR for this purpose is defined as a place of service specifically equipped and staffed for the sole purpose of performing procedures. The term includes a cardiac catheterization suite, a laser suite, and an endoscopy suite. It does not include a patient’s room, a minor treatment room, a recovery room, or an intensive care unit;”
  • “If a less extensive procedure fails, and a more extensive procedure is required, the second procedure is payable separately;” and
  • “Diagnostic tests and procedures, including diagnostic radiological procedures.”

In the context of glaucoma surgery, examples include return to the OR for surgical revision of a bleb, to recanalize an occluded microstent using an Nd:YAG laser, for trabeculectomy with mitomycin C following failed primary tube shunt, or for needling and repositioning of a Xen gel stent; B-scan ultrasound to locate a misplaced or dislodged glaucoma stent device, or for eye exam for evaluation and management of either glaucoma in the unoperated eye or age-related macular degeneration in the operated eye. It is noteworthy that diagnostic tests performed to confirm the expected results of the surgery are considered to be part of routine postoperative care and not billed separately, while tests to evaluate and plan management of complications are billed separately.

Various modifiers are used on claims for reimbursement for services that occur during the global surgery period. While a detailed explanation is beyond the scope of this article, the most common modifiers used in these situations are as follows:

  • Modifier 24: unrelated evaluation and management service by the same physician or other qualified health care professional during the postoperative period;
  • Modifier 58: staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period;
  • Modifier 78: unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period; or
  • Modifier 79: unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period.

All of the above is relevant to recent news. On September 14, 2018, the US Food & Drug Administration (FDA) issued a safety communication regarding the Alcon CyPass Micro-Stent “… to alert eye care providers and patients of the risk of eye damage in people who have the device implanted.”8 The risks are primarily related to endothelial cell loss. In response, the American Society of Cataract and Refractive Surgery (ASCRS) published a preliminary consensus statement on monitoring and treatment.9 The recommendations, with some caveats, include diagnostic monitoring using slit lamp examination (part of an office visit), gonioscopy (CPT 92020), ultrasound corneal pachymetry (optional for quantification; CPT 76514), or specular microscopy (optional for quantification; CPT 92286).

Monitoring is likely to continue indefinitely. Importantly, only about 30% of patients implanted with the CyPass device will experience endothelial cell loss, so a slit lamp examination may be the only medically necessary service. Surgeon discretion applies to the other recommended diagnostic tests; probably there is some motivation to perform these services even if reimbursement is not available. When the CyPass is not optimally positioned and in close apposition to the cornea, there is a greater concern that endothelial cell loss may occur, potentially leading to corneal decompensation. The ASCRS consensus states, “Gonioscopy should be performed on patients with an indwelling CyPass device with attention to device position - the presence or absence of contact between the corneal endothelium and the CyPass device, the position of the device lumen anterior to Schwalbe’s line, and to the number of retention rings visible in the anterior chamber.” Gonioscopy in glaucomatous patients is widely recognized as an element of the standard of care in the American Academy of Ophthalmology (AAO) Preferred Practice Patterns on this topic.10 It is expected that gonioscopy in these patients at appropriate intervals would be a covered service when performed and properly documented. Baseline cell count measurements and ultrasound corneal pachymetry of all patients implanted with the CyPass are screening and subject to Medicare’s limited coverage criteria.11 Specular microscopy in patients who exhibit corneal pathology is generally covered at reasonable intervals related to disease progression.12

The ASCRS preliminary consensus also cites the CyPass Micro-Stent instructions for use, which state, “…in the absence of clinical sequelae, device adjustment or removal is not recommended.”13 The ASCRS consensus is, “If corneal decompensation develops and >1 ring of the device is visible, the surgeon may consider CyPass repositioning, removal, or proximal end trimming. It was the consensus of the group that implant repositioning, ie, deeper implantation, would be most safe if performed within 7-10 days of implantation. Beyond this time period, there was concern expressed by the group that fibrosis around and/or through the filtration holes of the device may create a higher risk of complications with device repositioning. … Trimming of the proximal end is likely to be the preferred procedure if the patient and the physician desire intervention.”

Because repositioning and removal of the CyPass are not encouraged after 7-10 days, they might never be performed or deferred until the 90-day global period for concurrent cataract surgery is passed. The AAO stated in a fact sheet that volume will likely be low and that the safest course for a well implanted device is monitoring.”14 As mentioned earlier, care that occurs outside of the postoperative period is not part of the surgeon’s Medicare reimbursement for the major procedure. Special modifiers listed above are only needed on claims for services within the 90-day global period.

If an intervention becomes necessary, it may be reported on a claim for reimbursement as follows:

  • Repositioning: Use CPT 66999 (unlisted procedure, anterior segment of eye)
  • Removal: Use 65920 (removal of implanted material, anterior segment of eye)
  • Trimming (ie, partial removal): Use 65920 (removal of implanted material, anterior segment of eye).14

Unlike repositioning an intraocular lens (CPT 66825) and revision of aqueous shunt (CPT 66184, 66185), there is no unique CPT code to describe repositioning of a MIGS device, such as the CyPass Micro-Stent, hence an unlisted procedure code is the only option to report the procedure on a claim for reimbursement. CPT further instructs, “For use of ophthalmic endoscope with 65920, use 66990.”15 There is no additional Medicare reimbursement to the ambulatory surgery center (ASC) or hospital outpatient department (HOPD) for 66990 although there is a small additional reimbursement to the surgeon ($92.52 in CY 2018). There is no Medicare reimbursement to an ASC for any unlisted procedure code (eg, 66999), although there is reimbursement to the HOPD for 66999 under APC 5491 ($1,921.09 in CY 2018).

The circumstance that could lead to repositioning, removal, or trimming is a malpositioned CyPass Micro-Stent touching the endothelium, resulting in corneal decompensation. In ICD-10, “protrusion” of an ocular prosthetic device is codified as T85.398 (other mechanical complication of other ocular prosthetic devices, implants and grafts), while “displacement” is codified as T85.328 (displacement of other ocular prosthetic devices, implants and grafts). ICD-10 further instructs, “These codes should be sequenced first, followed by a code(s) for the specific complication, if possible.”16 A number of possible ICD-10 codes could apply; give some consideration to the H18 section (other disorders of cornea); a likely choice is H18.1x (bullous keratopathy).

The beginning of the T85 section in ICD-10 states that the appropriate seventh character should be added to each code from category T85: “A” for initial encounter, “D” for subsequent encounter, and “S” for sequela. The preface to this section, under definitions, explains how to make the selection. “A” is used for each encounter where the patient is receiving active treatment for the condition. In this context, “condition” means the displaced or protruding device. “D” is used for encounters after the patient has completed active treatment and is receiving routine care during recovery. “S” is used when sequelae arise as a direct result of the condition. In this case, corneal decompensation is the sequelae to a displaced or protruding device, and the likely treatment is keratoplasty. The seventh character “S” is appended to the appropriate T85 code to identify that it is the cause of the sequela.

It is important to note that for most patients, while the surgeon is monitoring their progress, and the CyPass Micro-Stent is in good position and there is no corneal touch or decompensation, the selection of appropriate ICD-10 codes will include only those related to glaucoma (H40.-), pseudophakia (Z96.1), presence of other functional implants (Z96.-), pertinent comorbidities, and not T85.-. Here, the hyphen after the decimal means that additional characters are needed and the coder should refer to the ICD-10 manual to make the proper choice.

Even when the initial glaucoma surgery is not covered by Medicare for any reason, the treatment of medical and surgical complications is considered medically necessary and, therefore, is covered when, if left untreated, the complication would endanger the health of the individual. For example, treatment of an infection at the surgical site of a noncovered service is covered.17 Other third-party payers have similar policies.18,19


All surgical procedures have the potential for complications, and Medicare and other third-party payers cover and pay for the evaluation and management of those events either as part of the global surgery package or in addition to it if it arises within the global surgery period. Late-onset complications outside of the global surgery period are likewise covered and reimbursed subject to the limitations of local and national coverage determinations. Even complications after noncovered surgery are usually covered. With the surprise withdrawal of the CyPass Micro-Stent from the market due to unexpected endothelial cell loss, the reimbursement considerations related to managing complications are immediate and relevant. GP


  1. The Joint Commission. Informed consent: more than getting a signature. Feb 2016. Available at: . Accessed October 16, 2018.
  2. Menke AM. PAM testing before cataract surgery. OMIC Digest. Summer 2003. Available at: . Accessed October 16, 2018.
  3. Fellman RL, Grover DS. 77 – Trabeculectomy. In: Glaucoma (Second Edition). 2015(2):749-780. Available at: . Accessed October 16, 2018.
  4. Feldman RM, Bell NP (eds). Complications of Glaucoma Surgery. New York: Oxford University Press; 2013.
  5. CMS Medicare Learning Network. Global surgery booklet. September 2018. Available at: . Accessed October 16, 2018.
  6. US Centers for Medicare and Medicaid Services. Components of a global surgical package. In: Medicare Claims Processing Manual. Chapter 12 §40.1A. Available at: . Accessed October 16, 2018.
  7. US Centers for Medicare and Medicaid Services. Services not included in the global surgical package. In: Medicare Claims Processing Manual. Chapter 12 §40.1B. Available at: . Accessed October 16, 2018.
  8. US Food and Drug Administration. Potential eye damage from Alcon CyPass Micro-Stent used to treat open-angle glaucoma: FDA safety communication. September 14, 2018. Available at: . Accessed October 16, 2018.
  9. ASCRS CyPass Withdrawal Task Force. Preliminary ASCRS CyPass withdrawal consensus statement. Available at: . Accessed October 16, 2018.
  10. American Academy of Ophthalmology. Primary open-angle glaucoma preferred practice pattern – 2015. Available at: . Accessed October 16, 2018.
  11. US Centers for Medicare and Medicaid Services. Your guide to Medicare’s preventive services. Available at: Accessed October 16, 2018.
  12. US Centers for Medicare and Medicaid Services. National coverage determination (NCD) for endothelial cell photography (80.8). Available at: . Accessed October 23, 2018.
  13. Alcon. Instructions for Use CyPass Micro-Stent, REF# CYP-241-S. Available at: . Accessed October 23, 2018.
  14. American Academy of Ophthalmology. 0474T CyPass fact sheet. October 16, 2018. Available at: Accessed October 23, 2018.
  15. American Medical Association. CPT 2018: professional edition. Author; 2017.
  16. US Centers for Medicare and Medicaid Services. 2018 ICD-10-CM official guidelines for coding and reporting. Available at: . Accessed October 23, 2018.
  17. US Centers for Medicare and Medicaid Services. Medicare learning network, items and services not covered under Medicare. January 2017. Available at: . Accessed October 16, 2018.
  18. Priority Health. Medical policy no. 91086-R5, complications to non-covered care. Available at: . Accessed October 16, 2018.
  19. Blue Cross Blue Shield of Rhode Island. Medical coverage policy, coverage of complications following a non-covered service. March 2015. Available at: . Accessed October 16, 2018.