Dataset Information

The Photopic Negative Response in Idiopathic Intracranial Hypertension.

ABSTRACT:

Purpose

To evaluate the photopic negative response (PhNR) as an index of retinal ganglion cell (RGC) function in idiopathic intracranial hypertension (IIH).

Methods

Amplitude and implicit time of the PhNR, as elicited by full-field, brief-luminance flashes, was measured in IIH (n = 10) and visually normal control (n = 15) subjects. Visual function was assessed in IIH subjects using standard automated perimetry mean deviation (SAP-MD) scores. Optic nerve structure was evaluated using the Frisén papilledema grading scale (FPG). Macula ganglion cell complex volume (GCCV) was extracted from optical coherence tomography images to assess RGC loss.

Results

Median PhNR amplitude was significantly lower in IIH subjects compared with control subjects (P = 0.015, Mann-Whitney Rank Sum [MW]), but implicit time was similar (P = 0.54, MW). In IIH subjects, PhNR amplitude and SAP-MD were correlated (Pearson's r = 0.78, P = 0.008). Ganglion cell complex volume was correlated with both SAP-MD (r = 0.72, P = 0.019) and PhNR amplitude (r = 0.77, P = 0.009). Multivariate linear regression models demonstrated that the correlation between GCCV and PhNR amplitude was improved by accounting for FPG in the model (r = 0.94, P < 0.0001), but the correlation between GCCV and SAP-MD was not (r = 0.74, P = 0.009).

Conclusions

Photopic negative response amplitude, which can be decreased in IIH subjects, correlates well with a clinical measure of visual function (SAP-MD). In multivariate models, it correlated with both an imaging measure of chronic ganglion cell injury (GCCV) and a clinical measure of acute optic nerve head pathology (FPG). Further studies are needed to determine the clinical utility of PhNR as a marker for diagnosis and monitoring of IIH.

SUBMITTER: Moss HE

PROVIDER: S-EPMC4466812 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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Publications

The Photopic Negative Response in Idiopathic Intracranial Hypertension.

Moss Heather E HE Park Jason C JC McAnany J Jason JJ

Investigative ophthalmology & visual science 20150601 6

<h4>Purpose</h4>To evaluate the photopic negative response (PhNR) as an index of retinal ganglion cell (RGC) function in idiopathic intracranial hypertension (IIH).<h4>Methods</h4>Amplitude and implicit time of the PhNR, as elicited by full-field, brief-luminance flashes, was measured in IIH (n = 10) and visually normal control (n = 15) subjects. Visual function was assessed in IIH subjects using standard automated perimetry mean deviation (SAP-MD) scores. Optic nerve structure was evaluated usi ...[more]

PMID: 26047172

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Project description:ObjectiveTo characterize the phenotype, headache-related disability, medical co-morbidities, use of symptomatic headache medications, and headache response to study interventions in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT).MethodsPatients with untreated IIH and mild vision loss enrolled in the IIHTT and randomized to acetazolamide (ACZ) and weight loss or placebo (PLB) and weight loss had prospective assessment of headache disability using the Headache Impact Test-6 (HIT-6) questionnaire. Subjects with headache at the baseline visit were assigned a headache phenotype using the International Classification for Headache Disorders version 3 beta (ICHD-3b). Medication overuse was determined using the participants' reported medication use for the preceding month and ICHD-3b thresholds for diagnosing medication overuse headache. We investigated relationships between headache disability and various other clinical characteristics at baseline and at 6 months.ResultsHeadache was present in 139 (84%) of the 165 enrollees at baseline. The most common headache phenotypes were migraine (52%), tension-type headache (22%), probable migraine (16%), and probable tension-type headache (4%). Fifty-one (37%) participants overused symptomatic medications at baseline, most frequently simple analgesics. A similar amount of improvement in the adjusted mean (± standard error) HIT-6 score occurred in the ACZ (-9.56 ± 1.05) and PLB groups (-9.11 ± 1.14) at 6 months (group difference -0.45, 95% CI -3.50 to 2.60, P = .77). Headache disability did not correlate with any of the studies, variables of interest, which included: the lumbar puncture opening pressure at baseline or at 6 months, body mass index, the amount of weight lost, papilledema grade, perimetric mean deviation, or the use of hormonal contraception. Headache disability was significantly associated with patient-reported quality of life in the physical, mental, and visual domains.ConclusionsHeadache was common, of varied character, disabling, and associated with poorer quality of life in our cohort of patients with mild visual impairment. The lack of correlation between headache disability and cerebrospinal fluid (CSF) pressure at baseline and at the end of the randomized phase of the study implies that headache in IIH may be related to factors other than intracranial hypertension, and that specific headache treatment is needed in addition to therapies directed at lowering CSF pressure.

Dataset Information

The Photopic Negative Response in Idiopathic Intracranial Hypertension.

Purpose

Methods

Results

Conclusions

Publications

The Photopic Negative Response in Idiopathic Intracranial Hypertension.

Similar Datasets

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