Physician survey for study of suppressive antiviral treatment to reduce chronic ocular disease and postherpetic neuralgia after herpes zoster ophthalmicus.

OBJECTIVES: The purpose of this study was to develop a consensus regarding the appropriate regimen to evaluate long-term suppressive antiviral treatment to reduce complications from herpes zoster ophthalmicus (HZO) and identify potential study sites. METHODS: In January 2013, a survey of 13 questions was distributed among cornea fellowship directors, board members of the Cornea Society and Ocular Microbiology and Immunology Group, and Kera-net Listserv members. Questions identified respondents' preferred antiviral regimens to administer for chronic or recurrent HZO, gauged the level of interest in participation in a planned randomized clinical trial, and assessed the number of HZO patients treated among specialists in the past year. RESULTS: Of the 171 respondents who completed the questionnaire, the majority identified as Kera-net Listserv members (107 of 171, 63%) and cornea fellowship directors (46 of 171, 27%). First choice of treatment was valacyclovir 500 mg 2 times per day (61 of 171, 36%), followed by acyclovir 800 mg 2 times per day (56 of 171, 33%), and then valacyclovir 1,000 mg daily (26.9%, 46 of 171). Among the choices, famciclovir consistently placed last among all the respondents (7 of 171, 4%). A majority (106 of 171, 62%) of all respondents, including 70% (26 of 37) of U. S. respondents of the high-volume practices, were interested in participating in a future randomized clinical trial evaluating whether treatment with oral antiviral medications for 1 year decreases complications of HZO. CONCLUSIONS: This survey highlights the strong interest in and support for further study of suppressive antiviral treatment regimens to reduce complications of HZO.

Longitudinal study of vision and retinal nerve fiber layer thickness in multiple sclerosis.

OBJECTIVE: Cross-sectional studies of optical coherence tomography (OCT) show that retinal nerve fiber layer (RNFL) thickness is reduced in multiple sclerosis (MS) and correlates with visual function. We determined how longitudinal changes in RNFL thickness relate to visual loss. We also examined patterns of RNFL thinning over time in MS eyes with and without a prior history of acute optic neuritis (ON). METHODS: Patients underwent OCT measurement of RNFL thickness at baseline and at 6-month intervals during a mean follow-up of 18 months at 3 centers. Low-contrast letter acuity (2.5%, 1.25% contrast) and visual acuity (VA) were assessed. RESULTS: Among 299 patients (593 eyes) with >or=6 months follow-up, eyes with visual loss showed greater RNFL thinning compared to eyes with stable vision (low-contrast acuity, 2.5%: p < 0.001; VA: p = 0.005). RNFL thinning increased over time, with average losses of 2.9microm at 2 to 3 years and 6.1microm at 3 to 4.5 years (p < 0.001 vs 0.5-1-year follow-up interval). These patterns were observed for eyes with or without prior history of ON. Proportions of eyes with RNFL loss greater than test-retest variability (>or=6.6microm) increased from 11% at 0 to 1 year to 44% at 3 to 4.5 years (p < 0.001). INTERPRETATION: Progressive RNFL thinning occurs as a function of time in some patients with MS, even in the absence of ON, and is associated with clinically significant visual loss. These findings are consistent with subclinical axonal loss in the anterior visual pathway in MS, and support the use of OCT and low-contrast acuity as methods to evaluate the effectiveness of putative neuroprotection protocols.

Retinal ganglion cell layer volumetric assessment by spectral-domain optical coherence tomography in multiple sclerosis: application of a high-precision manual estimation technique.

BACKGROUND: Neuronal loss in the retina has been demonstrated pathologically in eyes of patients with multiple sclerosis (MS). In vivo, MS eyes have reduced total macular volumes by optical coherence tomography (OCT). Using a high-resolution spectral-domain OCT, this pilot study used a manual method to measure ganglion cell layer (GCL) volumes and to determine the relation of these volumes to visual function in MS eyes. METHODS: Sixteen eyes of 8 patients with MS and 8 eyes of 5 disease-free control participants were studied using fast macular OCT scans performed with Spectralis OCT (Heidelberg Engineering). Visual function tests of low-contrast letter acuity and high-contrast visual acuity were administered. RESULTS: MS patient eyes had significantly lower GCL volumes than the control eyes (P < 0.001 vs controls, generalized estimating equation regression models accounting for age and within-patient intereye correlations). Within the MS group, eyes with a history of optic neuritis (ON, n = 4) had significantly lower GCL volumes than MS eyes with no ON history (P < 0.001). In contrast to measures of high-contrast visual acuity (P = 0.14), decreased GCL volumes were associated with worse performance on low-contrast letter acuity testing (P = 0.003). CONCLUSIONS: This pilot study has characterized thinning of the GCL in MS patient eyes, particularly in those with a history of acute ON, which corresponded to a reduced performance on low-contrast letter acuity testing. Studies utilizing computerized segmentation algorithms will continue to facilitate the detection of GCL loss on a larger scale and provide important information in vivo on the role and timing of neuronal vs axonal loss in MS eyes.

One eye or two: a comparison of binocular and monocular low-contrast acuity testing in multiple sclerosis.

PURPOSE: To determine the magnitudes of binocular summation for low- and high-contrast letter acuity in a multiple sclerosis (MS) cohort, and to characterize the roles that MS disease, age, interocular difference in acuity, and a history of optic neuritis have on binocular summation. The relation between binocular summation and monocular acuities and vision-specific quality of life (QoL) was also examined. DESIGN: Cross-sectional observational study. METHODS: Low-contrast acuity (2.5% and 1.25% contrast) and high-contrast visual acuity (VA) were assessed binocularly and monocularly in patients and disease-free controls at 3 academic centers. Binocular summation was calculated as the difference between the binocular and better eye scores. QoL was measured using the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and the 10-item neuro-ophthalmic supplement. The relation of the degree of binocular summation to monocular acuity, clinical history of acute optic neuritis, age, interocular acuity difference, and QoL was determined. RESULTS: Binocular summation was demonstrated at all contrast levels, and was greatest at the lowest level (1.25%). Increasing age (P < .0001), greater interocular differences in acuity (P < .0001), and prior history of optic neuritis (P = .015) were associated with lower magnitudes of binocular summation; binocular inhibition was seen in some of these patients. Higher magnitudes of summation for 2.5% low-contrast acuity were associated with better scores for the NEI VFQ-25 (P = .02) and neuro-ophthalmic supplement (P = .03). CONCLUSION: Binocular summation of acuity occurs in MS but is reduced by optic neuritis, which may lead to binocular inhibition. Binocular summation and inhibition are important factors in the QoL and visual experience of MS patients, and may explain why some prefer to patch or close 1 eye in the absence of diplopia or ocular misalignment.