Purpose To characterize the rate of macula vessel density loss in primary open angle glaucoma (POAG), glaucoma suspect, and healthy eyes. Design Longitudinal, observational cohort from the Diagnostic Innovations in Glaucoma Study. Methods One hundred eyes (32 POAG, 30 glaucoma suspect and 38 healthy) followed for at least one year with optical coherence tomography angiography (OCT-A) imaging on at least two visits were included. Vessel density was calculated in the macula superficial layer. The rate of change was compared across diagnostic groups using multivariate linear mixed-effects model. Results Baseline macula vessel density was highest in healthy eyes, followed by glaucoma-suspect and POAG eyes (P < 0.01). The rate of vessel density loss was significantly different from zero in the POAG, but not in the glaucoma suspect or healthy eyes. The mean rate of change in macula whole en-face vessel density was significantly faster in glaucoma eyes (−2.23 %/yr) than in glaucoma suspect (0.87%/yr, P = 0.001) or healthy eyes (0.29 %/yr, P = 0.004). Conversely, the rate of change in ganglion cell complex (GCC) thickness was not significantly different from zero in any diagnostic group, and no significant differences in the rate of GCC change among diagnostic groups were found. Conclusions With a mean follow-up of less than 14 months, eyes with POAG had significantly faster loss of macula vessel density than either glaucoma suspect or healthy eyes. Serial OCT-A measurements also detected glaucomatous change in macula vessel density in eyes without evidence of change in GCC thickness.

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High density plasma production using m= +I and m=-1 helicon waves is studied. Characteristics of cylindrical helicon waves including effects of a vacuum gap between the plasma and the conducting wall and of a non-uniform separately excited by a helical antenna, and the dependences of plasma density and antenna loading resistance on RF power are shown to be different for these modes.

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