Abstract
Purpose:
To evaluate association between the magnitude of relative afferent pupillary defect (RAPD) with pupillography and macular ganglion cell complex thickness (MGCCT) in asymmetric glaucoma.
Methods:
We used RAPDx (Konan Medical USA, USA) to evaluate RAPD. The RAPDx is designed to analyze pupil response at multiple, controlled stimulus intensities and multiple color stimuli (white, red, green, blue and yellow). This device records precise amplitude and latency of pupil responses. Inclusion criteria were having optic disc abnormalities and visual field loss with glaucoma. Patients with having retinal disease, optic neuropathy, cornea disease, non-reactive pupils and asymmetric cataract were excluded. MGCCT was measured with spectral domain optical coherence tomography (RS-3000; Nidek, Japan). We evaluated association between asymmetry of the macular MGCCT and RAPDx amplitude and latency of multiple color stimuli (white, red, green, blue and yellow).
Results:
Fifty six glaucoma patients (34 males, 22 females; mean age: 62.6 ± 12.0 years; range: 28 - 88 years) were enrolled. Mean MGCCT were 88.9 ± 12.2 (range: 56 - 112) μm in thicker eyes and 76.3 ± 12.5 (range: 53 - 103) μm in thinner eyes. The differences of MGCCT (thicker eye - thinner eye) were 12.7 ± 10.8 (range: 1 - 40) μm. The log-scaled RAPD amplitude were as follows; white 0.37±0.47, red 0.26±0.78, green 0.33±0.54, blue 0.40±0.62, yellow 0.35±0.56. The results of linear regression analysis between the log-scaled RAPD amplitude and the MGCCT asymmetry were as follows; white R2 = 0.44 (p<0.001), red R2 = 0.29 (p<0.001), green R2 = 0.27 (p<0.001), blue R2 = 0.24 (p<0.001), yellow R2 = 0.25 (p<0.001). The log-scaled RAPD latency were as follows; white 0.09±0.23, red -0.01±0.38, green 0.12±0.39, blue 0.07±0.54, yellow -0.04±0.21. The results of linear regression analysis between the log-scaled RAPD latency and the MGCCT asymmetry were as follows; white R2 = 0.07 (p = 0.04), red R2 = 0.001 (p = 0.76), green R2 = 0.04 (p = 0.15), blue R2 = 0.05 (p = 0.08), yellow R2 = 0.02 (p = 0.25).
Conclusions:
Log-scaled RAPD amplitude had moderate correlation to MGCCT asymmetry, however RAPD latency had weaker relationship to MGCCT asymmetry. White stimulus had stronger relationship to MGCCT asymmetry than other colored stimuli.
Keywords: 668 pupillary reflex •
531 ganglion cells •
629 optic nerve