Relationship between retinal nerve fiber layer evaluation and visual field results in healthy and glaucoma individuals

Abstract

Purpose To determine the relationship between retinal nerve fiber layer (RNFL) thickness measured with spectral‐domain optical coherence tomography (OCT) and the retinal sensitivity tested by standard automated perimetry (SAP). Methods Two hundred and five subjects (100 healthy and 105 with different levels of glaucomatous damage subjects) were prospective and consecutively recruited. Only one eye per participant was randomly chosen. Glaucoma patients had intraocular pressure higher than 21 mmHg and glaucomatous optic disc appearance. All of them underwent imaging with the Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) and at least one reliable perimetry. SAPs were performed with a Humphrey Field Analyzer, using the 24‐2 SITA Standard strategy. Left eye data were converted to a right eye format. The Kolmogorov Smirnov test was applied to check that the data were normally distributed. Threshold values of SAP were converted to a linear scale. Pearson correlations were calculated between the 52 threshold values tested by 24‐2 algorithm of SAP and OCT parameters Results Age was not different between both groups (p=0.09). In the whole sample, the strongest correlation was found between point 15 of SAP and RNFL thickness at inferior quadrant (r=0.670; p<0.001). The healthy group showed few and mild correlations. In the glaucoma group, the strongest correlation was also found between point 15 of SAP and inferior RNFL thickness at inferior quadrant (0.664; p<0.001). Conclusion Normal individuals had mild correlations between few functional and structural parameters, while glaucoma patients showed mild to moderate correlations.