With an aging population, being able to effectively manage glaucoma will become an even more important part of optometric practice than it is today. Thankfully, advances in diagnostic instrumentation have made identifying glaucoma suspects and managing glaucoma patients easier than it’s ever been.
First, we’ll start with strategies for screening for glaucoma and identifying glaucoma suspects and then we’ll explore how glaucoma patients can most efficiently be integrated into a primary care optometric practice. Note that some of this is instrumentation dependent, so you may need to adapt your strategies, depending on the technology in your office.
IDENTIFY GLAUCOMA SUSPECTS
It wasn’t that long ago when glaucoma was identified solely by elevated IOP. Today, advanced screening as part of a routine comprehensive eye and health exam can elicit glaucoma earlier in the disease process, before significant visual loss occurs. Fundus photography can be helpful in evaluating disc asymmetry and following changes in optic nerve morphology and cupping. Screening VF and OCT can be especially valuable in helping optometrists to find defects early in the disease process. Once a patient is identified as a glaucoma suspect, he is counselled regarding the potential seriousness of the disease and the need for more extensive testing to confirm the diagnosis and initiate effective treatment.
SCHEDULE A GLAUCOMA WORKUP
Once a glaucoma suspect is identified, the front-desk staff schedules the patient for a subsequent follow-up appointment. A thorough glaucoma workup requires additional time for more extensive testing and patient counselling. Patients with clear signs of glaucoma may be started on medication at the first visit, if appropriate. However, the actual workup is scheduled for a different day to separate the comprehensive examination billing from the medical glaucoma billing of the follow-up visit, as required by virtually all insurers. In our practice, we have found success with booking glaucoma suspects in 30-minute slots four to six weeks after the comprehensive examination.
STREAMLINE THE GLAUCOMA APPOINTMENT
In our practice, skilled technicians are trained to operate the glaucoma diagnostic devices and import imaging into the patient’s EHR for documentation:
- Blood pressure. When the technician calls the patient back and takes him to our pretesting room, this is the first test to occur. We use an automatic digital brachial cuff with heart rate, due to its simple use and reproducible results. Ours is mounted on the wall in our pretesting room. This is set to run while the technician enters the patient’s demographic information into our SD-OCT.
- OCT. This diagnostic device is easy to operate, and its normative databases are incredibly helpful, making orientation to the data fast. Change analysis function of subsequent testing allows for quick assessment of early changes in the structure of the optic nerve head with objective measurements of the thicknesses of the ganglion cell complex, retinal nerve fiber layers, cup-to-disc ratios, areas and volumes. Some of the OCT devices have a fundus camera integrated and will correlate OCT findings with a click on the fundus image. (A caveat: Most insurance plans don’t allow billing of fundus photos and an OCT on the same date of service without some hoops.)
- Pachymetry. We use our OCT to obtain a corneal thickness map, which removes the need for a separate piece of equipment and, thus, an extra step. Additionally, on hyperopic, or narrow-angle glaucoma, suspects, the technician can image the nasal, temporal, superior and inferior angles, making very narrow angles easy to identify prior to performing gonioscopy.
- Perimetry. The glaucoma patient is then moved to our dark testing room for automated threshold perimetry. We run short wavelength (blue-yellow) threshold perimetry on younger glaucoma suspects and standard threshold perimetry on older glaucoma suspects who may have the presence of some nuclear sclerosis.
- Standard entrance testing. Next, the technician places the patient in the exam room, updating health and medication history, performing the standard entrance testing or the Core Four (visual acuities, pupils, extraocular movements and confrontations), importing all testing imaging and then removing a tonometer probe from the peroxide bath, drying it and placing it on the device.
- Goldmann tonometry. When I enter the exam room, the first thing I do is take the patient’s IOPs, assuring him that the sodium fluorescein used will not dilate him. I prefer to review test findings with the patient directly from the instrument’s viewing interface on the exam room computer monitor rather than from the imported image files. I find this allows for a more in-depth analysis of the imaging and smoother patient communication. On a glaucoma suspect whom I have not yet begun therapy or one who I’ve prescribed a new treatment, I will schedule an IOP check for one month, monitoring every three months for the first year, then every four months if he remains stable on the current therapy. On glaucoma patients who are not responding well to treatment, I repeat the OCT and perimetry testing every six months or sooner, depending on the patients level of risk. On glaucoma patients in whom therapy has been initiated and are at goal, I repeat this testing annually.
Glaucoma Diagnostic Devices
- Tonometry (Haag-Streit, Lombart, ICare, Keeler, Marco, Reichert, Topcon, Zeiss)
- Pachymetry (Accutome, DGH, Haag-Streit, Keeler, Reichert, Tomey, Topcon, Zeiss)
- Corneal Hysteresis (Reichert)
- Perimeter (Essilor, Haag-Streit, Oculus, Reichert, Topcon, Zeiss)
- PERG (Diopsys)
- Fundus camera (Canon, CenterVue, Digisight, Essilor, Kowa, Nidek, Topcon, Volk, Zeiss)
- SD-OCT (Haag-Streit, Heidelberg, Optovue, Topcon, Zeiss)
- OCTA (Haag-Streit, Heidelberg, Optovue, Zeiss)
- OCT (Haag-Streit, Heidelberg, Nidek, Optovue, Topcon, Zeiss)
REAP THE REWARD
In the past, many optometrists were afraid of managing glaucoma patients. In fact, glaucoma patients diagnosed between 1965 and 1980 had a 25.8% chance of losing sight, while patients diagnosed between 1981 and 2000 dropped to 13.5%1. Advancements in early detection should increase our confidence in identifying and monitoring patients who have this potential sight-threatening disease. Managing glaucoma patients to maintain their vision and quality of life is one of the most rewarding things we can do in primary care practice. OM
- Malihi M1, Moura Filho ER1, Hodge DO2, Sit AJ. Long-term trends in glaucoma-related blindness in Olmstead County, Minnesota. Ophthalmol. 2014; 1: 134-41.