Interpretation of RNFLT values in multiple sclerosis-associated acute optic neuritis using high-resolution SD-OCT device.
ABSTRACT Purpose: Optical coherence tomography (OCT) has emerged as the technique of choice in measuring the retinal nerve fibre layer (RNFL) quantitatively. It is suggested that RNFL reduction may correlate with lesion burden and diffuse axonal degeneration in the whole CNS of patients with multiple sclerosis (MS). However, RNFL changes because of optic neuritis (ON) must be taken into account. Methods: Twenty-three patients with acute ON (46 eyes) associated with clinical definite MS (23 ON eyes, 23 fellow eyes) and 23 sex- and age-matched healthy controls were studied. Retinal nerve fibre layer thickness (RNFLT) was measured at baseline, using a high-resolution spectral domain OCT (SD-OCT) applying circular, peripapillary OCT scans with a novel eye-tracking mechanism. Results: The internal OCT software was able to identify RNFL atrophy in three out of five of the acute ON eyes and one out of four of the fellow eyes with previous ON episodes. Retinal nerve fibre layer thickness of two ON (8.7%) and five fellow eyes (21.7%) was overestimated, thus located within the 95% and 5% confidence interval of the company standard values (not marked pathologic). In contrast, our comparison with age- and sex-matched controls revealed RNFL atrophy suggestive of prior, clinically silent RNFL loss in ON and fellow eyes (30.4%). Conclusion: Retinal nerve fibre layer thickness measurements at a single time-point seem to have a limited role in detecting prior clinically silent optic nerve injury. Our data suggest that affected eyes should be compared with the fellow eyes and a sufficient number of age- and sex-matched controls to allow the detection of even subtle RNFL changes at baseline. The role of OCT for disease monitoring of MS must be evaluated in detail, as ON is often the initial symptom of MS.
- SourceAvailable from: Ruben Cuadrado[show abstract] [hide abstract]
ABSTRACT: To assess the reproducibility of retinal nerve fiber layer (RNFL) measurements and the variability of the probabilistic classification algorithm in normal, hypertensive and glaucomatous eyes using Stratus optical coherence tomography (OCT). Forty-nine eyes (13 normal, 17 ocular hypertensive [OHT] and 19 glaucomatous) of 49 subjects were included in this study. RNFL was determined with Stratus OCT using the standard protocol RNFL thickness 3.4. Three different images of each eye were taken consecutively during the same session. To evaluate OCT reproducibility, coefficient of variation (COV) and intraclass correlation coefficient (ICC) were calculated for average thickness (AvgT), superior average thickness (Savg), and inferior average thickness (Iavg) parameters. The variability of the results of the probabilistic classification algorithm, based on the OCT normative database, was also analyzed. The percentage of eyes with changes in the category assigned was calculated for each group. The 50th percentile of COV was 2.96%, 4.00%, and 4.31% for AvgT, Savg, and Iavg, respectively. Glaucoma group presented the largest COV for all three parameters (3.87%, 5.55%, 7.82%). ICC were greater than 0.75 for almost all measures (except from the inferior thickness parameter in the normal group; ICC = 0.64, 95% CI 0.334-0.857). Regarding the probabilistic classification algorithm for the three parameters (AvgT, Savg, Iavg), the percentage of eyes without color-code category changes among the three images was as follows: normal group, 100%, 84.6% and 92%; OHT group, 89.5%, 52.7%, 79%; and Glaucoma group, 82%, 70.6%, and 76.5%, respectively. A probabilistic category switch from pathologic to normal or vice versa was observed in three eyes (15.8%) of the glaucomatous group for the Savg parameter and in two eyes of the OHT group: one eye (5,9%) for the AvgT and one eye (5.9%) for the Savg parameter. OCT RNFL measurements showed a good reproducibility in normal, OHT, and glaucoma eyes. The probabilistic classification for the three main parameters showed certain variability, especially in glaucoma group and OHT group. Therefore, one isolated category result should be interpreted with caution before clinical classification of the patient.Clinical ophthalmology (Auckland, N.Z.) 02/2009; 3:139-45.
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ABSTRACT: To test the reproducibility of retinal thickness measurements in healthy volunteers of a new Frequency-domain optical coherence tomography (OCT) device (Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany). Prospective, observational study. Forty-one eyes of 41 healthy subjects were included into the study. Intraobserver reproducibility was tested with 20 x 15 degree raster scans consisting of 37 high-resolution line scans that were repeated three times by one examiner (M.N.M.). Mean retinal thickness was calculated for nine areas corresponding to the Early Treatment Diabetic Retinopathy Study (ETDRS) areas. Coefficients of variation (COV) were calculated. Retinal thickness measurements were highly reproducible for all ETDRS areas. Mean total retinal thickness was 342 +/- 15 microm. Mean foveal thickness was 286 +/- 17 microm. COVs ranged from 0.38% to 0.86%. Lowest COV was found for the temporal outer ETDRS area (area 7; COV, 0.38%). Highest COV was found for the temporal inner ETDRS area (area 3; COV, 0.86%). Mean difference between measurement 1 and 2, measurement 1 and 3, and measurement 2 and 3 for all ETDRS areas was 1.01 microm, 0.98 microm, and 0.99 microm, respectively. Spectralis OCT retinal thickness measurements in healthy volunteers showed excellent intraobserver reproducibility with virtually identical results between retinal thickness measurements performed by one operator.American journal of ophthalmology 12/2008; 147(3):467-72. · 3.83 Impact Factor
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ABSTRACT: Optical coherence tomography (OCT) is an emerging clinical and research measure of retinal nerve fiber layer (RNFL) loss in multiple sclerosis (MS) and may reflect neurodegeneration. Few studies capture the effect of disease duration on the RNFL in subjects without exposure to disease-modulating therapies.We assessed the relationship of RNFL loss with disease duration in subjects with untreated MS and determined if such loss paralleled corticospinal tract dysfunction in MS.Subjects underwent OCT (n = 52) and visual testing (n = 60). Either they were either examined or they participated in a validated telephone interview so we could determine their Expanded Disability Status Scale (EDSS) scores.Both RNFL thickness (Spearman r(s) = -0.47, p < 0.001) and EDSS scores ( r(s) = 0.51, p < 0.001) correlated with disease duration. RNFL thickness correlated with EDSS scores (r(s) = -0.43, p < 0.001).In conclusion, RNFL loss correlates with disease duration and EDSS scores in subjects with untreated MS, indicating that OCT may capture neurodegeneration.The Journal of Rehabilitation Research and Development 01/2009; 46(5):633-42. · 1.78 Impact Factor