Examining both the peripheral visual field and the central visual field improves detection of early vision loss in glaucoma, researchers found in a study published in BMC Ophthalmology. They also found a moderate correlation between the isopter area and mean sensitivity (MS).
Prior research has indicated peripheral kinetic visual field perimetry enables ophthalmologists to quickly detect peripheral visual field defects and central static automated perimetry (SAP) provides more reproducible and sensitive detection. The investigators believe theirs is the first study to evaluate the relationship between isopter area and SAP.
The researchers compared the success of central static and peripheral kinetic visual field tests of the vision of patients with primary open-angle glaucoma (POAG). They used SAP and peripheral visual field tests to evaluate 167 eyes of 89 patients (48 men) with suspect glaucoma or POAG. Peripheral kinetic visual field tests took significantly shorter time (median 71 seconds) compared with central static visual field tests (median 803 seconds P <.001).
They found glaucomatous defects in the peripheral visual fields of 18% of the 99 eyes with normal central visual fields. Patients with mild defects in the central visual field included 32 with normal isopters, 3 with localized defects in the central visual field tests and diffuse defects in peripheral visual field tests, and 10 cases with localized defects in both central and peripheral tests. The researchers identified 3 eyes with nearly normal peripheral isopters and 19 whose peripheral tests supported the diagnosis from central tests among the 22 with moderate to severe central visual field defects.
MS was also correlated with isopter area (rs = 0.494, P <.001).
“Our study demonstrated the diversity of glaucomatous visual field defects, as well as the possibility of losing the clinically valuable information due to focusing on the central visual field test alone,” investigators report. “The peripheral kinetic perimetry is clinically feasible to complement the central static perimetry for a comprehensive assessment of visual function in glaucoma patients.”
The study was limited by lack of correction of isopters for reaction time.
Ma X, Tang L, Chen X, Zeng L. Periphery kinetic perimetry: clinically feasible to complement central static perimetry. BMC Ophthalmol. Published online September 23, 2021. doi:10.1186/s12886-021-02056-5