Abstract
Purpose: :
To determine the prevalence and nature of visual field (VF) defects in the central 10° in glaucoma suspects (GS) and glaucoma patients using a prospective design.
Methods: :
Glaucoma patients and GS with a 24-2 VF test (HFA, Zeiss, Inc) with a mean deviation (MD) better than -6dB were enrolled and tested with a 10-2 VF. Eyes were excluded from the study if either test was unreliable (fixation loss>33%, false positive or false negative>20%). The VF of the 66 eyes (50 patients) meeting these criteria were classified as abnormal if they had a cluster of at least 3 contiguous points (5%, 5%, 1% or 5%, 2%, 2%) on either the total deviation or pattern deviation plot. After adjusting the 10-2 test points to take into consideration the location of the ganglion cells,[1,2] the pattern of abnormal points was categorized as consistent with an arcuate-like nerve fiber bundle defect, a diffuse defect, or other.
Results: :
There were nearly as many abnormal 10-2 VFs (66 hemifields, 46 eyes) as abnormal 24-2 VFs (68 hemifields, 45 eyes). Of the 64 normal hemifields on the 24-2 test, 10 (~16%) were abnormal based on the 10-2 test. [A similar number (~18%) of hemifields with normal 10-2 tests were abnormal on the 24-2 test.] Of the 66 abnormal hemifields on the 10-2 test, 43 (~65%) were consistent with an arcuate-like nerve fiber bundle defect. Of the remaining 23 abnormal hemifields, 8 were diffuse and 15 other (e.g. temporal defect or scattered points).
Conclusions: :
The 10-2 VF was abnormal in about as many eyes/hemifields as was the 24-2 VF [3], including 16% of the hemifields with normal 24-2 tests. The majority of the 10-2 VF abnormalities were consistent with an arcuate-like nerve fiber bundle defect. For glaucoma screening, both the 10-2 and 24-2 tests, or a customized pattern that combines the 6° grid of the 24-2 with a greater number of points in the central 10°, should be used.[4] 1. Hood DC et al. IOVS 2011, 940-946; 2. Drasdo N et al. Vision Res 2007, 2901-2911; 3. Langerhost CT et al. Perimetry Update 1996/1997, 67-73; 4. Schiefer U et al, IOVS 2010, 5685-5689.
Keywords: visual fields • macula/fovea • nerve fiber layer