## 4 Discussion  
In the current study, we found significant inter-eye differences in the cup area, cup/disc area ratio, linear CDR, horizontal CDR, and vertical CDR in anisometropic myopic subjects using HRT. Moreover, significant correlations were found between inter-eye differences in ONH parameters and inter-eye differences in AL/SE in terms of cup/disc area ratio, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Cup/Disc Area Ratio**} & \multicolumn{2}{c}{**Vertical CDR**} & \multicolumn{2}{c}{**Horizontal CDR**} \\ \cline{2-6}  & \(\beta\) & \(P\) & \(\beta\) & \(P\) & \(\beta\) & \(P\) \\ \hline SE & 0.184 & 0.508 & 0.342 & 0.230 & 0.189 & 0.557 \\ AL & 0.126 & 0.450 & 0.281 & 0.330 & 0.083 & 0.799 \\ Disc area & 0.561 & 0.001 & 0.499 & 0.003 & 0.318 & 0.076 \\ \hline \hline \end{tabular}  
* AL: axial length; SE: spherical equivalent. CDR: cup/disc ratio.  
\end{table} 
Table 4: Factors associated with cup/disc area ratio, vertical CDR, and horizontal CDR (multiple linear regression analysis). \begin{table}
\begin{tabular}{c c c} \hline \hline \begin{tabular}{c} **Inter-Eye Difference in Parameters** \\ **(Value\({}_{\text{less}}\) myopic eye\({}_{\text{``Value\_{more}}\) myopic eye\({}^{\text{)}}}\)** \\ \end{tabular} & \begin{tabular}{c} **Correlation with Inter-Eye Difference in SE** \\ **(Value\({}_{\text{less}}\) myopic eye\({}^{\text{)}}\)** \\ \end{tabular} & \begin{tabular}{c} **Correlation with Inter-Eye Difference in SE** \\ **(Value\({}_{\text{less}}\) myopic eye\({}^{\text{)}}\)** \\ \end{tabular} & \begin{tabular}{c} **Correlation with Inter-Eye Difference in SE** \\ **(Value\({}_{\text{less}}\) myopic eye\({}^{\text{)}}\)** \\ \end{tabular} & \
\begin{tabular}{c} **Correlation with Inter-Eye Difference in SE** \\ **(Value\({}_{\text{less}}\) myopic eye\({}^{\text{)}}\)** \\ \end{tabular} &
\begin{tabular}{c} **(\(P\))** \\ **(P) (\(r=18)** \\ \end{tabular} \\ \hline Inter-eye difference in cup area & 0.61 (0.008) & 0.60 (0.009) \\ Inter-eye difference in cup/disc area ratio & 0.57 (0.014) & 0.61 (0.007) \\ Inter-eye difference in disc area & 0.48 (0.043) & 0.49 (0.041) \\ Inter-eye difference in horizontal CDR & 0.48 (0.043) & 0.56 (0.016) \\ Inter-eye difference in rim/disc area ratio & \(-0.57\ (0.014) & \(-0.61\ (0.007)\) \\ Inter-eye difference in vertical CDR & 0.60 (0.009) & 0.62 (0.006) \\ Inter-eye difference in linear CDR & 0.56 (0.017) & 0.62 (0.007) \\ Inter-eye difference in rim area & 0.02 (0.939) & 0.04 (0.887) \\ \hline \hline \end{tabular}  
* AL: axial length; SE: spherical equivalent. CDR: cup/disc ratio.  
\end{table} 
Table 3: Correlations between inter-eye differences in ONH parameters and SE/AL (Pearson correlation). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Inter-Eye Difference in**} & \multicolumn{2}{c}{**Inter-Eye Difference in**} & \multicolumn{2}{c}{**Inter-Eye Difference in**} \\  & **Cup/Disc Area Ratio** & \multicolumn{2}{c}{**Vertical CDR**} & \multicolumn{2}{c}{**Horizontal CDR**} \\ \cline{2-6}  & \(\beta\) & \(P\) & \(\beta\) & \(P\) & \(\beta\) & \(P\) \\ \hline SE & 0.184 & 0.508 & 0.342 & 0.230 & 0.189 & 0.557 \\ AL & 0.126 & 0.450 & 0.281 & 0.330 & 0.083 & 0.799 \\ Disc area & 0.561 & 0.001 & 0.499 & 0.003 & 0.318 & 0.076 \\ \hline \hline \end{tabular}  
* AL: axial length; SE: spherical equivalent. CDR: cup/disc ratio.  
\end{table} 
Table 4: Factors associated with cup/disc area ratio, vertical CDR, and horizontal CDR (multiple linear regression analysis). rim/disc area ratio, horizontal CDR, vertical CDR, and linear CDR. Inter-eye differences in cup and disc areas were also found to be significantly correlated with the inter-eye difference in AL. A larger disc area was independently and significantly associated with a larger cup/disc area ratio and vertical CDR. The inter-eye difference in vertical CDR was positively correlated with the inter-eye difference in AL using the inter-eye difference in disc area as a covariate in a regression model.