Purpose:
To investigate the effect of myopia on Peripapillary Nerve Fiber Layer (RNFL) and Ganglion Cell Complex (GCC) values as measured by ONH and GCC scans of FD-OCT RTVue 100 in early glaucomatous eyes.
Methods:
88 eyes (88 patients) with Early Glaucoma (according to Hodapp classification) and 52 Normal eyes (52 subjects,age and sex matched) were included in the study. According to spherical equivalent (SE), each group has been subdivided into Non Myopic and Myopic subgroups (mean SE: -3.50 D in both groups, range: -2 to -9D). The more myopic eye was chosen as study eye. RNFL and GCC scans were obtained using RTVue 100. Correlation coefficients were calculated for demographic characteristics, macular and RNFL parameters, degree of myopia. The potential effect of age on the results was avoided applying a linear correction factor. Significance was set at p<0.05.
Results:
In Normal Group, the linear regression analysis shows a statistically significant thinning for both RNFL and GCC parameters as SE decreases, especially for GCCAvg (R:-0.39;p=0.004), GCCsup (R:-043;p=0.001) and GLV (R: 0.36;p=0.007). The comparison of correlations levels (non myopic vs myopic eyes) was significantly different for most of the parameters. In Early Glaucoma group the linear regression analysis shows significant correlations between macular and RNFL values with SE only for RNFLsup(R-0.27;p=0.01). The comparison of correlations levels (non myopic vs myopic eyes) was significantly different only for RNFLsup (p=0.02). No significant correlation was found with age nor in Normal neither in Early Glaucoma group.
Conclusions:
GCC and RNFL parameters in glaucomatous eyes vary with SE and age, but without statistical significance. Therefore Macular and Peripapillary measurements using FD-OCT RTVue 100 are useful parameters to assess and monitor glaucomatous damage in myopic eyes.
Keywords: ganglion cells • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic nerve