Real-World Evidence: Outcomes When Testing Frequency Increases

This audio article is from VisualFieldTest.com.Read the full article here: https://visualfieldtest.com/en/real-world-evidence-outcomes-when-testing-frequency-increasesTest your visual field online: https://visualfieldtest.comSupport the show so new episodes keep coming: https://www.buzzsprout.com/2563091/supportExcerpt:Real-World Evidence: Outcomes When Visual Field Testing Frequency Increases Visual field testing, also called perimetry, measures areas of vision that a person can and cannot see. It is especially important in glaucoma, because damage to the optic nerve may progress without noticeable symptoms until substantial vision has been lost. The practical question is not simply whether more tests produce more data. It is whether more frequent testing leads to earlier detection of true progression, better treatment decisions, preserved vision, and acceptable safety and workload. The current evidence suggests that increasing testing frequency usually improves the speed and precision of detecting visual field change. However, there is not yet strong proof that more frequent testing alone prevents blindness or improves quality of life. Evidence for home visual field testing used alongside clinic care is encouraging but still based mainly on small, selected studies rather than large comparative outcome trials. Key Findings at a Glance Clinic-based testing every six months detects progression earlier than approximately yearly testing, particularly when overall visual field trends are analyzed. In a large United States claims cohort, the median testing frequency was only 0.63 visual field tests per year, and more than three-quarters of patients had fewer than one test per year. Home testing can provide weekly or monthly measurements, reduce measurement noise, and sometimes identify a concerning change before the next planned clinic visit. Adherence is the main limitation. Short studies often report good participation, but longer studies show that testing frequency commonly declines over time. More frequent testing also produces more apparent progression signals, some of which later disappear. Confirmation rules are therefore essential. Direct evidence that increased testing changes long-term visual outcomes remains limited. Home testing should generally be treated as an adjunct to clinical examination, not a replacement for eye pressure measurement, optic nerve examination, imaging, and standard clinic-based perimetry. What Guidelines Recommend The European Glaucoma Society notes that there is still no definitive evidence showing which combination of tests or testing frequency produces the best patient outcomes at a sustainable cost. Nevertheless, it recommends obtaining enough early visual field measurements to estimate the individual rate of change. Newly diagnosed patients are often recommended to have standard automated perimetry approximately three times per year during the first two years, after which the schedule can be tailored to disease severity and observed progression. European Glaucoma Society guidelines The World Glaucoma Association similarly recommends an intensive early series in people at risk of visual disability. It suggests that lower-risk patients may later be tested about once a year, while higher-risk patients may need testing twice a year or more often if progression is suspected. World Glaucoma Association consensus These recommendations are based largely on the need to establish a reliable baseline and identify fast progression early. They should not be interpreted as a requirement for every patient to have the same schedule. Testing frequency should reflect: Existing visual field damage Rate of previous change Age and expected lifetime risk Whether the patient has only one useful eye Pressure control Optic nerve or retinal nerve fiber layer changes Presence of optic nerve hemorrhage Test reliability Patient ability to attend or complete testing How Often Are Patients Actually Tested? United States nationwide data A study of 380,029 people with open-angle glaucoma found that: 8.8% had no visual field test during the study period. 68.2% received fewer than 0.9 tests per year. Only 0.8% received at least 2.1 tests per year. The median testing frequency was 0.63 tests per year. The authors concluded that more than 75% of the population had fewer than one visual field test per year, which is below the frequency commonly recommended for many patients under active glaucoma monitoring. This study described healthcare delivery; it did not prove that increasing frequency would prevent vision loss. United States nationwide glaucoma cohort English hospital eye-service data A large electronic medical record audit evaluated 602,439 visual field records from 73,994 people across five glaucoma clinics in England. Among 25,760 patients with repeatable visual field loss: The median interval between visual field tests was 11.2 months. Approximately 4.6% of tests were classified as unreliable using the study’s reliability measure. The median rate of visual field change was approximately −0.21 decibels per year. About 24% of patients had advanced field loss at presentation. Differences in testing intervals and reliability were observed between clinics. This type of registry evidence is valuable because it reflects routine care rather than a highly controlled clinical trial. It also demonstrates how electronic records can monitor service quality, identify patients at risk, and measure whether a clinic is delivering testing consistently. English glaucoma visual field audit Outcomes When Clinic-Based Testing Frequency Increases Earlier detection of progression One of the clearest real-world analyses came from the Advanced Glaucoma Intervention Study. Researchers compared the original series of visual fields with a reduced-frequency series created by removing approximately every other follow-up test. The higher-frequency series had a median of 20 tests, compared with 12 tests in the lower-frequency series. Using a global measure called mean deviation: Progression was detected in 43.6% of eyes with the higher-frequency data. Progression was detected in 34.2% of eyes with the lower-frequency data. The higher-frequency series was about 69% more likely to identify progression using the mean deviation analysis. Using a point-by-point analysis, progression was detected in 39.5% of eyes with higher-frequency data versus 35.7% with lower-frequency data. The higher-frequency series was still more likely to detect progression, although the difference was smaller. Advanced Glaucoma Intervention Study frequency analysis This is important, but it must be interpreted correctly. The study showed that more frequent testing detects statistical progression sooner. It did not show that the additional tests themselves slowed disease or preserved vision. It was also not a randomized trial of two separate monitoring programs; the lower-frequency series was created by deleting tests from an existing dataset. Six-monthly testing may be a practical compromise A longitudinal cohort study used data from 1,072 eyes of 665 patients to model how quickly different rates of glaucoma progression could be detected. For eyes losing approximately 2 decibels per year, a progression signal could be detected with 80% statistical power after approximately: 3.3 years with yearly testing 2.4 years with testing twice per year 2.1 years with testing three times per year For slower loss of approximately 0.5 decibels per year, detection took approximately: 7.3 years with yearly testing 5.7 years with twice-yearly testing 5.0 years with testing three times per year The improvement from yearly to twice-yearly testing was larger than the improvement from twice-yearly to three-times-yearly testing. The authors concluded that two reliable baseline tests followed by testing approximately every six months, with confirmation of suspected progression, may offer a practical balance between speed and burden. Longitudinal cohort study of visual field testing frequency Personalized schedules may be more efficient than fixed schedules A separate analysis using data from the Advanced Glaucoma Intervention Study and the Collaborative Initial Glaucoma Treatment Study evaluated a personalized testing model. The model increased testing when the patient’s previous results suggested a higher likelihood of progression and reduced testing when the disease appeared stable. Compared with a fixed yearly schedule, the model: Detected progression 57% sooner. Improved progression-detection efficiency by 29%. Did not require more visual field tests overall. This was a model based on previous clinical trial data rather than a prospective implementation study. It supports a risk-based approach, rather than testing every patient at the same frequency. Personalized glaucoma monitoring schedule study Frontloading tests may increase information without adding visits An emerging clinic-based strategy is to perform two visual field tests per eye during the same visit and use their average. A 2025 prospective study found that this “frontloaded” approach reduced variability in global and point-by-point measurements compared with using one test per visit. The average rate of progression was similar, but the estimates were more precise. Frontloaded visual field testing study This may be useful for patients who cannot perform home testing or who have difficulty attending additional appointments. Do More Tests Lead to More Treatment Changes? The clinical pathway A confirmed visual field decline may lead an eye specialist tSupport the show