Discussion
visual field loss, IIH, glaucoma
GLAUCOMA
In this study, we characterized the pointwise pattern of visual field change in a cohort of people with active IIH recruited to the IIH:WT. Those with baseline point sensitivities between 0 dB and −10 dB showed small changes over time and, as expected, were unlikely to demonstrate clinically meaningful change over both 12 and 24 months. Points in the −10 to −25 dB category demonstrated change that could be considered clinically meaningful (mean of 8.5 dB in at least one point in the whole visual field); however, using data between −10 dB and −25 dB resulted in fewer data points and larger SDs for analysis. Although the median number of points worse than −10 dB was five, 43% of all of the IIH:WT participants had fewer than two points worse than −10 dB at baseline, emphasizing that data points worse than −10 dB were not representative of the majority of IIH patients.It should be emphasized that eligibility for the IIH:WT was not determined by MD criteria. Therefore, to simulate the HVF data to reflect a typically medically managed cohort, we chose a baseline HVF in which the MD was between −2 dB and −7 dB (the criterion range used in the IIHTTThere is no universally adopted, minimally clinically important change in HVF measures in IIH as there are in glaucoma.A limitation of this study is that it included only patients with well-established IIH. Thus, the results may not be applicable to patients with recently diagnosed IIH or to severely affected patients who may require urgent surgery.In this study and in studies reported by others,Our data indicate that point analysis of the HVF has no advantage over global MD analysis, at least in the population we studied from the IIH:WT. As expected, baseline points that were better than −10 dB had little room to improve over time and, thus, offered little utility for analysis. If the generic threshold for a clinically meaningful change of 7 dB is recommended for IIH treatment trials, baseline points in the range of −10 to −25 dB would be needed for analysis. The US Food and Drug Administration has stated that visual field loss has likely occurred if ≥5 visual field locations have significant change beyond the 5% probability level or if there is at least a 7-dB between-group mean difference for the entire field.