Evaluation of 2D FLAIR hyperintensity of the optic nerve and optic nerve head and visual parameters in idiopathic intracranial hypertension.

BACKGROUND AND PURPOSE: T2/FLAIR hyperintensity of the optic nerve/optic nerve head has been described as a sensitive finding in idiopathic intracranial hypertension using post-contrast 3D-T2/FLAIR imaging. The purpose of this study is to assess whether hyperintensity on non-enhanced 2D-T2/FLAIR imaging occurs more likely in diseased patients than controls and to evaluate the relationship between FLAIR signal and visual parameters MATERIALS AND METHODS: A retrospective case-control study was performed of patients with idiopathic intracranial hypertension and controls who underwent orbital MRI. Three neuroradiologists reviewed the FLAIR images, subjectively evaluating for hyperintense signal within the optic nerves/optic nerve heads using a 5-point Likert Scale. Quantitative assessment of optic nerve signal using regions of interests was performed. Clinical parameters were extracted. The diagnostic performance was evaluated, and Spearman correlation calculated to assess the relationship between FLAIR signal and visual outcomes. RESULTS: The sensitivity of abnormal FLAIR signal within the optic nerves and optic nerve heads in patients with idiopathic intracranial hypertension ranged from 25-54% and 4-29%, respectively, with specificities ranging from 67-92% and 83-100%. Quantitative assessment revealed a significant difference in CNR between cases and controls in the left posterior optic nerve (p=.002). A positive linear relationship existed between abnormal optic nerve head signal and papilledema grade (OD: p=.02, OS: p=.008) but not with other visual parameters. CONCLUSION: T2/FLAIR hyperintensity in the optic nerve/optic nerve head may support the diagnosis of idiopathic intracranial hypertension but its absence should not dissuade it. If present, abnormal signal in the optic nerve head correlates with papilledema.

Success of Masking 5% Povidone-Iodine Treatment: The Reducing Adenoviral Patient Infected Days Study.

SIGNIFICANCE: The effectiveness of masking is rarely evaluated or reported in single- or double-masked clinical trials. Knowledge of treatment assignment by participants and clinicians can bias the assessment of treatment efficacy. PURPOSE: This study aimed to evaluate the effectiveness of masking in a double-masked trial of 5% povidone-iodine for the treatment of adenoviral conjunctivitis. METHODS: The Reducing Adenoviral Patient Infected Days study is a double-masked, randomized trial comparing a one-time, in-office administration of 5% povidone-iodine with artificial tears for the treatment of adenoviral conjunctivitis. Masking was assessed by asking participants and masked clinicians at designated time points if they believed the treatment administered was povidone-iodine or artificial tears, or if they were unsure. Adequacy of masking was quantified using a modified Bang Blinding Index. RESULTS: Immediately after treatment, 34% of participants who received povidone-iodine and 69% of those who received artificial tears guessed incorrectly or were unsure of their treatment (modified Bang Indices of 0.31 and -0.38, respectively). On day 4, 38% of the povidone-iodine participants and 52% of the artificial tear participants guessed incorrectly or were unsure of their treatment (modified Bang Indices of 0.24 and -0.05, respectively), indicating adequate and ideal masking. On days 1, 4, 7, 14, and 21, masked clinicians guessed incorrectly or were unsure of treatment in 53%, 50%, 40%, 39%, and 42% among povidone-iodine participants compared with 44%, 35%, 38%, 35%, and 39% among artificial tears participants, respectively. The modified Bang Indices for clinician masking in the povidone-iodine group ranged from -0.05 to 0.25 and from 0.13 to 0.29 in the artificial tears group. CONCLUSIONS: Masking of participants and clinicians was adequate. Successful masking increases confidence that subjective measurements are not biased. We recommend quantitative assessment and reporting the effectiveness of masking in ophthalmic clinical trials.