Validation and test characteristics of a 10-item neuro-ophthalmic supplement to the NEI-VFQ-25.

PURPOSE: To determine whether a 10-Item Neuro-Ophthalmic Supplement increases the capacity of the 25-Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) to capture self-reported visual dysfunction in patients with neuro-ophthalmologic disorders. DESIGN: A cross-sectional survey to examine the characteristics of a 10-Item Neuro-Ophthalmic Supplement to the 25-Item NEI-VFQ-25 in a cohort of patients with neuro-ophthalmologic disorders. METHODS: The 10-Item Neuro-Ophthalmic Supplement was designed previously by our research group by survey and focus-group methods. In the present study, the NEI-VFQ-25 and 10-Item Supplement were administered concurrently to patients and disease-free control subjects. High-contrast visual acuities with patient usual distance correction were measured with the use of Early Treatment Diabetic Retinopathy Study (ETDRS) charts. RESULTS: Diagnoses for patients (n = 215) included optic neuritis, multiple sclerosis, idiopathic intracranial hypertension, ischemic optic neuropathy, stroke, ocular myasthenia gravis, ocular motor palsies, and thyroid eye disease. Scores for the 10-Item Supplement had a significant capacity to distinguish patients vs disease-free control subjects that was independent of the NEI-VFQ-25 composite score (odds ratio in favor of patient vs control status for 10-point worsening in Supplement scores: 2.7 [95% confidence interval [CI], 1.6, 4.6]; P < .001, logistic regression models that account for NEI-VFQ-25 composite score, age, and gender). Patients with visual dysfunction (binocular Snellen equivalents worse than 20/20) had significantly lower mean scores (9-21 points lower); these differences remained significant after accounting for age and gender (P >or= .001, linear regression). Supplement items and composite scores demonstrated appropriate degrees of internal consistency reliability. CONCLUSION: The 10-Item Neuro-Ophthalmic Supplement demonstrates a capacity to capture self-reported visual dysfunction beyond that of the NEI-VFQ-25 alone, which supports validity for this new scale. The use of the 10-Item Supplement in clinical trials and epidemiologic studies will examine its capacity to demonstrate treatment effects in longitudinal cohorts.

Relation of visual function to retinal nerve fiber layer thickness in multiple sclerosis.

PURPOSE: To examine the relation of visual function to retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in multiple sclerosis (MS), and to compare RNFL thickness among MS eyes with a history of acute optic neuritis (MS ON eyes), MS eyes without an optic neuritis history (MS non-ON eyes), and disease-free control eyes. DESIGN: Cross-sectional study. PARTICIPANTS: Patients with MS (n = 90; 180 eyes) and disease-free controls (n = 36; 72 eyes). METHODS: Retinal never fiber layer thickness was measured using optical coherence tomography (OCT; fast RNFL thickness software protocol). Vision testing was performed for each eye and binocularly before OCT scanning using measures previously shown to capture dysfunction in MS patients: (1) low-contrast letter acuity (Sloan charts, 2.5% and 1.25% contrast levels at 2 m) and (2) contrast sensitivity (Pelli-Robson chart at 1 m). Visual acuity (retroilluminated Early Treatment Diabetic Retinopathy charts at 3.2 m) was also measured, and protocol refractions were performed. MAIN OUTCOME MEASURES: Retinal nerve fiber layer thickness measured by OCT, and visual function test results. RESULTS: Although median Snellen acuity equivalents were better than 20/20 in both groups, RNFL thickness was reduced significantly among eyes of MS patients (92 mum) versus controls (105 mum) (P<0.001) and particularly was reduced in MS ON eyes (85 mum; P<0.001; accounting for age and adjusting for within-patient intereye correlations). Lower visual function scores were associated with reduced average overall RNFL thickness in MS eyes; for every 1-line decrease in low-contrast letter acuity or contrast sensitivity score, the mean RNFL thickness decreased by 4 mum. CONCLUSIONS: Scores for low-contrast letter acuity and contrast sensitivity correlate well with RNFL thickness as a structural biomarker, supporting validity for these visual function tests as secondary clinical outcome measures for MS trials. These results also suggest a role for ocular imaging techniques such as OCT in trials that examine neuroprotective and other disease-modifying therapies. Although eyes with a history of acute optic neuritis demonstrate the greatest reductions in RNFL thickness, MS non-ON eyes have less RNFL thickness than controls, suggesting the occurrence of chronic axonal loss separate from acute attacks in MS patients.