Tip of the Month
Publishing date: September 2019
Tip Editors: Frances Meier-Gibbons, Humma Shahid, Karl Mercieca, Francisco Goni
Tip reviewer: Roger Hitchings
The Science behind the Tip (1,2)
It is well-established that damage to macular retinal ganglion cells (RGCs) occurs early in glaucoma (1). Not testing for this damage may miss glaucoma with paracentral visual field defects. In a prospective study, 62% of eyes with early glaucoma and a normal 24-2 test had an abnormal 10-2 test based on cluster criteria (2).
Furthermore, 40% of glaucoma suspect eyes and 35% of ocular hypertensive eyes that were classified as normal on 24-2 testing had abnormal 10-2 tests (2). Only two of the 24-2 or 30-2 test locations fall within “macular vulnerability zone” – the highly susceptible part of the inferior macula associated with superior paracentral field defects (1).
Contributor: Anthony Khawaja, United Kingdom
1. Hood, D. C., Raza, A. S., de Moraes, C. G. V., Liebmann, J. M. & Ritch, R. Glaucomatous damage of the macula. Prog. Retin. Eye Res. 32, 1–21 (2013).
2. De Moraes, C. G., Hood, D. C., Thenappan, A., Girkin, C. A., Medeiros, F. A., Weinreb, R. N., Zangwill, L. M. & Liebmann, J. M. 24-2 Visual Fields Miss Central Defects Shown on 10-2 Tests in Glaucoma Suspects, Ocular Hypertensives, and Early Glaucoma. Ophthalmology 124, 1449– 1456 (2017).