Which comes first in glaucoma progression: structural loss or functional deficit? If you know that, investigators say, you’ll know which tests to administer.

Turns out, you need both, according to a prospective study in the online version of September’s Investigative Ophthalmology and Visual Science.

Investigators in New York followed 33 glaucoma patients with a battery of tests: frequency doubling perimetry, 24-2 Humphrey visual fields, multifocal visual evoked potentials, optical coherence tomography, as well as stereo-photographs of the optic disc.

Each test showed evidence of progression in some eyes. “However, agreement among tests and stereo-photography regarding which eyes showed progression was poor, illustrating the importance of following patients with a combination of functional and structural tests,” the investigators concluded.¹

This conclusion reflects a study in last year’s Optometry, which found that “tests of both structure and function are recommended in glaucoma suspects and patients, as neither mode is capable of identifying all glaucomatous deficits.”²

1. Xin D, Greenstein VC, Ritch R, et al. A comparison of functional and structural measures for identifying progression of glaucoma. Invest Ophthalmol Vis Sci. 2010 Sep 16. [Epub ahead of print].
2. Sherman J, Slotnick S, Boneta J. Discordance between structure and function in glaucoma: Possible anatomical explanations. Optometry. 2009 Sep;80(9):487-501.