Use of suprathreshold test data to predict the results of quantitative testing in the nasal periphery

We compared the results of suprathreshold testing of the nasal periphery with those of quantitative assessment of the same area. One eye each from 81 patients in four categories (normal [21 subjects], low-risk ocular hypertensive [20 subjects], high-risk ocular hypertensive [20 subjects] and early glaucoma [20 subjects]) was tested with the nasal suprathreshold points of the Octopus G1 program and the Sargon peripheral field-nasal (PFN) program. Simple algorithms were developed to generate from the nasal suprathreshold points of the G1 program two "qualitative indices", mean defect-qualitative (MD-Q) and loss variance-qualitative (LV-Q); these are analogous to the indices mean defect and loss variance respectively, which were calculated from the PFN program data. MD-Q and LV-Q were found to be well correlated with their quantitative counterparts. They provide a uniform method for interpreting the nasal suprathreshold points of the G1 program and help identify patients in whom further quantitative testing is likely to yield useful information.