Abstract
Purpose: :
To study the relations between differential light sensitivity (DLS) and two forms of structural measures of ganglion cells of the central retina in patients with glaucoma involving the central ten degrees of visual field: perifoveal FD-OCT Ganglion Cell Complex (GCC) thickness and temporal rim area (tRA) of the retinal nerve fiber layer.
Methods: :
One eye each was tested for 17 patients with open angle glaucoma involving the central ten degrees of visual field (range 48-84 years, mean 66.6 +/- 10.4), and 17 age-similar controls (range 51-82 mean 64.6 ± 9.9). GCC thicknesses of the superior and inferior perifoveal regions were measured using the Optovue FD-OCT macular EMM5 program. tRA was measured using the Heidelberg Retinal Tomograph (HRT III). DLS was measured using stimulus size III white-on-white (HFAII-i, Carl Zeiss Meditek), 10-2 SITA Standard algorithm. dB values were converted into linear units of differential light sensitivity (DLS) and averaged across locations corresponding to the perifoveal sectors of the FD- OCT (accounting for displacement of the Henle fibers), and locations corresponding to the temporal rim sector of the HRT. All measures were then expressed as a percent of mean normal, using a linear model of age effects.
Results: :
DLS v. GCC: For all patients, the mean DLS defect was significantly deeper than the mean GCC defect: superior DLS (mean ± SD: -59% ±32%) v. inferior GCC (-14% ±18%), t = -7.07, p < 0.0001; inferior DLS (-41% ± 25%) v. superior GCC (-8% ± 9%), t = -6.89, p < 0.0001.DLS v. tRAL: For 13 of 17 patients the DLS defects were deeper than the tRA defects. Mean DLS defect was slightly deeper (-43% ± 23%) than tRA defect, (-31%% ± 39%), although this did not reach significance (t= -1.5 p = 0.15).
Conclusions: :
DLS indices were abnormal more often than both GCC and tRA indices, and mean DLS defects were significantly deeper than GCC defects.
Keywords: perimetry • optic nerve