Evaluating the relationship between ocular blood flow and systemic organ blood flow in hemorrhagic shock using a rabbit model.

This study aimed to investigate the feasibility of utilizing noninvasive ocular blood flow measurements as potential indicators of systemic circulation in rabbits experiencing hemorrhagic shock. Using Laser speckle flowgraphy, ocular blood flow indices, relative flow volume (RFV), and mean blur rate in the choroidal area (MBR-CH) were assessed in New Zealand White rabbits (n = 10) subjected to controlled blood removal and return. Hemodynamic parameters and biochemical markers were monitored alongside ocular circulation during blood removal and return phases. Additionally, correlations between ocular parameters and systemic indices were examined. The results indicated that RFV and MBR-CH exhibited significant correlations with renal and intestinal blood flows, with stronger correlations observed during blood removal. Additionally, ocular blood flow changes closely mirrored systemic dynamics, suggesting their potential as real-time indicators of shock progression and recovery. These findings indicate that ocular blood flow measurements may serve as real-time indicators of the systemic circulation status during hemorrhagic shock, offering potential insights into shock management and guiding tailored interventions. Thus, noninvasive ocular blood flow evaluation holds promise as an innovative tool for assessing systemic circulation dynamics during hemorrhagic shock.

Novel superpixel method to visualize fundus blood flow resistivity in healthy adults.

We aimed to perform superpixel segmentation of ocular blood flow maps obtained using laser speckle flowgraphy (LSFG) and investigate the effects of systemic parameters such as body weight, height, and sex on ocular blood flow resistivity. We studied 757 healthy participants (583 men, 174 women). We calculated the average beat strength over mean blur rate (BOM) as a LSFG resistivity index, as a function of age and sex using ordinary regions of interest (ROI) centered on the optic nerve head (ONH), the retinal vessels region and tissue around the ONH, and the choroid (CHD). We compared the ROI and superpixel-based methods, which are segmented based on image processing, for calculating the BOM. The sex differences in the BOM for the ONH, retinal-vessels region and tissue region of the ONH and CHD were significant for individuals aged ≤ 50 years (P < 0.01) but not those > 50 years old (P > 0.05). The average BOMs calculated using the ROI and superpixel methods were strongly correlated in the ONH (coefficient = 0.87, R2 = 0.8, P < 0.0001, n = 5465). In summary, a superpixel-segmented BOM map is suitable for two-dimensional visualization of ocular blood flow resistivity.

Effects of aging and exercise habits on blood flow profile of the ocular circulation.

PURPOSE: We examined the effects of aging and exercise habits on the ocular blood flow (OBF) and its profiles throughout the optic nerve head region and choroidal area. We hypothesized that exercise habits reduce the stiffness of vessels in the ocular circulation, which generally increases with aging. METHODS: Participants in a medical checkup program (698 males and 192 females aged 28 to 80 years) were categorized into 2 groups (with and without exercise habits) based on participant self-reporting and the definition of the Ministry of Health, Labor and Welfare of Japan (MHLW). OBF in the right eye was measured and analyzed using laser speckle flowgraphy. The blowout time (BOT), which is the time during which the blood flow is higher than half of the mean of the minimum and maximum signals during one heartbeat, was calculated as an index of the blood flow profile. BOT has been used as an indicator of the flexibility of blood vessels. RESULTS: BOT significantly decreased with aging. Neither the self-reported nor MHLW-based exercise habits significantly affected the ocular circulation. CONCLUSION: These results indicate that the stiffness of the ocular vessels increases with aging, and this cannot be prevented by exercise habits.

Characteristics of laterality in the optic nerve head microcirculation obtained by laser speckle flowgraphy in healthy subjects.

PURPOSE: To determine the characteristics of the laterality of the ocular microcirculation parameters obtained from laser speckle flowgraphy (LSFG) in the optic nerve head (ONH). SUBJECTS AND METHODS: We reanalyzed a total of 240 healthy subjects (169 men, 71 women) who had participated in a medical checkup program. We analyzed the average mean blur rate (MBR), maximum MBR (Max-MBR), minimum MBR (Min-MBR), and area ratio of the blood stream (ARBS). As the pulse waveform parameters, we also calculated the skew, blowout score (BOS), blowout time (BOT), rising rate, falling rate, flow acceleration index (FAI), acceleration time index (ATI), resistivity index (RI), and beat strength over MBR (BOM). All parameters were compared between left and right eyes. RESULTS: MBR-average, MBR-Max, MBR-Min, ARBS, skew, BOT, rising rate, falling rate, FAI, ATI, and ARBS did not differ significantly between the right and left eyes. The BOS in the right eyes was significantly lower than that of the left eyes, and the RI and BS in the right eyes were significantly higher than those of the left eyes. Similarly, for the whole of the ONH, the BOS in the tissue area (Tissue) and in the vessel area (Vessel) of the right eyes were significantly lower than those of the left eyes, and RI-Tissue, RI-Vessel, BOM-Tissue, and BOM-Vessel in the right eyes were significantly higher than those of the left eyes. CONCLUSION: By using LSFG, we observed laterality of the BOS, RI, and BOM, all of which are pulse wave form parameters in the ONH.

Real-Time Evaluation of Regional Arterial Stiffening, Resistance, and Ocular Circulation During Systemic Administration of Adrenaline in White Rabbits.

Purpose: To evaluate continuous variations of ocular microcirculation by laser speckle flowgraphy and those of regional stiffening by pulse wave velocity (PWV) and vascular resistance under systemic adrenaline administration in rabbits. Methods: Six 16-week-old male rabbits were evaluated. The mean blur rates in the retinal vessel (MBR-RV) and choroid (MBR-CH) were measured. We assessed blood pressure (BP), femoral and carotid vascular resistance, and the heart-ankle (ha)-PWV, heart-femoral (hf)-PWV, and femoral-ankle (fa)-PWV. Adrenaline (100, 300, and 1000 ng/kg) was intravenously administered over a 10-minute period during which the parameters were measured simultaneously every 2 minutes. Results: The MBR-RV and MBR-CH values were dose-dependently increased by the adrenaline in parallel with increased BP. At the load of 100 ng/kg adrenaline, the ΔMBR-RV and ΔMBR-CH showed positive correlations with the variation rate in mean arterial blood pressure. Also, the variation rate in carotid vascular resistance and the Δfa-PWV and Δhf-PWV were significantly positively correlated with both the ΔMBR-RV and ΔMBR-CH. At the 300-ng/kg phase, the correlations between the Δha-PWV and both ΔMBR-RV and ΔMBR-CH were canceled; instead, the Δhf-PWV showed a significant negative correlation with the ΔMBR-RV and ΔMBR-CH. At the 1000-ng/kg phase, Δha-PWV again showed significant positive correlations with the ΔMBR-RV and ΔMBR-CH. Conclusions: These results indicate the possibility that under a systemic administration of adrenaline in rabbits, not only the BP value but also the vascular resistance and arterial function are related to the variation in ocular microcirculation. Translational Relevance: A real-time evaluation system of systemic regional arterial function and ocular microcirculation in rabbits was developed.

The influence of hemorrhagic shock on ocular microcirculation by obtained by laser speckle flowgraphy in a white rabbit model.

PURPOSE: To clarify the continuous changes in the retinal vessels' and choroid's microcirculation during hemorrhagic shock and resuscitation in a rabbit model. METHODS: Hemorrhagic shock by the removal of blood (30 mL) and resuscitation by a blood-return technique was induced in anesthetized male New Zealand White rabbits (n = 10). We evaluated the retinal vessel blood flow (relative flow volume: RFV) and choroidal blood flow (mean blur rate in the choroid area: MBR-CH) by laser speckle flowgraphy (LSFG), with simultaneous measurements of systemic hemodynamics and laboratory parameters. RESULTS: RFV and MBR-CH showed significant decreases immediately after the initiation of blood removal and recovered by blood return. The lactate concentration tended to increase from baseline by the blood-removal operation, and it was significantly higher at the end of observation period. The %RFV and %MBR-CH each showed a significant positive correlation with mean arterial blood pressure, cardiac output, carotid blood flow, and central venous pressure. %RFV showed a significant positive correlation with %central venous oxygen saturation and negatively correlated with %lactate. The %hemoglobin did not show a significant correlation with %RFV or %MBR-CH. CONCLUSION: This rabbit hemorrhagic shock model confirmed that ocular microcirculation measurements by LSFG feasibly reflect variations in systemic hemodynamics during hemorrhagic shock and recovery.

Characterization of laser speckle flowgraphy pulse waveform parameters for the evaluation of the optic nerve head and retinal circulation.

To characterize laser speckle flowgraphy (LSFG) pulse waveform parameters for ocular circulation evaluation, a multicenter, prospective, cross-sectional study was conducted in 111 eyes of 86 healthy Japanese individuals. Optic nerve head (ONH) tissue-area, vessel-area mean blur rate (MT and MV, respectively), and MT and MV pulse waveform parameters were obtained using LSFG and ONH structural parameters using planimetry. Multivariate linear mixed-effects modeled regression analysis identified factors contributing to MT- or MV-waveforms using age, gender, smoking history, body mass index, systolic and diastolic blood pressure, heart rate, intraocular pressure, axial length, disc, rim, and ß-peripapillary atrophy areas, MT or MV, central retinal artery, and vein equivalents (CRAE and CRVE) as explanatory variables. MT- and MV-waveforms significantly correlated with one or more systemic factors, consistent with previous studies. Following confounding factor adjustment, MT-Skew significantly negatively correlated with ß-PPA area (P = 0.026); MT- and MV-flow acceleration index positively correlated with CRAE, MT, and MV (P = 0.041-< 0.001), compatible with these parameters' observed correlations to systemic factors. Significantly negative correlations of the blowout score and acceleration time index to CRAE partly conflicted with their correlations to systemic factors, and other waveform parameters showed little correlation to ocular factors. Thus, Skew and flow acceleration index assisted the in vivo ocular circulation characterization.

Ocular and Systemic Factors Affecting Laser Speckle Flowgraphy Measurements in the Optic Nerve Head.

Purpose: To investigate the ocular and systemic factors related to glaucoma and to be adjusted for interindividual comparison of ocular blood flow measurement results by laser speckle flowgraphy (LSFG) obtained from the optic nerve head (ONH) in normal Japanese individuals. Methods: A multicenter, prospective cross-sectional study was conducted. The ONH tissue-area and vessel-area mean blur rate (MT and MV) were evaluated using LSFG and ONH structural parameters using planimetric methods. Multivariate linear mixed-effects modeled regression analysis was used to identify the contributing factors to the MT and MV. The explanatory variables were age; gender; smoking history; body mass index; mean arterial pressure (MAP); heart rate; intraocular pressure; axial length (AL); disc, rim, cup, and ß-peripapillary atrophy (ß-PPA) areas; and central retinal artery and vein equivalents. Results: In total, 195 eyes of 126 healthy individuals with an average age of 48.1 years were included. Multivariate analysis showed that MAP and disc area had a negative (P < 0.001) correlation, whereas ß-PPA area had a positive correlation with MT (P = 0.010). Age and AL had a negative correlation (P = 0.001 and P = 0.011, respectively), whereas cup area had a positive correlation (P = 0.012) with MV. Conclusions: Interindividual comparison of MT or MV must be adjusted for both systemic factors (blood pressure or age) and local ocular factors (AL and disc, cup, or ß-PPA area). Translational Relevance: Our results provided reference data on the LSFG measurement and are important in comparing ocular blood flow between individuals using LSFG.

Gender differences in the influence of obstructive sleep apnea on optic nerve head circulation.

We investigated gender differences in the optic nerve head (ONH) microcirculation status in association with obstructive sleep apnea (OSA) by using laser speckle flowgraphy (LSFG). We evaluated 150 men (60.5 ± 11.0 yrs) and 45 women (63.0 ± 10.6 yrs) who underwent overnight polysomnography. The mean blur rate (MBR), maximum (Max) MBR, and minimum (Min) MBR were evaluated. The parameters were analyzed separately for the tissues, vessels, and throughout the ONH (All). The apnea hypopnea index (AHI: times/hr), the lowest SpO2%, and the mean SpO2% were calculated as indicators of OSA. We investigated which MBR sections are correlated with OSA parameters separately in the men and women. All MBR sections in the women were significantly positively correlated with the lowest SpO2. In the men, no MBR section was correlated with any OSA parameters. The factors contributing independently to MBR-Tissue were height (ß = 0.31) and lowest SpO2 (ß = 0.30). The lowest SpO2 in the women was significantly positively correlated with Max MBR-Tissue, Max MBR-All, and Min MBR-All. Our results confirmed a gender difference in characteristics of ONH microcirculation in association with OSA.

Influence of age and gender on the pulse waveform in optic nerve head circulation in healthy men and women.

The influences of age and gender differences on the pulse waveform in the optic nerve head (ONH) in healthy adults, using laser speckle flowgraphy (LSFG) were evaluated. We studied 908 healthy subjects (men = 701, age: 50.0 ± 9.1, women = 208, age: 49.8 ± 9.5, p = 0.76), evaluating these pulse waveform parameters: the blowout score (BOS), blowout time (BOT), acceleration time index (ATI), and the rising and falling rates. The parameters were analyzed separately for the tissue, vessels, and throughout the optic nerve head (All). All parameters were compared between genders. We investigated which independent factors for the pulse waveform in the ONH is most strongly correlated with age. All sections of the BOS, BOT, ATI, and falling rate showed a significant gender difference. A univariate regression analysis revealed that BOT-Tissue showed the strongest correlation with age (r = -0.51). The factors contributing independently to the BOT-Tissue were gender, age, heart rate, mean arterial blood pressure, pulse pressure, spherical refraction, and estimated glomerular filtration rate. Among the subjects aged >41 years, the chronological changes of BOT-Tissue in the women were significantly lower than those in the men. We concluded that the pulse waveform in the ONH has clear differences between the genders and shows chronological changes.

The influences of gender and aging on optic nerve head microcirculation in healthy adults.

Potential differences in the nature of the influences of aging and gender on the optic nerve head (ONH) microcirculation, using laser speckle flowgraphy (LSFG) were evaluated. We studied 908 healthy subjects (men = 701, age: 50.0 ± 9.1 yrs, women = 208, 49.8 ± 9.5 yrs, p = 0.76). The average, maximum (Max), and minimum (Min) mean blur rate (MBR) in a heartbeat were evaluated. The parameters were analyzed separately for the tissue, vessels, and throughout the ONH (All). We investigated which MBR sections are correlated with gender and age by univariate and multivariate regression analyses. The Max MBR-All (r = -0.31) was most strongly correlated with gender (men = 1, women = 0). The Min MBR-All (r = -0.24) was most strongly correlated with age, followed by Min MBR-All (r = -0.20). The factors contributing independently to the Max MBR-All were gender (ß = -0.15), pulse pressure, spherical refraction, ocular perfusion pressure, and red blood cell (RBC) count. The factors contributing independently to the Min MBR-Vessel were gender (ß = -0.09), age (ß = -0.25), body mass index, heart rate, and spherical refraction. The factors contributing independently to the Min-MBR-All were age (ß = -0.22), heart rate, and RBC count. Our results revealed that gender differences influence the Max MBR, and aging influences the Min MBR. These correlations were stronger than that of average MBR.

Sleep-Disordered Breathing Is a Stronger Risk Factor for Proliferative Diabetic Retinopathy than Metabolic Syndrome and the Number of Its Individual Components.

PURPOSE: To evaluate whether the features of sleep-disordered breathing (SDB) are stronger independent factors for proliferative diabetic retinopathy (PDR) compared to the incidence of metabolic syndrome (MetS) and the number of its individual components. METHODS: We studied a cross-sectional total of 132 patients with type 2 diabetes. Thirty-nine patients had non-proliferative diabetic retinopathy (NPDR) and 93 patients had PDR. Pulse oximetry was conducted, and the patients' mean oxygen saturation (mean SpO2%) and 4% oxygen desaturation index (4% ODI times/hour) were evaluated. We compared the SDB and MetS variables between the NPDR and PDR patients. A logistic regression analysis was used to determine the independent factors for the diagnosis of PDR. RESULTS: The MetS diagnosis was made significantly more often in the PDR group (p = 0.04). The number of individual MetS components was significantly greater in the PDR group compared to the NPDR group (p = 0.01). The mean SpO2 of the NPDR group was not significantly different from that of the PDR group. The 4% ODI in the NPDR group was significantly lower than that in the PDR group (p = 0.01). The logistic regression analysis using the prevalence of MetS and the number of MetS components revealed that younger age and high 4%ODI value were independent factors contributing to the diagnosis of PDR. CONCLUSION: Our findings confirmed that compared to MetS and the number of its individual components, SDB may be a factor contributing to the progression to PDR. However, further careful longitudinal validation studies are needed.

Pulse Waveform Analysis in Ocular Microcirculation by Laser Speckle Flowgraphy in Patients with Left Ventricular Systolic and Diastolic Dysfunction.

PURPOSE: To determine: (1) whether variables of a pulse wave form analysis of ocular microcirculation shown by laser speckle flowgraphy (LSFG) correlate with left ventricular (LV) systolic dysfunction and (2) whether these variables correlate with LV diastolic dysfunction in subjects without LV systolic dysfunction as assessed by echocardiography. METHODS: We studied 200 consecutive subjects. LV systolic dysfunction has been determined to be present when the LV ejection fraction was < 50%. LV diastolic dysfunction was diagnosed when subjects had an E/e' ratio ≥15 and an e' velocity < 10 cm/s. We evaluated the pulse waveform analysis variables "rising rate" and the blowout score (BOS) using LSFG in the optic nerve head (ONH) and choroid. RESULTS: The brain natriuretic peptide (BNP) level, the rising rate in the choroid area (rising rate-choroid), and heart rate were revealed as independent factors for LV systolic dysfunction, and BOS-choroid was identified as an independent factor for LV diastolic dysfunction. The areas under the curve (AUC) of BNP and rising rate-choroid for LV systolic dysfunction were 0.83 and 0.81, respectively. The AUC of BOS-choroid for LV diastolic dysfunction was 0.73. CONCLUSION: Pulse waveform analysis in the choroid has a significant correlation with LV systolic and LV diastolic function.

Relationships between retinal break locations and the shapes of the detachments.

PURPOSE: Detecting primary breaks and confirming detachment preoperatively are important. Lincoff stated that retinal detachments progress according to gravity; his law has become popular. We evaluated Lincoff's law with a slight modification to determine whether it remains suitable for present cases independent of refractive error and previous cataract surgery. PATIENTS AND METHODS: Group 1 included superior region detachments not exceeding the 12 o'clock midline; the original break was within 1 1/2 clock hours of the highest detachment border. Group 2 included shallow inferior detachment; the original break corresponded to the more spread side of the 6 o'clock midline. Group 3 detachments were beyond 12 o'clock; the original break was within a triangle with a 12 o'clock apex (A) or within 1 1/2 hours of 12 o'clock (B); (A) and (B) were stated in the original report. Another five classifications were applied for small numbers of detachments. Consecutive initial rhegmatogenous retinal detachment surgery patients were included; medical records and detachment charts were examined. Eyes were classified into categories and rates were calculated. Eyes that had never undergone previous cataract surgery besides those in which the macula remained attached were divided into groups at a -6 D cutoff (Groups 1, 2, and 3[B]); we compared groups in each category. We compared phakic eyes, pseudophakic eyes, and eyes ruptured at the posterior capsule (Groups 1, 2, and 3[B]). RESULTS: Finally, 747 eyes were categorized. In Groups 1, 2, 3(A), and 3(B), corresponding rates were 92, 86, 70, and 89%, respectively. Between the above and below -6 D groups, there was no significant difference in rate in any category. There were no significant differences between phakic, pseudophakic, and ruptured eyes. CONCLUSION: Lincoff's law was suitable for the present cases and independent of refractive error and previous cataract surgery.

Assessment of ocular microcirculation in patients with end-stage kidney disease.

PURPOSE: To determine the impact that end-stage kidney disease (ESKD) has on ocular microcirculation in the optic nerve head (ONH) and choroid area shown by laser speckle flowgraphy (LSFG). METHODS: We studied 24 consecutive Japanese patients with ESKD who visited the department of Nephrology at our hospital and 55 age- and gender-matched subjects who had undergone polysomnography. The mean blur rates (MBRs) in vessels (MBR-Vessel), in the tissue (MBR-Tissue), throughout the ONH (MBR-All), and throughout the choroid (MBR-Choroid) were analyzed. We divided the MBR-Tissue into four sections (superior, temporal, inferior, and nasal). The results of systemic and ocular parameters were compared between the ESKD patients and control subjects. We performed single and multiple regression analyses to determine the MBR section(s) that correlated most strongly with serum creatinine and the estimated glomerular filtration rate (eGFR) and to identify the independent factors for selected MBR sections in the ESKD patients. RESULTS: All sections of the ONH in the ESKD patients were significantly lower than those in the control subjects. MBR-Choroid was not significantly different between the control and ESKD groups. The single regression analyses revealed that MBR-Tissue had the strongest correlations with creatinine and the eGFR. The multiple regression analyses revealed hematocrit, creatinine, and eGFR as factors independently contributing to the MBR-Tissue. The inferior section of MBR-Tissue was most strongly correlated with creatinine and the eGFR. CONCLUSION: The MBRs in the ONH of the ESKD patients decrease compared with control subjects and the inferior section of MBR-Tissue is correlated with serum creatinine and eGFR.

Intravitreal bevacizumab treatment reduces ocular blood flow in retinopathy of prematurity: a four-case report.

PURPOSE: To evaluate the relationship between ocular blood flow, expressed as mean blur rate (MBR) by laser speckle flowgraphy, and intravitreal bevacizumab (IVB) therapy in neonates with retinopathy of prematurity (ROP). METHODS: This was a case series study of 4 neonates with ROP under sedation before and after IVB and evaluated 8 eyes, in which the circulation could be measured three times consecutively. We performed optic nerve head blood flow measurement and fluorescein angiography (FA) before and 1 week after treatment. Blood flow was analyzed separately for MBR-A (mean of all values), MBR-V (vessel mean), and MBR-T (tissue mean). Comparisons between the MBR (-A, -V, -T), body weight, and other systemic and ocular parameters before and after treatment were performed using a paired t test. RESULTS: The MBR values after IVB were lower than the pre-treatment values in all cases. All eyes showed leakage at neovascularization on FA before treatment. Although leakage improved 1 week after treatment, the neovascularization did not completely regress. CONCLUSIONS: IVB improves vein dilation and artery tortuosity, while reducing ocular blood flow in neonates with ROP. We suggest that neovascularization might not be involved in reducing ocular blood flow in the early stage of IVB treatment.

The relationships between the pulsatile flow form of ocular microcirculation by laser speckle flowgraphy and the left ventricular end-diastolic pressure and mass.

To evaluate the relationships between parameters of the pulsatile flow form in the optic nerve head shown by laser speckle flowgraphy (LSFG) and the left ventricular (LV) end-diastolic pressure and mass obtained by echocardiography. We cross sectional analyzed the cases of 175 subjects who had undergone polysomnography. Standard M-mode two-dimensional color Doppler imaging was performed to evaluate the E/e' ratio (which represents the LV end-diastolic pressure) and LV mass. The pulsatile flow form analysis parameters of the blowout score and acceleration time index were evaluated. The parameters were analyzed separately for the tissue, vessels and throughout the optic nerve head (All). We performed a single regression analysis and a multiple regression analysis to determine whether pulsatile flow form are independent factors for the E/e' ratio and LV mass. The factors contributing independently to the E/e' ratio were blowout time-Tissue (standard regression = - 0.27, t-value = - 2.90, p < 0.0001) and body mass index (BMI) (0.16, 2.05, p = 0.04). The factors that were shown to independently contribute to the LV mass were urinary albumin concentration (0.30, - 2.90, p < 0.0001), BMI (0.28, 4.09, p < 0.0001), differences of gender (men = 1, women = 0: 0.23, 3.28, p = 0.001), acceleration time index-Vessel (- 0.23, - 2.99, p = 0.003) and mean arterial blood pressure (0.17, 2.61, p = 0.01). Our results confirmed that parameters of the pulsatile flow form of ocular microcirculation obtained by LSFG are significantly correlated with the LV end-diastolic pressure ratio and LV mass.

Relationship between Metabolic Syndrome and Ocular Microcirculation Shown by Laser Speckle Flowgraphy in a Hospital Setting Devoted to Sleep Apnea Syndrome Diagnostics.

PURPOSE: To clarify whether the incidence of metabolic syndrome (MetS) and the overlap of MetS components are affecting the ocular circulation shown by laser speckle flowgraphy (LSFG). MATERIALS AND METHODS: We studied 76 consistent patients. Blowout score (BOS) and blowout time (BOT), which are the pulse waveform analysis parameters, and mean blur rate (MBR) using LSFG in the optic nerve head (ONH) and choroid were evaluated. Throughout, the ONH was separated out from the vessels and tissue for analysis and MBRs in the ONH were divided into four sections (superior, temporal, inferior, and nasal). RESULTS: Thirty-two patients were diagnosed having Mets. MBR-Tissue (P = 0.003), MBR-All (P = 0.01), MBR-Choroid (P = 0.04), and BOS-Choroid (P = 0.03) were significantly lower in patients with MetS than in the patients without MetS. Multiple-regression analysis revealed the temporal side of MBR-Tissue and BOS-Choroid which were identified as factors contributing independently to the overlap of the MetS components. Multiple-regression analysis also revealed that the MetS components were identified to be factors independently contributing to the BOS-Choroid and temporal side of MBR-Tissue. CONCLUSION: Our study clarified that the incidence of MetS and the overlap of the MetS components are significantly affecting the ONH and choroidal microcirculation.

Decreased ocular blood flow after photocoagulation therapy in neonatal retinopathy of prematurity.

PURPOSE: To evaluate the relationships between optic nerve head blood flow, expressed as mean blur rate (MBR) measured by laser speckle flowgraphy (LSFG), and photocoagulation therapy in neonates with retinopathy of prematurity (ROP). STUDY DESIGN: Case series study. METHODS: We studied 5 ROP neonates either during sleep or under sedation both before and after photocoagulation, and evaluated 8 eyes in which the circulation could be measured three times consecutively. Correlations between the MBR-A (mean of all values), MBR-V (vessel mean) and MBR-T (tissue mean) and postmenstrual age were evaluated using Spearman's rank correlation coefficient. In addition, correlations between the relative MBR (-A, -V, -T) value and number of photocoagulation burns and the NV score were evaluated. Differences between post-treatment MBR in ROP subjects and normal neonates' MBR were estimated using analysis of covariance (ANCoVA), with adjustment for postmenstrual age. RESULTS: The relative MBR (-A, -V, -T) values after photocoagulation were 69.6 ± 16.0%, 66.7 ± 17.0% and 74.3 ± 14.6%, respectively. Postmenstrual age was significantly correlated with post-treatment MBR-A (r = 0.83, p = 0.0101), MBR-V (r = 0.85, p = 0.007) and MBR-T (r = 0.76, p = 0.0282). The relative MBR-T value was significantly correlated with the number of photocoagulation burns (r = -0.75, p = 0.033) and NV score (r = -0.72, p = 0.0437). The ANCoVA results showed no significant difference between post-treatment MBR and normal neonates' MBR. CONCLUSIONS: Photocoagulation improved the dilation of veins and tortuosity of arteries and reduced ocular blood flow in ROP subjects. Since the post-treatment MBR was not different from a normal neonate's MBR, it is suggested that the pre-treatment MBR was higher in severe ROP cases.