Topcon 3D OCT-1000 Research Articles

Macular and Retinal Nerve Fiber Layer Thickness Measurements in Normal Eyes With the Stratus OCT, the Cirrus HD-OCT, and the Topcon 3D OCT-1000

To compare retinal nerve fiber layer (RNFL) and macular thickness measurements using time-domain optical coherence tomography (TD OCT) and 2 Fourier-domain OCTs (FD OCT). Sixty eyes of 60 normal participants underwent eye examination followed by OCT evaluation with the time-domain Stratus OCT (Carl Zeiss Meditec, Inc. Dublin, CA) and 2 FD OCTs-the Cirrus HD-OCT (Carl Zeiss Meditec, Inc. Dublin, CA) and the 3D OCT-1000 (Topcon Corporation, Tokyo, Japan). Each patient was scanned 3 times on each machine by the same physician examiner. RNFL and macular thickness measurements were compared across the 3 devices using repeated measures analysis of variance (ANOVA) and multiple comparison t tests with Bonferroni adjustments. The coefficients of variation (CV) and the intraclass correlation coefficients were calculated to assess reproducibility. Bland-Altman plots were constructed to assess the level of agreement between every 2 OCTs. All 3 machines revealed similar patterns of regional differences in RNFL and macular thicknesses. Macular thickness was consistently greatest on the Cirrus and lowest on the Stratus device. However, RNFL measurements were less consistent. The overall average RNFL thickness was 4 μm greater on the Stratus than on the 3D OCT-1000, which was in turn 5 μm greater than on the Cirrus device. Bland-Altman plots showed poor-to-moderate agreement in terms of macular and RNFL thickness measurements between each 2 of the OCT devices. Both FD OCTs provided more reproducible readings on macular measurements than the Stratus, as evidenced by the lower CV and higher intraclass correlation coefficients. However, RNFL measurements on the 2 FD OCTs were not necessarily more reproducible than those from the Stratus OCT. Thickness measurements are not interchangeable among different OCT devices because of the poor-to-moderate interdevice measurement agreement. FD instruments yield more reproducible macular but not RNFL thickness measurements.

Repeatability of Retinal Thickness Measurements Between Spectral-Domain and Time-Domain Optical Coherence Tomography Images in Macular Disease

To evaluate and compare the intra-session repeatability of retinal thickness measurements from the Topcon 3D OCT 1000 (Topcon Medical Systems; Paramus, NJ), a spectral-domain optical coherence tomography (SD-OCT) system, with the Stratus (Carl Zeiss Meditec, Inc., Dublin, CA), a time-domain OCT (TD-OCT) system, in eyes with retinal diseases. Repeated scans with both SD-OCT and TD-OCT were taken. Thickness measurements from high-quality scans were used to assess repeatability and compare measurements between the two instruments. Paired scans from 127 eyes were evaluated, of which 63 pairs were of high quality. Coefficients of repeatability and variation for the central subfield were 20.1 μm (2.6%) with SD-OCT and 27.4 μm (4%) with TD-OCT (P = .38). The mean difference in central subfield thickness between the two instruments was 24.5 μm (standard deviation = 20.9). Repeatability of retinal thickness measurements with the Topcon 3D OCT 1000 is comparable to the Stratus. The measurements of the two machines differ significantly and cannot be used interchangeably.

Assessment of Artifacts and Reproducibility across Spectral- and Time-Domain Optical Coherence Tomography Devices

To report the frequency of optical coherence tomography (OCT) scan artifacts and to compare macular thickness measurements, interscan reproducibility, and interdevice agreeability across 3 spectral-domain (SD) OCT (also known as Fourier domain; Cirrus HD-OCT, RTVue-100, and Topcon 3D-OCT 1000) devices and 1 time-domain (TD) OCT (Stratus OCT) device. Prospective, noncomparative, noninterventional case series. Fifty-two patients seen at the New England Eye Center, Tufts Medical Center Retina Service, between February and August 2008. Two scans were performed for each of the SD OCT protocols: Cirrus macular cube 512 x 128 (software version 3.0; Carl Zeiss Meditec, Inc., Dublin, CA), RTVue (E)MM5 and MM6 (software version 3.5; Optovue, Inc., Fremont, CA), Topcon 3D Macular and Radial (software version 2.12; Topcon, Inc., Paramus, NJ), in addition to 1 TD OCT scan via Stratus macular thickness protocol (software version 4.0; Carl Zeiss Meditec, Inc.). Scans were inspected for 6 types of OCT scan artifacts and were analyzed. Interscan reproducibility and interdevice agreeability were assessed by intraclass correlation coefficients (ICCs) and Bland-Altman plots, respectively. Optical coherence tomography image artifacts, macular thickness, reproducibility, and agreeability. Time-domain OCT scans contained a significantly higher percentage of clinically significant improper central foveal thickness (IFT) after manual correction (11-mum change or more) compared with SD OCT scans. Cirrus HD-OCT had a significantly lower percentage of clinically significant IFT (11.1%) compared with the other SD OCT devices (Topcon 3D, 20.4%; Topcon Radial, 29.6%; RTVue (E)MM5, 42.6%; RTVue MM6, 24.1%; P = 0.001). All 3 SD OCT devices had central foveal subfield thicknesses that were significantly more than that of TD OCT after manual correction (P<0.0001). All 3 SD OCT devices demonstrated a high degree of reproducibility in the central foveal region (ICCs, 0.92-0.97). Bland-Altman plots showed low agreeability between TD and SD OCT scans. Out of all OCT devices analyzed, cirrus HD-OCT scans exhibited the lowest occurrence of any artifacts (68.5%), IFT (40.7%), and clinically significant IFT (11.1%), whereas Stratus OCT scans exhibited the highest occurrence of clinically significant IFT. Further work on improving segmentation algorithm to decrease artifacts is warranted.

Repeatability and Reproducibility of Macular Thickness Measurements Using Fourier Domain Optical Coherence Tomography

Aim:To evaluate repeatability and reproducibility of macular thickness measurements in visually normal eyes using the Topcon 3D OCT-1000.Methods:Phase 1 investigated scan repeatability, the effect of age and pupil dilation. Two groups (6 younger and 6 older participants) had one eye scanned 5 times pre and post- dilation by 1 operator. Phase 2 investigated between-operator, within and between-visit reproducibility. 10 participants had 1 un-dilated eye scanned 3 times on 2 separate visits by 2 operators.Results:Phase 1:No significant difference existed between repeat scans (p=0.75) and no significant difference was found pre- and post-dilation (p=0.54). In the younger group variation was low (95% limits ± 3.62µm) and comparable across all retinal regions. The older group demonstrated greater variation (95% limits ± 7.6µm).Phase 2:For a given retinal location, 95% confidence limits for within-operator, within-visit reproducibility was 5.16µm. This value increased to 5.56µm for the same operator over two visits and to 6.18µm for two operators over two visits.Conclusion:A high level repeatability, close to 6µm, of macular thickness measurement is possible using the 3D OCT- 1000. Measured differences in macular thickness between successive visits that exceed 6µm in pre-presbyopic individuals are therefore likely to reflect actual structural change. OCT measures are more variable in older individuals and it is advisable to take a series of scans so that outliers can be more easily identified.

Diurnal variation of macular oedema in CRVO: prospective study

Patients with central retinal vein occlusion (CRVO) may experience reduced vision in the morning. This may be due to increased cystoid macular oedema (CMO), which can be measured on optical coherence tomography (OCT). A prospective study was performed on ten patients. Retinal thickness measurements were made with the Topcon 3D OCT-1000: at 9 A.M., 11 A.M., 1 P.M., 3 P.M., 5 P.M. In addition, at 9 A.M. and 5 P.M. visual acuity was recorded using ETDRS LogMAR. There were seven males and three females with average age of 59.4 years (range 40-80 years). The average duration of symptoms was 5.4 months (range 3-9 months). In eyes with CRVO, median central macular thickness (CMT) significantly reduced from 571 microm at 9 A.M. to 475 microm at 5 P.M. (p < 0.05). Comparison of CMT at 9 A.M. to each of the subsequent time intervals found that there was a significant reduction in the central macula thickness late in the day (p < 0.05). There was no statistical difference in the visual acuity and change in macular thickness did not correlate with change in visual acuity in eyes affected by CRVO. Patients with CRVO demonstrate increase in CMO in morning compared with late morning and afternoon. Possible causes are diurnal variation in blood pressure, retinal metabolism and erect posture. Interventions designed to influence these factors could be used to try to reduce CMO severity.

TOPCON 3D OCT 1000 reproducibility in normal and diabetic patients

Abstract Purpose TOPCON 3D OCT 1000 is a spectral domain OCT, used in our everyday’s practice. There are many studies reporting reproducibility of commercially available time domain OCTs. The reproducibility of spectral domain OCTs is expected to be better. To our knowledge there are no reproducibility studies with TOPCON 3D OCT 1000. Our purpose was to evaluate its reproducibility in normal and diabetic patients. Methods 10 normal maculae and 10 maculae with diabetic edema were scanned for 5 times. Data presented as retinal thickness and retinal volume were analyzed and statistically evaluated. Results TOPCON 3D OCT 1000 shows excellent reproducibility in normal patients. Differences in measured parameters in patients with diabetic macular edema are not statistically significant. Conclusion Retinal thickness and retinal volume measurements with TOPCON 3D OCT 1000 are very reliable, although care must be taken in interpreting small differences in pathologic conditions.

Features of age-related macular degeneration assessed with three-dimensional Fourier-domain optical coherence tomography

Background/aims:Age-related macular degeneration (AMD) is among the leading causes of severe visual loss in individuals over 60 years old. Retinal changes associated with AMD were previously studied by time-domain optical...