Comparison of perimetric Glaucoma Staging Systems in Asians with primary glaucoma.

Background: To compare functional staging classifications in Vietnamese patients with primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (PACG).
Methods: A retrospective cross-section study was conducted at a national setting. Two hundred seven eyes of 207 patients were recruited. Patients were tested with standard automated perimetry. Field loss was generally classified in four stages (normal, early, moderate, and severe), using four classification strategies: (1) Hodapp-Parrish-Anderson (HPA), (2) enhanced Glaucoma Staging System (eGSS), (3) modified Glaucoma Staging System (mGSS) and (4) the Advanced Glaucoma Intervention Study (AGIS). AGIS as a standard method was used to judge the staging performance of the other three classifications in terms of agreement (Cohen Kappa-K) and association (Chi-Square Test-Cramer's V).
Results: The agreement between AGIS and mGSS (K = 0.687; p < 0.001) and HPA (K = 0.686; p < 0.001) was substantial while that between AGIS and eGSS was slight (K = 0.103; p < 0.001). The association between AGIS and mGSS (V = 0.748; p < 0.001) and HPA (V = 0.748; p < 0.001) was greater than eGSS (V = 0.594; p < 0.001).
Conclusions: MGSS and HPA showed stronger agreement and closer association with AGIS than eGSS. We recommend mGSS should be used in managing a glaucoma clinic because of its simplicity and convenience over HPA and AGIS.