Introducing the 24-2C Visual Field Test in Neuro-Ophthalmology.

Abstract

The Humphrey 24-2C visual field test is a modified 24-2 visual field test that incorporates 10 additional test points in the central 10° of vision. This study compares the new 24-2C test to the standard Humphrey 10-2 visual field test in patients presenting for neuro-ophthalmology evaluation to evaluate its ability to detect central visual field defects. Twenty-five neuro-ophthalmology patients (42 eyes) underwent both 24-2C and 10-2 visual field testing using the Humphrey perimeter. The number of flagged total deviation (TD) and pattern deviation (PD) points of the 10 added test points of the 24-2C were compared with the corresponding 10-2 fields at the P < 5%, P < 2%, and P < 1% significance levels. The total number of flagged TD points were further analyzed by diagnosis. An experienced neuro-ophthalmologist evaluated all visual fields, commenting on the added value for clinical practice. There was no significant difference between the number of flagged TD and PD points of the 10 extra 24-2C points and corresponding 10-2 points at all significance levels. When analyzed by diagnosis, there was no significant difference in the number of flagged TD points in patients with optic neuritis, ischemic optic neuropathy, optic atrophy, and no neuro-ophthalmic disease. The added 24-2C points aided in identifying visual field defects and areas of spared central vision and had similar diagnostic value as the 10-2. The 24-2C is able to detect visual field loss in the central 10° that corroborates with loss detected in the 10-2 pattern. The 24-2C exhibits potential to be used as a hybrid between the 24-2 and 10-2 to better evaluate visual field defects.