|The type of VF test you perform on a patient may depend on the status of their ocular health. Photo: Danica Marrelli, OD. Click image to enlarge.|
Visual field (VF) loss in glaucoma is commonly found using differential light sensitivity thresholds, deviations and percentiles from static automated perimetry, in addition to a clinician’s subjective assessment. New research suggests that despite several existing benchmarks, some established criteria vary in sensitivity and specificity when evaluating VF damage.
The single-center study included 1,230 suspect or known glaucoma patients with reliable VF (Humphrey 24-2 SITA) and OCT (Spectralis) exams within a four-month period. The investigation included one eye per patient. The research team from Canada compared the sensitivities and specificities from five criteria across various levels of functional and structural glaucomatous damage.
In patients with less damage, they found the Hoddap-Anderson-Parrish 2 and United Kingdom Glaucoma Treatment studies had higher positive rates suggesting lower specificities, while the Glaucoma Hemifield Test, Foster and Low-pressure Glaucoma Treatment studies all had lower positive rates, suggesting higher specificities.
In patients with greater degrees of damage, Hoddap-Anderson-Parrish 2 and the United Kingdom Glaucoma Treatment studies had higher positive rates indicating higher sensitivities, while the Glaucoma Hemifield Test, Foster and Low-pressure Glaucoma Treatment studies all had lower positive rates, indicating lower sensitivities.
“Overall, our findings highlight the lack of criteria with a uniformly superior diagnostic performance compared with others,” the investigators wrote in their paper.
When choosing which VF criteria to use, one should consider the degree of damage anticipated and need for either better sensitivity or specificity, the researchers suggested. Additionally, more than one VF criteria can be used, and their results interpreted jointly, they added.
Stubeda H, Quach J, Gao J, et al. Comparing five criteria for evaluating glaucomatous visual fields. Am J Ophthalmol. October 12, 2021. [Epub ahead of print].