Speaker - David Crabb 

Glaucoma poses a significant burden not only for patients and their families but also for hospitals and clinicians. It is estimated that around a million glaucoma appointments occur annually in the United Kingdom (UK). With an aging population, this issue has been persistent.

Managing the high volume of glaucoma patients often focused heavily on intraocular pressure (IOP), as it was the main modifiable risk factor. A study of 11 UK hospitals found that treatment intensification and monitoring frequency decisions were primarily driven by IOP rather than optic nerve assessments or perimetry. Despite this, visual field measurements were considered crucial for monitoring, as they directly reflect the patient's visual function. Interviews with glaucoma stakeholders and clinical trials emphasized that visual fields are a primary endpoint for evaluating new treatments, underscoring the importance of perimetry measurement.

Perimetry posed challenges for patients, as illustrated by particularly difficult visual fields. A study found that patients often struggled with visual field tests due to issues with supervision, noise, and testing environments, and many did not understand their results. Over the past 10 to 12 years, efforts have been made to develop a portable perimetry system intended to augment clinical practice. 

The initial version of the portable perimetry system, which used eye movements on a tablet and eliminated the need for button pressing, showed good agreement with traditional methods. Despite promising results published in a study, caution was advised when evaluating new techniques, as their real-world applicability was crucial. The system was subsequently tested in clinics and waiting rooms, demonstrating its effectiveness in screening patients who needed these visual fields.

Around 2019, a study explored the feasibility of patients performing visual field testing at home using a portable, inexpensive perimetry system. Based on a small tablet computer, this device used a button for a threshold test like full threshold tests. It incorporated advanced technology, including a webcam monitoring head position, and ensured patient reliability.

A study recruited 20 patients to test a portable perimetry system. Participants underwent standard visual field tests at the start, then used the portable device at home monthly for six months before returning for standard tests. The study assessed patient experiences with home monitoring, noting that some found frequent testing increased their anxiety about glaucoma. Despite these concerns, the data from home tests were reliable and comparable in quality to initial and final standard tests. The variability in test results from the home device was narrower than that from less frequent standard testing, suggesting that home monitoring could enhance the detection of progression in clinical trials by providing more precise measurements.

In the past four to five years, the perimetry system evolved from a tablet-based device to a set of glasses connected to a small phone. With UK approval secured, plans were made for the next set of studies, including extending perimetry into hard-to-reach communities like domiciliary care and international screening programs. The system was also set to be used in a clinical trial in Singapore investigating a new glaucoma treatment, nicotinamide, to explore how home visual field testing could enhance clinical trials.

A recent study published a month ago explored home monitoring by mailing patients a contrast sensitivity test. Approximately half of the patients completed the test before their clinical visit for cataract assessment. The results from the tests were closely aligned with the clinicians' evaluations of visual function. This study highlighted patients' willingness to self-test and invest in monitoring their health.

The issue of extending home monitoring for glaucoma to a wider patient demographic has been addressed. The study focused on highly motivated patients, termed "perimetry athletes," eager to engage in visual field testing and complete questionnaires. The challenge identified was reaching patients who were less proactive about managing their glaucoma. While the technological aspects of home monitoring remain relatively straightforward, integrating it into routine hospital services is the main difficulty. The patients involved in clinical trials are typically more invested in their care and thus better positioned to benefit from such technology. Hence, careful consideration of implementing home monitoring effectively for a broader range of patients in real-world settings can be warranted. 

42nd Congress of the European Society of Cataract and Refractive Surgeons, 6 – 10 September 2024, Fira de Barcelona, Spain.Top of Form