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BACKGROUND AND OBJECTIVE:To compare macular thickness measurement algorithms of two different spectral-domain optical coherence tomography (SD-OCT) devices in eyes affected by dry age-related macular degeneration (AMD).PATIENTS AND METHODS:Patients with dry AMD and healthy volunteers from the retina clinic of the Doheny Eye Center – UCLA were imaged using two different SD-OCT devices: the RS-3000 Advance (Nidek, Padova, Italy) and the Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA). All patients had been previously diagnosed with drusen or geographic atrophy due to AMD. The commercial instrument software was used to generate the macular retinal thickness measurements, and measurements were compared between devices.RESULTS:Eighty-five diseased eyes from 49 patients and 16 healthy control eyes from eight normal volunteers were included in this study. The macular thickness measurements generated by the two instruments in eyes with AMD differed significantly in mean retinal thickness in the foveal center subfield (257.34 μm ± 51.72 μm using the Nidek OCT vs. 238.20 μm ± 51.89 μm using the Cirrus OCT; Eighty-five diseased eyes from 49 patients and 16 healthy control eyes from eight normal volunteers were included in this study. The macular thickness measurements generated by the two instruments in eyes with AMD differed significantly in mean retinal thickness in the foveal center subfield (257.34 μm ± 51.72 μm using the Nidek OCT vs. 238.20 μm ± 51.89 μm using the Cirrus OCT; P< .001). The mean difference in macular thickness between the two devices was 19.14 μm ± 5.84 μm for diseased eyes and 17.06 μm ± 5.28 μm in normal control eyes, and this was not statistically different between the two groups (P> .05). The macular thickness measurements in diseased eyes, as evaluated by the two different instruments, however, showed excellent correlation (r = 0.99; P< .001), with an intraclass correlation coefficient of 0.99 (95% confidence interval, 0.98–0.99). Post hoc evaluation of cases with larger differences also showed differences in foveal center selection and variabilities in boundary selection with specific pathology.CONCLUSION:Macular thickness measurements provided by the Nidek and Cirrus OCT instruments in eyes with dry AMD are highly correlated but show a consistent difference, which may allow the use of a standard correction factor to be applied to better interrelate measurements between the devices.[[Ophthalmic Surg Lasers Imaging Retina. 2018;49:410–415.]

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BACKGROUND AND OBJECTIVE:To compare macular vessel density (VD) and foveal avascular zone (FAZ) area in healthy individuals using two different optical coherence tomography angiography (OCTA) devices.PATIENTS AND METHODS:In this prospective, comparative study, 25 eyes of 14 healthy subjects underwent fovea-centered 3 mm × 3 mm OCTA-imaging using the Triton (Topcon, Tokyo, Japan) and RS-3000 (Nidek, Gamagori, Japan) OCTA devices. Superficial and deep retinal layers (SRL/DRL) and FAZ were manually graded after threshold standardization to determine macular VD and area of the FAZ.RESULTS:The mean difference in the VD between the two devices was 0.105 and 0.096, and the coefficient of variation (CV) was 19.59% and 16.90% for the SRL and DRL, respectively. After skeletonization of vessels to remove variation related to vessel width, the mean difference was 0.174 mmThe mean difference in the VD between the two devices was 0.105 and 0.096, and the coefficient of variation (CV) was 19.59% and 16.90% for the SRL and DRL, respectively. After skeletonization of vessels to remove variation related to vessel width, the mean difference was 0.174 mm−1and 0.516 mm−1, and the CV was 3.49% and 1.07% for SRL and DRL, respectively. The mean difference of FAZ area was 0.001 mm2and 0.010 mm2in the SRL and DRL, respectively, and the CV was 2.17% and 5.74% for the SRL and DRL, respectively.CONCLUSION:Macular VD using skeletonized mapping and FAZ area in SRL and DRL were statistically similar between the two devices, demonstrating a possible comparison of quantitative values between different OCTA devices.[[Ophthalmic Surg Lasers Imaging Retina.2017;48:385–391.]

BACKGROUND AND OBJECTIVE:To determine the correlation between mesopic retinal sensitivity and optical coherence tomographic metrics of the outer retina in patients with intermediate age-related macular degeneration (AMD).PATIENTS AND METHODS:Participants with nonatrophic dry AMD underwent mesopic MP-3 microperimetry (Nidek, Padova, Italy) and both Nidek and Cirrus (Carl Zeiss Meditec, Dublin, CA) spectral-domain optical coherence tomography (SD-OCT). The volume of the outer retinal layers was measured on the Nidek SD-OCT scans using the automatic segmentation algorithm of Navis-EX software. In addition, drusen area and volume within a 5-mm circle centered on the fovea were determined using the Cirrus Advanced RPE Analysis Tool. The mean retinal sensitivity at 8° and 10° of fixation (5-mm and 6-mm circles) was calculated for every eye. The correlation between retinal sensitivity and patient age, outer retinal layer volume, drusen area, and drusen volume was assessed.RESULTS:Thirty-seven eyes from 25 patients with non-atrophic dry AMD were included in the study. The mean age of the patients was 76 years ± 9 years. The mean sensitivity across the whole tested retinal area was 24.9 dB ± 2.4 dB, with a sensitivity of 25.1 dB ± 2.4 dB within the central 5-mm circle. Drusen area within the central 5-mm circle was 0.7 mmThirty-seven eyes from 25 patients with non-atrophic dry AMD were included in the study. The mean age of the patients was 76 years ± 9 years. The mean sensitivity across the whole tested retinal area was 24.9 dB ± 2.4 dB, with a sensitivity of 25.1 dB ± 2.4 dB within the central 5-mm circle. Drusen area within the central 5-mm circle was 0.7 mm2± 0.89 mm2with a drusen volume of 0.03 mm3± 0.04 mm3. Retinal pigment epithelium and photoreceptor outer segment (RPE + OS) volume was 1.96 mm3± 0.1 mm3, and outer nuclear layer (ONL) volume was 1.91 mm3± 0.17 mm3. There was a significant correlation between RPE + OS volume and retinal sensitivity, as well as between patients' age and retinal sensitivity. There was no significant correlation between drusen area or volume and retinal sensitivity, nor between ONL volume and retinal sensitivity.CONCLUSION:In eyes with nonatrophic AMD, retinal sensitivity is correlated with the RPE + OS volume, but not the ONL volume or the area or volume of drusen.[[Ophthalmic Surg Lasers Imaging Retina.2017;48:312–318.]

AimsTo determine the repeatability of optical coherence tomography angiography (OCT-A)-derived automated vessel density measurements in the superficial retinal layer (SRL) and deep retinal layer (DRL) in healthy individuals.Methods41 eyes of 21 healthy individuals were included in this study. OCT-A was performed using the NIDEK RS-3000 Advance with prototype OCT-A software. Each subject underwent two scanning sessions with 5–10 min in between. En face images of the retinal vasculature were generated using the default segmentation for SRL and DRL. Automated vessel density measurements were compared between the two sessions. The intraclass correlation coefficients (ICCs) and coefficient of repeatability were used as a measure for repeatability.ResultsThe mean±SD age of the subjects was 36.8±7.5 years. Overall vessel density measured in the first and second session was 19.43±3.10 and 19.72±3.78 for the SRL, and 34.67±1.801 and 34.55±1.64 for the DRL, respectively. The mean difference in vessel density between sessions was −0.3 (95% CI 3.3 to −3.9) for the SRL and 0.1 (95% CI 2.6 to −2.5) for the DRL. The two measurements were highly correlated with an ICC=0.90 (p=0.33) for the SRL and 0.83 (p=0.589) for the DRL. The coefficient of variation was 0.052 for the SRL and 0.02 for the DRL.ConclusionsCommercial automated vessel density measurements using OCT-A showed excellent repeatability in healthy individuals. Although repeatability will also need to be established in the setting of disease, the level of reproducibility should be useful for assessing the significance of differences in capillary density over time or under different conditions.