Evaluation of peripapillary retinal nerve fiber layer thickness in patients with primary open-angle glaucoma

Abstract

Introduction/Objective. Determination of the difference in peripapillary retinal nerve fiber layer (RNFL) thickness in patients with open-angle glaucoma (POAG) in comparison to the healthy population and according to the progression of the disease. Methods. Four groups were formed among 120 patients: group without glaucoma, early, moderate POAG and preperimetric glaucoma group. Visual field and optical coherent tomography were performed. Results. RNFL thickness value was found to be the highest in inferior quadrant, second highest in superior, third in nasal, the lowest in temporal quadrant. The highest average value of RNFL thickness was in superior quadrant of the healthy group (124.3 ? 17.8?m), and the lowest was in temporal quadrant of the moderate group (46.5 ? 10.8?m). Other RNFL thickness values per quadrants among groups were distributed between these two endpoints. AvgThic in patients with moderate POAG was lesser than in patients with early POAG, which was lesser than in the healthy subjects (59.6 ? 10.6?m vs. 73.4 ? 12.1?m vs. 105.5 ? 11.3?m). AvgThic in preperimetric glaucoma group was 83.6 ? 9.2?m. Pearson correlation showed high positive correlation between MD values and following parameters: AvgThic, S, I, Smax, Imax, Savg, Iavg. ROC curves found that the parameter with the best diagnostic ability was AvgThic, with area of 0.803(< 0.0005), sensitivity of 67% and specificity of 83.3%. Conclusion. Peripapillary RNFL thickness parameters: AvgThic, S, I, Smax, Savg, Iavg, Imax have excellent ability to discriminate between healthy eyes and eyes with POAG. The parameter with the highest specificity and sensitivity is AvgThic, which makes it the best for early detection and monitoring of POAG.