Relationship Between Retinal Nerve Fiber Layer Thickness and Retinal Sensitivity Assessed by Humphrey Matrix and Scanning Laser Polarimetry

Abstract

Purpose: : To evaluate the relationship between retinal sensitivity and retinal nerve fiber layer (RNFL) thickness assessed by Humphrey Matrix (Matrix) and Scanning laser polarimetry with variable corneal compensation (GDx-VCC)

Methods: : 70 glaucomatous eyes based on optic disc examination and standard automated perimetry (SAP) were classified into 2 groups, early (mean deviation (MD)>-6) and moderate to advanced group (MD<-6) by SAP. The relationships between mean retinal sensitivity (MS) by the Matrix and RNFL thickness were compared globally and regionally with linear and logarithmic regression analysis.

Results: : In both groups, inferior average thickness was lower than superior average thickness. The global MS was significantly correlated with TSNIT average thickness (R²=0.21;linear, R²=0.22;logarithmic). The superior MS was correlated with inferior average thickness (R²=0.41;linear, R²=0.40;logarithmic) and inferior MS with superior average thickness (R²=0.27;linear, R²=0.29;logarithmic) in the early group.The superior MS was correlated with inferior average thickness (R²=0.17;linear, R²=0.19;logarithmic) and inferior MS with superior average thickness (R²=0.36;linear, R²=0.36;logarithmic) in the moderate to advanced group.

Conclusions: : The RNFL thickness measured by GDxVCC was well correlated with corresponding retinal sensitivity determined by the Matrix. In the early group, the structure-function relationship was stronger in the hemifield (superior field) that corresponded with more damaged RNFL region (inferior sector).However, in the moderate to advanced group, it was stronger in the hemifield (inferior field) that corresponded with less damaged RNFL region (superior sector).

Keywords: imaging/image analysis: clinical • visual fields