• Four patients had relative afferent pupillary defects, asymmetric glaucomatous cupping of the optic nerve head, asymmetric intraocular pressure, and normal kinetic visual fields. The "Gunn pupil" can be a sign of early asymmetric glaucoma at a stage before visual field defects can be demonstrated by standard perimetry. Three other patients with afferent pupillary defects and asymmetric intraocular pressures and cupping showed early visual field defects only on repeated, refined perimetry. No visual field defects were found in five patients with asymmetric cupping and clinically normal pupillary findings.
Kohn AN, Moss AP, Podos SM. Relative Afferent Pupillary Defects in Glaucoma Without Characteristic Field Loss. Arch Ophthalmol. 1979;97(2):294-296. doi:10.1001/archopht.1979.01020010146010