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Glaucoma Experts | Mar/Apr '22

Surgical Glaucoma Case Logging—and Lagging

Can the system catch up to the rapidly evolving space?

Of the countless responsibilities placed on ophthalmology trainees, the logging of their surgical cases is not the most glamorous, but few would deny its importance. Case log numbers reflect the opportunities afforded by a training program and the experience and hard work of a trainee. However, the current case logging system provided by the Accreditation Council for Graduate Medical Education (ACGME) does not accurately portray the surgical landscape for an ophthalmology resident, particularly within the subspecialty of glaucoma.


  • Case log numbers reflect the opportunities afforded by a training program and the experience and hard work of the trainee.
  • The current case logging system provided by the Accreditation Council for Graduate Medical Education may not accurately portray the surgical landscape for an ophthalmology resident, particularly within glaucoma.
  • Although the glaucoma surgical requirements for residency graduation should eventually include MIGS, a manageable first step is to add a distinct category for ab interno glaucoma procedures.


The two categories of glaucoma surgery that are tracked with minimum requirements are (1) glaucoma filtering procedures, generally referring to ab externo trabeculectomy, and (2) glaucoma shunting procedures, generally referring to the placement of an aqueous shunt (eg, Ahmed Glaucoma Valve [New World Medical], Baerveldt Glaucoma Implant [Johnson & Johnson Vision], and Molteno [Nova Eye Medical]). Collectively, these two categories comprise traditional glaucoma surgeries.1 The ACGME mandates that all ophthalmology residents perform at least five glaucoma filtering or shunting procedures as the primary surgeon before graduation.2

Despite their growing popularity, MIGS procedures are nowhere to be found on the list of surgical minimum requirements for US ophthalmology residents. Over the past decade, MIGS procedures ranging from the placement of a trabecular meshwork bypass device (eg, iStent [Glaukos] and Hydrus Microstent [Alcon]) to excisional goniotomy or trabeculotomy (eg, Kahook Dual Blade [New World Medical] and TrabEx [MicroSurgical Technology]) to 360º ab interno cannulation and viscodilation of Schlemm canal (eg, gonioscopy-assisted transluminal trabeculotomy [GATT] or Omni [Sight Sciences]) have gained popularity as surgical options for lowering IOP in eyes with open-angle glaucoma.3 Optimistically assuming that all procedures are accurately logged by residents in the first place,4 some MIGS procedures currently count toward the glaucoma filtering and/or shunting minimum requirement category, some can be tracked as “other glaucoma” but do not count toward the glaucoma filtering or shunting minimum requirements, and others cannot be tracked at all.

For example, a goniotomy is logged with Current Procedural Terminology (CPT) code 65820, which falls under the category of other glaucoma. For GATT, the 2020 American Glaucoma Society MIGS position paper recommended using CPT code 65820,5 yet the injection of an OVD into the Schlemm canal (eg, ab interno canaloplasty) is coded using CPT code 66174, which currently counts toward the glaucoma shunting procedure minimum requirement category. Therefore, at this time, performing five ab interno canaloplasty cases would allow a resident to meet the glaucoma filtering or shunting minimum requirements.

The classification of the iStent and Hydrus is the most perplexing. From the mid-2010s through the beginning of this decade, the CPT code associated with the implantation of these devices, 0191T, was included in the glaucoma filtering or shunting category at the resident’s discretion; a resident could therefore meet ACGME minimum requirements by implanting five of these devices and not performing a single trabeculectomy or aqueous shunt surgery, which is probably not how the glaucoma surgical minimum requirements were meant to be interpreted.

However, as of January 1, 2022, the CPT code for trabecular meshwork bypass devices is bundled with routine and complex cataract surgery—CPT codes 66989 and 66991—which are not tracked as far as the ACGME case logging website is concerned. As a result, the implantation of an iStent or a Hydrus, which previously counted toward the glaucoma minimum requirements, is not tracked under the larger umbrella of glaucoma procedures. On the other hand, the removal of an iStent or a Hydrus can be logged with CPT code 65235 (removal of foreign body from eye), which is tracked by the ACGME under the globe trauma category.


With the current system, it is impossible for educators and researchers to make heads or tails of the data on trainees’ collective experience with MIGS. Although a recent survey of US program directors showed that only 27% believed that MIGS should be a surgical requirement for graduation, 73% incorporated MIGS wet labs into their surgical curricula.6

The glaucoma surgical requirements should eventually include MIGS, but a manageable first step for the ACGME to take is to develop a distinct category for ab interno glaucoma procedures. This would recognize the hundreds of graduating ophthalmology residents each year who perform ab interno goniotomy, trabeculotomy, and canaloplasty procedures and insert ab interno trabecular bypass devices. Additionally, it would better delineate the scope of this evolving trend within the surgical glaucoma space. Then, depending on what the first few years of data show, the ACGME minimum requirements could evolve to include MIGS.


The surgical glaucoma landscape is changing rapidly. With a few key modifications, the ACGME case logging system could be updated to better reflect the current trainee experience.

1. Qiu M, Woreta FA, Boland MV. Microinvasive glaucoma surgery in US ophthalmology residency: surgical case log cross-sectional analysis and proposal for new glaucoma procedure classification. J Glaucoma. 2021;30(7):621-628.

2. Case log information: ophthalmology. ACGME. Accessed February 28, 2022. www.acgme.org/globalassets/PFAssets/ProgramResources/OPH_CaseLogInfo.pdf

3. Yang SA, Mitchell W, Hall N, et al; IRIS Registry Data Analytics Consortium. Trends and usage patterns of minimally invasive glaucoma surgery in the United States: IRIS registry analysis 2013-2018. Ophthalmol Glaucoma. 2021;4(6):558-568.

4. Qiu M, Boland MV, Woreta FA, Goshe JM. Deficiencies in ophthalmology residents’ case logging of glaucoma surgery. Ophthalmol Glaucoma. 2020;3(3):218-220.

5. Fellman RL, Mattox C, Singh K, et al. American Glaucoma Society position paper: microinvasive glaucoma surgery. Ophthalmol Glaucoma. 2020;3:1-6.

6. Yim CK, Teng CC, Warren JL, Tsai JC, Chadha N. Microinvasive glaucoma surgical training in United States ophthalmology residency programs. Clin Ophthalmol. 2020;14:1785-1789.

Jacob Kanter, MD
Mary Qiu, MD