Abstract
Purpose :
Our previous work affirmed that in glaucoma paired eyes and brain work together to maximize the binocular field, avoiding overlapping areas of visual loss (the Jigsaw Effect; TVST 2013,14). We also observed that among glaucomatous eyes with either high(85%; Hc) or low(15%; Lc) contrast VEP latency in each eye showed a strong inverse relationship (P=0.0000003) between Hc and Lc latency between the paired eyes, presumably conserving binocular dynamic function (Ly et al ARVO 2017). We sought to determine whether central vs midperipheral visual field loss tended to correspond with bilateral Hc/Lc functional bias.
Methods :
30 paired glaucomatous eyes that each demonstrated either Hc or Lc latency abnormality on SD-tVEP (Diopsys, Inc, Pine Brook, NJ) underwent masked assessment of recent paired visual fields (HVFA or FDT) to determine whether field loss was dominantly central (C), peripheral (P), or normal (N). Binary analysis of Hc and Lc versus C and P was performed.
Results :
60 eyes from 30 patients were evaluated. 48 eyes of 24 patients mean age 55.6 ± 3.1(SEM) qualified (2 eyes with VEP + HVF or FDT within 12 months with C/P grades). 6 pairs had VF graded N. 66.7% of eyes with dominantly C VF loss showed Lc abnormality and 62.5% of eyes with dominantly P loss showed Hc abnormality (P=0.0441; mean 0.2917; confidence interval 0.0081-0.5753).
Conclusions :
Paired glaucomatous eyes with inverse bilateral Lc and Hc latency functionality showed a significant tendency for peripheral visual field loss in the eye with Lc VEP latency dysfunction and for central visual field loss in the Hc dysfunctional eye. This suggests CNS-directed binocular conservation of magnocellular and parvocellular function in progressive glaucoma is associated with bilaterally complementary patterns of visual field loss.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.