Correlation between Functional Staging and DDLS in Primary Open Angle Glaucoma Patients in Vietnam

Abstract

Clinically, there are many systems of visual field imaging systems. The agreement between glaucoma function and appearance is still uncertain. This study was conducted to compare visual field staging classifications (as function staging) with Disc Damage Likelihood Scale (DDLS as appearance staging) in Primary Open Angle Glaucoma (POAG). A cross-section study was performed using 55 patients (90 eyes) examined and treated by the Vietnam National Institute of Ophthalmology from 9/2016 - 9/2017. The MD (Mean Deviation), PSD (Pattern Standard Deviation), and VFI (Visual Field Index) indexes were recorded and were used to classify glaucoma staging according to categories of eGSS (enhanced Glaucoma Severity Staging), mGSS (modified Glaucoma Severity Staging), HPA (Hodapp-Parrish-Aderson), AGIS (Advanced Glaucoma Intervention Study), and DDLS. Using SPSS 16.0 software, statistical significance was tested with proper tests of Chi-square test, Fisher exact test, Kappa (to assess the agreement-disagreement), and Spearman Rank (to assess the level of correlation). Mean VFI were -11.49 dB (MD), 5.85 dB (PSD), and 74.2 % (VFI). Compared to DDLS, all systems had slight agreement (K < 0.2). The disagreement percentage was highest in eGSS (70 %), followed by mGSS (50 %) and HPA (48.9 %). In terms of definitive diagnosis, HPA and mGSS showed a substantial agreement (K > 0.6) with AGIS, which was higher than that between eGSS and AGIS (0.773 and 0.75 vs 0.399), with p < 0.001. In terms of staging detection, the agreement between HPA, mGSS, and AGIS was substantial (K > 0.6), while that between eGSS and AGIS was fair (K < 0.4). In conclusion, mGSS and HPA tended to show stronger agreement with standard classifications than eGSS. mGSS should be used in clinical practice and research.