Abstract
Purpose :
Previously we demonstrated the overall parameters of standard automated perimetry (SAP) adjusted to the multifocal ERG grid (mf103) in comparison to the Octopus G2 protocol. Here we present their focal relationship and correspondence to morphological changes (RNFL, GCIPL and macular thickness) assessed with OCT.
Methods :
18 primary open angle glaucoma patients (POAG) and 15 controls underwent OCT (Macular and Optic Disc Cubes, Cirrus SD-OCT, Carl Zeiss) and SAP (mf103 and G pattern, Octopus, Haag-Streit). Analysis: SAP: focal MS and MD, values in dB. OCT: macular thickness (mT), ganglion cell analysis (GCIPL) and retinal nerve fiber layer (RNFL) thickness as per Cirrus software. All values were clustered into 12 corresponding group-averages, taking into account the nerve fiber distribution and 2 group averages corresponding to the central 10° and 20°. SAP groups are presented in retinal view to directly correspond to OCT.
Results :
Mean RNFL was 69.06 μm (SD 11.4) for POAG and 90.27 μm (SD 10.7) for controls (p<0.01). Average mT and GCIPL were 283.6 μm (SD 14.3) and 67.9 μm (SD 8.9) for POAG respectively 293.7 μm (SD 12.4) and 80.9 μm (SD 4.8) for controls (p<0.05,all). POAG and controls had a mean MD of 3.47 dB (SD 4.0) and 0.13 dB (SD 1.7) for G2 (p= 0.006) while averages for mf103 were 3.95 dB (SD 3.8) and 0.59 dB (SD 1.5), respectively (p= 0.004). Mf103 clustered parameters (MD & MS) had a significant association with more RNFL clusters than G2. While both showed a significant correlation in the inferior clusters, mf103 also showed a positive association with superior RNFL thinning. GCIPL discriminated better between POAG and control (p<0.0001) than mT alone (p<0.029). mT was significantly associated with G2 (MD & MS) in the central 10° (p<0.01) but with mf103 in the central 20° p<0.05). Neither mf103 nor G2 was significantly associated with GCIPL thickness. This relates to only 38% of patients with focal field defects within the central 10°. Subgroup analysis demonstrated that these correlations are only significant in POAG.
Conclusions :
In POAG mf103 correlates better with RNFL thickness than G2. Both SAP do not correlate with GCIPL changes. Thus neither the G2 nor the mf103 pattern are optimal for correlation with initial defects shown in the inner GCIPL ellipse covering a radius of 7-8° visual angle.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.