Eimei Ra

Sex-Related Differences in Ocular Blood Flow of Healthy Subjects Using Laser Speckle Flowgraphy.

PURPOSE To evaluate sex-related differences in ocular blood flow of healthy subjects using laser speckle flowgraphy (LSFG). METHODS In this prospective cross-sectional study, we examined 103 healthy volunteers (47 males, 56 females; mean age: 39.3 ± 15.6 years and 42.1 ± 18.7 years, respectively). The blood flow to the optic nerve head (ONH) and choroid was assessed with LSFG, including mean blur rate (MBR) and pulse waveform variables. We evaluated sex-related differences in these variables and compared them with those in other clinical parameters. RESULTS A linear single regression showed that the ONH-MBR (r = -0.402, P < 0.001) and five ONH pulse waveforms were significantly correlated with sex. A multiple stepwise regression analysis revealed that sex (β = 0.389, P < 0.001) and age (β = -0.290, P = 0.002) were independent factors, indicating the ONH-MBR, age (β = -0.394, P < 0.001), and subfoveal choroidal thickness (β = 0.221, P = 0.016) were independent factors indicating the choroidal MBR. Moreover, sex was an independent factor indicating the five ONH pulse waveform parameters that were consistent with results of the linear single regression. The optic nerve head MBR in the female group was significantly higher than that in the male group (P < 0.001), but no differences were observed in the choroid between the groups (P > 0.05). CONCLUSIONS Sex-related differences are present in ocular blood flow in the ONH, but not in the choroid in healthy subjects. We believe that these differences should be considered when interpreting blood flow data in ocular diseases.

Diurnal variations in blood flow at optic nerve head and choroid in healthy eyes: diurnal variations in blood flow.

AbstractTo investigate the diurnal variations of the ocular blood flow in healthy eyes using laser speckle flowgraphy (LSFG), and to determine the relationship of the diurnal variations between the ocular blood flow and other ocular parameters.This prospective cross-sectional study was conducted at Nagoya University Hospital. We studied 13 healthy volunteers whose mean age was 33.5 ± 7.6 years. The mean blur rate (MBR), expressing the relative blood flow, on the optic nerve head (ONH) and choroidal blood flow was determined by LSFG (LSFG-NAVI) every 3 hours from 6:00 to 24:00 hours. The intraocular pressure (IOP), choroidal thickness measured by enhanced depth imaging optical coherence tomography, systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) in the brachial artery were also recorded. We evaluated the diurnal variations of the parameters and compared the MBR to the other parameters using a linear mixed model.The diurnal variations of the MBR on the ONH varied significantly with a trough at 9:00 hours and a peak at 24:00 hours (P < 0.001, linear mixed model). The MBR of choroid also had significant diurnal variations with a trough at 15:00 hours and a peak at 18:00 hours (P = 0.001). The IOP (P < 0.001), choroidal thickness (P < 0.001), SBP (P = 0.005), DBP (P = 0.001), and HR (P < 0.001) also had significant diurnal variations. Although the diurnal variation of the MBR on the ONH was different from the other parameters, that on the choroid was significantly and positively correlated with the DBP (P = 0.002), mean arterial pressure (P = 0.023), and mean ocular perfusion pressure (P = 0.047).We found significant diurnal variations in the ONH and choroidal blood flow. Although the ONH blood flow had its own diurnal variation because of strong autoregulation, the choroidal blood flow was more likely affected by systemic circulatory factors because of poor autoregulation.

Association Between Photoreceptor Regeneration and Visual Acuity Following Surgery for Rhegmatogenous Retinal Detachment

PURPOSE The purpose of this study was to evaluate foveal regeneration and the association between retinal restoration and visual acuity following reattachment surgery for rhegmatogenous retinal detachment (RRD). METHODS Twenty-nine eyes of 29 patients with successfully reattached macula-off RRD were retrospectively analyzed. We used spectral-domain optical coherence tomography to image macular regions and measure retinal thickness and Snellen chart visual acuity (VA) to evaluate best-corrected VA (BCVA) at 1, 2, 3, 6, 9, and 12 months after vitrectomy. Best-corrected visual acuity data were converted to the logarithm of the minimum angle of resolution scale. Opposite eyes were used as controls. RESULTS The thicknesses of the external limiting membrane (ELM)-ellipsoid zone (EZ) and EZ-retinal pigment epithelium (RPE) were significantly thinner in involved eyes than in corresponding unaffected eyes at 1 month after surgery (P < 0.001 for both), and the thickness increased over time (P < 0.001 for both). Best-corrected visual acuity significantly improved over time (P < 0.001), and the improvement correlated with EZ-RPE thickness (r = -0.45, P = 0.021). Multiple regression analysis demonstrated the presence of a foveal bulge as the independent predictor of final BCVA (P < 0.001). Eyes with a foveal bulge had significantly better BCVA and greater EZ-RPE thickness than those without throughout the follow-up period. Significant restoration of the integrity of EZ and cone interdigitation zone (CIZ) was observed over time (P < 0.001 for both) in eyes with a foveal bulge. CONCLUSIONS The thickness of EZ-RPE and cone density increased during foveal regeneration, as demonstrated by the continuous improvements in CIZ integrity over time, leading to the formation of foveal bulge and good vision following successful reattachment of macula-off RRD.

Differences of Retinal Blood Flow Between Arteries and Veins Determined by Laser Speckle Flowgraphy in Healthy Subjects.

AbstractTo characterize the total retinal blood flow determined by laser speckle flowgraphy (LSFG) of healthy subjects.This prospective cross-sectional study was conducted at the Nagoya University Hospital. One hundred fifteen right eyes of 115 healthy subjects (mean age: 39.4 ± 16.1 years) were studied. The total blood flow in the retinal arteries and veins around the optic nerve head was measured separately using the total retinal flow index (TRFI), which represents blood flow volume. The lumen diameters of the retinal vessels determined by LSFG and by adaptive optics (AO) camera were compared. The images obtained by LSFG and AO camera were merged, and the distribution of the mean blur rates (MBRs), which represent the velocities of the erythrocytes, was evaluated on the images.The mean TRFI in veins (1812 ± 445, arbitral units) was significantly higher than that in arteries (1455 ± 348, arbitral units; P < 0.001). Linear regression analysis showed a significant correlation between the TRFI in the arteries and veins (P < 0.001). Linear regression analysis also showed a highly significant correlation between the diameters of arteries and veins determined by LSFG and by the AO camera (arteries, r = 0.94, P < 0.001; veins, r = 0.92, P < 0.001). The ratios of the lumen diameters determined by LSFG to that by AO camera was significant lower in arteries (0.068 ± 0.005, arbitral units) than in veins (0.074 ± 0.007, arbitral units) (P < 0.001). The MBRs of veins were homogeneous throughout the width of the lumen; however, the MBRs in the arteries were higher at the center and lower close to the walls of the lumen.The higher TRFIs in the veins than in the arteries indicate that there is a smaller volume of retinal blood flow in arteries than veins. However, the possibility remains that LSFG has inherent problem that the arterial lumen diameter determined by LSFG is smaller than actual one because of the characteristics of arteries. This would result in a smaller volume of retinal blood flow in the arteries than veins in LSFG.

Restoration of Cone Interdigitation Zone Associated With Improvement of Focal Macular ERG After Fovea-Off Rhegmatogenous Retinal Reattachment

PURPOSE To determine whether a correlation exists between the parameters of the focal macular ERGs (FMERGs) and the microstructural changes of the photoreceptors after successful surgery for fovea-off rhegmatogenous retinal detachment (RRD). METHODS Twenty eyes of 20 patients who had undergone successful surgery to reattach the retina in eyes with fovea-off RRD were studied. Focal macular ERGs and spectral-domain OCT (SD-OCT) were recorded at 1 and 6 months after the surgery. Changes of the components of the FMERGs, as well as changes of the SD-OCT parameters including the length of the external limiting membrane (ELM), ellipsoid zone (EZ), cone interdigitation zone (CIZ), and size of the outer photoreceptor area (between ELM and RPE), were determined. RESULTS During the postoperative period, the mean amplitudes of the a-waves increased by 1.4 times and the b-waves by 1.7 times. Spectral-domain OCT showed that the mean length of the EZ and CIZ and the size of the outer photoreceptor area had increased significantly at 6 months. The degree of the increase in the CIZ and outer photoreceptor area was significantly correlated with the increase in the amplitudes of the b-waves of the FMERGs (r = 0.56, P = 0.042, r = 0.57, P = 0.040, respectively; Spearman rank correlation test). However, the length of the EZ was not significantly correlated with the increase of the b-waves. CONCLUSIONS A restoration of the EZ alone might not be enough to improve the FMERGs, and a restoration of the EZ accompanied by that of the CIZ was essential for the recovery of the FMERGs after fovea-off RRD.

Effects of photocoagulation on ocular blood flow in patients with severe non-proliferative diabetic retinopathy

Purpose To investigate ocular blood flow and correlations between ocular blood flow and variables in patients with severe non-proliferative diabetic retinopathy (S-NPDR) following panretinal photocoagulation (PRP). Methods In this retrospective, cross-sectional study, the blood flow on the optic nerve head (ONH) and choroid was assessed with laser speckle flowgraphy (LSFG) using the mean blur rate (MBR) in 76 eyes of 76 patients with S-NPDR who underwent PRP, 39 eyes of 39 patients with S-NPDR who did not undergo PRP, and 71 eyes of 71 normal subjects. The correlation between MBR and variables, including visual acuity (VA) and choroidal area determined by binarization method, was analyzed. Results The mean age was 62.9 ± 11.9 years in the S-NPDR with PRP eyes, 55.6 ± 11.4 years in the S-NPDR without PRP eyes, and 60.3 ± 11.1 years in the normal subject eyes. The ONH MBR in vessel and tissue areas and the choroidal MBR were significantly lower in the S-NDR with PRP group than in the other groups (p < 0.001, p < 0.001, and p < 0.001, respectively). The luminal and the stromal areas were significantly smaller in the S-NDR with PRP group than in the other groups (p < 0.001 and p < 0.001, respectively). LogMAR best corrected visual acuity (BCVA) exhibited significant negative correlation with the ONH MBR in vessel (r = −0.386, p < 0.001), tissue (r = −0.348, p < 0.001), and the choroid MBR (r = −0.339, p = 0.002) in the S-NDR with PRP group. Stepwise multiple regression analysis demonstrated that BCVA was a common independent factor associated with the ONH MBR in vessel, tissue, and the choroidal MBR in the S-NDR with PRP group. Conclusions ONH and choroid MBR in addition to choroidal component, including the luminal area, were significantly lower in eyes of patients with S-NPDR after PRP compared with no PRP and normal subjects group. This could suggest that the significantly reduced ocular blood flow in PRP-treated S-NPDR eyes correlated with long-term decreased post-PRP luminal area and visual acuity.

Optical coherence tomography angiography in leber hereditary optic neuropathy.

treated using the same protocol and the difference in response may still reflect a variable reaction. It is possible that in unresponsive patients, switching to a higher frequency of aflibercept injections would result in a more favourable outcome (Arcinue et al. 2015). Whereas all our patients demonstrated a reduction in CRT following conversion, the visual function did not change accordingly, suggesting that in patients with continued visual deterioration despite anatomical stability, changing agents may be advised to achieve maximal therapeutic effect.

What ocular and systemic variables affect choroidal circulation in healthy eyes

Abstract The aim of the study was to investigate the relationship between choroidal blood flow and systemic and ocular variables in patients with healthy eyes. In this prospective cross-sectional study, we examined 241 eyes of 241 healthy Japanese subjects (92 males and 149 females; mean age, 37.8 ± 17.0 years). The mean blur rate, a measure of the relative blood flow of the choroid, was determined using laser speckle flowgraphy. The total cross-sectional choroidal, luminal, and stromal areas of the choroid were determined by the binarization method. We investigated the correlation between choroidal MBR and systemic and ocular variables. Choroidal mean blur rate correlated with age (r = −0.385, P < 0.001) and choroidal thickness (r = 0.264, P < 0.001). The choroidal area correlated with choroidal mean blur rate (r = 0.374, P < 0.001), age (r = −0.184, P = 0.004), axial length (r = −0.251, P < 0.001), and choroidal thickness (r = 0.468, P < 0.001). The luminal area correlated with choroidal mean blur rate (r = 0.403, P < 0.001), age (r = −0.244, P < 0.001), axial length (r = −0.218, P = 0.001), and choroidal thickness (r = 0.435, P < 0.001). On multiple stepwise regression analyses, age (&bgr; = −0.321, P < 0.001) and luminal area (&bgr; = 0.320, P < 0.001), heart rate (&bgr; = 0.136, P = 0.018), and mean ocular perfusion pressure (&bgr; = 0.126, P = 0.045) were independent factors indicating the choroidal mean blur rate. Furthermore, axial length (&bgr; = −0.352, P < 0.001), choroidal mean blur rate (&bgr; = 0.273, P < 0.001), age (&bgr; = −0.247, P < 0.001), gender (&bgr; = −0.226, P < 0.001), and mean ocular perfusion pressure (&bgr; = 0.193, P = 0.002) were independent factors indicating the luminal area. The choroidal blood flow positively correlated with the luminal area and negatively correlating with age. In addition, the luminal area was negative correlated with age. It is suggested that aging causes a reduction in choroidal blood flow and luminal area, and as a result of aging effect, decreased choroidal blood flow would correlate with decreased luminal area.

NEAR-INFRARED REFLECTANCE IMAGING IN EYES WITH ACUTE ZONAL OCCULT OUTER RETINOPATHY.

Purpose: To investigate the confocal scanning laser ophthalmoscopic images obtained with near-infrared (IR) light in eyes with acute zonal occult outer retinopathy (AZOOR). Methods: Observational case series. The medical records of 12 eyes of 10 patients with AZOOR were reviewed. Scanning laser ophthalmoscopic images obtained from the AZOOR eyes were compared with images obtained by spectral-domain optical coherence tomography, by fundus autofluorescence, and by an adaptive optics fundus camera. Results: In 8 of 12 eyes, abnormal hyporeflective areas were detected in the IR images, and the other 4 eyes did not have specific abnormalities in the IR images. The boundaries of the abnormal hyporeflective areas corresponded with the border of the irregularity of photoreceptor inner segment ellipsoid band in the spectral-domain optical coherence tomography images. The cone mosaics of the adaptive optics fundus image were disrupted in the abnormal hyporeflective area of the IR image. However, the areas of fundus autofluorescence abnormalities did not coincide with the hyporeflective areas in the IR images. Conclusion: The presence of hyporeflective areas in the IR images of patients with AZOOR suggests impairment of the photoreceptors area. The IR images would be useful to evaluate eyes with AZOOR.

Comparison between 1-year outcomes of aflibercept with and without photodynamic therapy for polypoidal choroidal vasculopathy: Retrospective observation study

Polypoidal choroidal vasculopathy (PCV) is characterized by polyp-like choroidal neovascularization and a branching vascular network. Intravitreal aflibercept injection (IAI) or photodynamic therapy (PDT) is used for treatment. We retrospectively compared the 1-year outcomes of IAI monotherapy and its combination with initial PDT for PCV. Twelve eyes with naïve PCV received three IAIs and a single PDT after the first IAI and as needed injection (combination group); 11 eyes with naïve PCV received three IAIs and as needed injections (IAI group). Significant improvements in visual acuity after 2 months and in CRT after 1 month were maintained at 12 months in both groups (both P < 0.05); groups did not differ significantly at any time point. CCT significantly reduced after 3 and 12 months in the combination group (both P < 0.05) but not in the IAI group. A mean of 3.7 ± 0.9 and 5.6 ± 2.0 injections was administered to the combination and IAI groups, respectively (P = 0.013). Within a 1-year period, combination therapy was found to yield similar visual acuity and retinal structure improvements and maintenance as IAI monotherapy while requiring fewer IAIs.