Numerous factors drive the need for enhanced efficiency in OCT imaging for glaucoma, including:

• The large and growing percentage of patients with, or at risk for, sight-threatening glaucoma (See “Glaucoma: An Overview,” p. 28).
• The fact that all 50 states now enable doctors of optometry to diagnose and manage the disease.
• The widespread availability and adoption of OCT as a standard of care tool to aid in the identification and monitoring of glaucomatous disease (see “A Look at OCT,” p.29).
• The ever-present need for doctors and staff to function as efficiently in clinic as possible.

Here, we discuss six action steps that can accomplish this, while ensuring accurate diagnosis, appropriate management, and high-quality patient care.

1 CONSIDER TIME-SAVING FEATURES

A general understanding of various OCT instruments now commercially available, and the individual features they offer, is the first step to establishing clinic efficiency with OCT.

Some models can image both the anterior and posterior segments of the eye, as well as perform OCT-Angiography (OCT-A), among other functions. At a minimum, when contemplating the purchase or upgrade of an existing OCT to manage glaucoma, consider these important and/or potentially time-saving features:

• Ability to image the retinal nerve fiber layer, optic nerve head, macula, and ganglion cell complex (or equivalent).
• Option to assess the angle of the eye.
• Corneal pachymetry function.
• Progression analysis software, which enhances data interpretation.
• Simultaneous scanning of the optic nerve and retina, which speeds image acquisition.
• Possible incorporation of additional technology, such as fundus photography.
• Automated image capture functions, which reduce acquisition time.
• Device footprint relative to available clinic space and staff/patient accessibility. For example, is there an adequate, centrally located room that minimizes how far patients/staff need to walk? Or, will the location potentially bottleneck access to other ancillary testing equipment?

2 TRAIN STAFF

Staff should be intimately familiar with the overall operation of whichever OCT the practice utilizes. This includes image acquisition protocols, instrument settings, and common scan acquisition errors. The latter can include image inversion from having the instrument too far from the eye decentering the scan or truncating the tissue in the scan window, and motion artifact (Figure 1). Avoiding these errors altogether (or at least identifying them immediately, so scans can be repeated before entering the exam room) prevents the unnecessary duplication of testing, which frustrates patients and requires the additional time of doctors and staff.

In terms of how staff can acquire training, OCT manufacturers offer in-person seminars for doctors and staff at instillation, and there are ongoing live and/or pre-recorded webinars for further education and training.

Additionally, ODs can appoint one or more staff members who are particularly proficient at obtaining scans to train fellow staff (Figure 2). Also, they can share time-saving tips, such as instilling a drop of 2.5% phenylephrine to slightly enlarge a miotic pupil for scan acquisition, or an artificial tear to enhance image quality in a patient who has dry eyes.

3 DON’T FOCUS ON SCAN COLORS

There is the temptation to immediately focus on scan colors (typically red, yellow, and green) when interpreting OCT scans. However, doing so can easily lead to misinterpretation and further practice inefficiency.

For example, interpreting a “red” area in the retinal nerve fiber layer (RNFL) nasal quadrant as “glaucomatous change” can yield a misdiagnosis of glaucoma. Recall that superior temporal macular fibers enter the temporal aspect of the optic nerve head (ONH), while inferior and inferior temporal macular fibers enter the inferior aspect of the ONH. To accurately interpret the OCT, it’s important to analyze the proximity of the scan reference circle to the edges of the optic disc and to ensure it’s centered. This is because a large disc may be closer to the edge of the reference circle, while a small disc may be farther away, causing the large disc to incorrectly appear to have a more robust RNFL, and the small disc to appear to have a thin RNFL.¹

To avoid the temptation of focusing on scan colors, we suggest that doctors of optometry do the following to minimize the risk of misinterpretation:

• First assess scan quality and reliability using reliability indices unique to your OCT.
• Check for acquisition errors (detailed above).
• Know and consider the margin of error of your OCT (typically +/- 5 μm).
• Account for confounders. This is coincident pathology that may reduce scan quality/reliability (e.g., dry eye, corneal scars, cataracts (Figure 3), posterior capsular opacification etc.), or which may falsely increase (e.g., macular edema, epiretinal membranes) or falsely decrease (e.g., high myopia, posterior capsular opacification) RNFL thickness.

4 ESTABLISH SCAN-ORDERING PROTOCOLS

Having established scan-ordering protocols in place minimizes the risk of necessary testing not being scheduled or not being billed, and is, therefore, paramount to efficiency with OCT.

When patients are diagnosed with glaucoma or ocular hypertension (or are identified as a glaucoma suspect), the doctor, technicians, schedulers, check-out staff, and billers in the practice should all be on the same page regarding the timeframe for patient follow-up and in which order/at which visit various testing is normally ordered (e.g., VF, corneal pachymetry, OCT of the nerve/macula, etc.) to establish efficiency.

For example, for patients who have well-controlled glaucoma, their annual cycle of glaucoma exams and testing might be:

• Month zero. Dilated fundus exam with optic nerve photos.
• Month 3 to 4. Exam with OCT of the nerve/macula.
• Month 6 to 7. Exam with VF.
• Month 9 to 10. Exam with gonioscopy and OCT of the angles.

Frequency of testing and follow-up to be performed would then be adjusted based on risk of disease progression and/or the need to repeat unreliable/inconclusive tests. Protocols for glaucoma suspects would also include one-time pachymetry, and the timeframe and order of follow-up testing would be based on a patient’s risk factors and which test(s) provide the most clinically useful information.

Informing staff upfront of potential acquisition challenges when orders are made can also greatly increase efficiency (e.g., informing technicians a patient has dense cataracts ensures they don’t spend too much time troubleshooting a poor scan image that cannot be improved, etc.).

Regarding coding and billing, the medical record must include an order for obtaining an OCT, as well as adequate documented clinical justification for a diagnosis of glaucoma, glaucoma suspect, or ocular hypertension patient. Proper coding and billing practices prevent unnecessary and time-consuming claim denials, appeals, and audits.

Utilizing an EHR template and/or written orders can also assist staff in appropriate billing. We recommend doctors of optometry review their managed care contracts to verify, but carriers can allow for reimbursement of up to two OCT scans of each optic nerve per year for glaucoma, as well as an anterior segment OCT of the angle of the eye.

Also, ODs should remember that fundus photos and OCT of the optic nerve/retina are considered mutually exclusive imaging procedures of the posterior segment by many insurance carriers. Therefore, if performed on the same day, they may not both be reimbursed (typically only the higher-reimbursing procedure is).

Also, doctors of optometry should recall that OCT and VFs, for example, are subject to a multiple procedure payment reduction with some insurers. This means if done on the same day, the higher reimbursing procedure is fully reimbursed, while the lesser procedure’s technical component is reduced by a set amount.

Regardless of reimbursement status, however, standards of care should always be maintained in the provision of care to patients.

5 OPTIMIZE SCHEDULING

How OCT scans are scheduled can also impact clinic efficiency. We suggest ODs account for how long it takes staff to acquire scans on average, whether the number of OCTs scheduled on a given day should be capped based on staffing and schedules, whether non-emergent, unscheduled, same-day scans will be allowed, and whether multiple tests, such as OCT and VF, will routinely be scheduled the same day on the same patient. Prudent planning can avoid preventable workup bottlenecks.

Of Note: On days a doctor may not be in the office (e.g., when a scheduled vacation is planned), OCTs, as well as other testing, such as VFs, can still be scheduled. This can be an efficient use of clinic time, generates revenue when the doctor is out, and allows staff to refine their OCT techniques. We have found that many insurers allow a level 1 exam to be billed for the time technicians spend with the patient, in addition to the testing itself. Patients can then be scheduled for a follow-up appointment when the doctor returns to clinic to assess their IOP and review the test results (or results may be reviewed via a telehealth visit).

Once an OCT is ordered, having a separate master testing schedule avoids bottlenecks. Further, for follow-up visits in which scans are to be performed in conjunction with an exam, we have found that having patients arrive for testing 20 to 30 minutes prior to their exam time enhances patient flow.

6 USE VISUAL AIDS FOR PATIENT EDUCATION

Communicating OCT results to patients can be time-consuming. Thus, once clinical interpretation of the data is completed, we suggest ODs consider referencing the color-coded visual aids (i.e. red, yellow, green) on the test results, progession analysis curves, and/or temporal, superior, nasal, inferior, temporal curves to facilitate efficient patient education. This can be accomplished using an exam room monitor or printout.

Additionally, technicians having scan results available for the doctor prior to entering the exam room can greatly expedite the communication of results.

DEALING WITH THE PRESSURE

Numerous factors, such as the number of glaucoma patients, are driving the need for enhanced efficiency in OCT imaging. The six action steps illustrated in this article should streamline patient care, creating efficiencies everyone involved. OM

References 
References:
 
1. Rao HL, Pradhan ZS, Suh MH, Moghimi S, Mansouri K, Weinreb RN. Optical Coherence Tomography Angiography in Glaucoma. J Glaucoma. 2020 Apr;29(4):312-321. Doi: 10.1097/IJG.0000000000001463.
 
2. BrightFocus Foundation. Glaucoma: Facts and Figures. https://www.brightfocus.org/glaucoma/article/glaucoma-facts-figures. Accessed January 5, 2023.
 
3. Fujimoto JG, Pitris C, Boppart SA, Brezinski ME. Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy. Neoplasia. 2000; 2(1-2):9-25. Doi: 10.1038/sj.neo.7900071.

DR. WROTEN is a partner at the Bond-Wroten Eye Clinics, a three-location private practice in southeast Louisiana, where he oversees its residency in primary care & ocular disease. He has lectured extensively and authored numerous articles on a variety of eye care topics.

DR. WARNOCK is a 2022 graduate from Southern College of Optometry and is currently completing a primary care/ocular disease residency at Bond-Wroten Eye Clinics in southeast Louisiana.