ASSOCIATION BETWEEN PLATELET INDICES AND RETINAL VEIN OCCLUSION: A Systematic Review and Meta-Analysis.

PURPOSE: Platelet count, mean platelet volume, platelet distribution width, and plateletcrit are standard indices of platelet activation that have been studied in retinal vein occlusion (RVO) and its subtypes: branch retinal vein occlusion and central retinal vein occlusion. This systematic review and meta-analysis aimed to assess the association between these platelet parameters and RVO. METHODS: We searched for studies investigating the association between these platelet indices and RVO in multiple online databases from inception to August 2020. Mean differences and the associated confidence intervals were obtained and calculated for each included study and pooled using random-effects inverse variance modeling. Meta-regression was used to explore interstudy and intrastudy heterogeneity. RESULTS: Thousand three hundred and twenty-five unique studies were screened, from which 24 studies encompassing 2,718 patients were included. Mean platelet volume and platelet distribution width were significantly elevated in RVO, with pooled mean differences of 0.45 fL (95% CI 0.24-0.66, P < 0.0001) and 1.43% (95% CI 0.57-2.29, P = 0.0011), respectively. Platelet count and plateletcrit were not significantly associated with RVO. Mean platelet volume was also independently elevated in branch retinal vein occlusion and central retinal vein occlusion. CONCLUSION: Mean platelet volume and platelet distribution width are significantly elevated in RVO. Further research is required to explore the independence and potential prognostic significance of these associations.

Effect of image averaging on optical coherence tomography angiography data in eyes with branch retinal vein occlusion.

PURPOSE: To investigate the effect of image averaging on qualitative and quantitative assessments of optical coherence tomography angiography (OCTA) images from eyes of patients with branch retinal vein occlusion (BRVO). METHODS: Macular OCTA images of 33 eyes of 33 patients with BRVO were obtained using the HS100 HR-SD-OCT system (Canon, Inc.). For each eye, five OCTA cube scans were obtained with a 3 × 3 mm scan protocol, and the data were averaged and compounded into a single high image quality cube data using built-in software. Pre- and post-averaging images were compared qualitatively and quantitatively in superficial capillary plexus (SCP) and deep capillary plexus (DCP) OCTA image slabs. RESULTS: After averaging, all OCTA images showed marked improvement in image quality with less background noise and better vessel continuity. The number of microaneurysms in both the SCP and DCP was larger in single images than in averaged images. A significant increase in the detection rate of capillary telangiectasia in the DCP was noted after image averaging. The number of eyes with disrupted foveal avascular zone (FAZ) decreased significantly after averaging (P = .0253). Five eyes (15.2%) with a disrupted FAZ on the single image showed an intact FAZ after averaging. Vessel length density (VLD) and fractal dimension (FD) significantly decreased and vessel diameter index (VDI) increased after averaging, while significant changes were not observed in vessel density (VD) in both the SCP and DCP. In the SCP, lower VD, VLD, and fractal dimension were significantly correlated with worse visual acuity. CONCLUSIONS: OCTA averaging has a significant effect on qualitative and quantitative assessments in eyes with BRVO.

Association of retinal venular tortuosity with impaired renal function in the Northern Ireland Cohort for the Longitudinal Study of Ageing.

BACKGROUND: Previous studies have identified retinal microvascular features associated with renal dysfunction. Biopsies are necessary to confirm kidney microvascular damage and retinal imaging may enable evaluation of microangiopathic characteristics reflecting renal changes associated with chronic kidney disease (CKD). We evaluated retinal microvascular parameters (RMPs) for associations with renal function in a cross-sectional analysis of the Northern Ireland Cohort for the Longitudinal Study of Ageing. METHODS: RMPs (central retinal arteriolar/ venular equivalents [CRAE/CRVE], arteriolar to venular ratio [AVR], fractal dimension and tortuosity) were measured from optic disc centred fundus images using semi-automated software. Associations were assessed with multivariable regression analyses between RMPs and estimated glomerular filtration rate (eGFR) defined by serum creatinine (eGFRscr) and cystatin C (eGFRcys) and also CKD status characterised by eGFR < 60 mL/min/1.73m2. Regression models were adjusted for potential confounders including age, sex, diabetes, smoking status, educational attainment, cardiovascular disease, body mass index, antihypertensive medication, systolic blood pressure, triglycerides, high- and low-density lipoprotein levels. RESULTS: Data were included for 1860 participants that had measures of renal function and retinal fundus images of sufficient quality for analysis. Participants had a mean age of 62.0 ± 8.5 yrs. and 53% were female. The mean eGFR for scr and cys were 82.2 ± 14.9 mL/min/1.73m2 and 70.7 ± 18.6 mL/min/1.73m2 respectively. eGFRcys provided lower estimates than eGFRscr resulting in a greater proportion of participants categorised as having CKD stages 3-5 (eGFRcys 26.8%; eGFRscr 7.9%). Multivariable regression analyses showed that increased venular tortuosity (OR = 1.30; 95%CI: 1.10, 1.54; P < 0.01) was associated with CKD stages 3-5 characterised by eGFRscr < 60 mL/min/1.73 m2. No additional associations between CKD status characterised by eGFRscr or with eGFRcys, were detected (P > 0.05). Multivariable regression failed to detect associations between CRAE, CRVE, AVR, fractal dimension or tortuosity and eGFRscr or eGFRcys (P > 0.05). CONCLUSION: Increased retinal venular tortuosity was associated with CKD stages 3-5 defined by eGFRscr < 60 mL/min/1.73 m2, in an older population independent of potential confounding factors. These retinal measures may provide non-invasive microvascular assessment of associations with CKD.

Comparison of Vessel Density Reduction in the Deep and Superficial Capillary Plexuses in Branch Retinal Vein Occlusion.

PURPOSE: To quantify the susceptibility of the deep capillary plexus (DCP) in comparison with that of the superficial capillary plexus (SCP) in eyes with branch retinal vein occlusion (BRVO) using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: SS-OCTA (TritonTM; Topcon, Tokyo, Japan) scans (3 × 3 mm) of 41 patients with BRVO were retrospectively analyzed. The mean vessel densities (VDs) of the SCP and the DCP were calculated in eyes with BRVO using the ImageJ program (National Institutes of Health, Bethesda, MD, USA) and compared with those in the normal fellow eye without any morbidity or unaffected sector in the BRVO eye. RESULTS: The reduction rate of mean VD in SCP and DCP between the affected and unaffected sector of eyes with BRVO was 13.88 and 24.60%, respectively. Additionally, the reduction rate of mean VD in the SCP and DCP in the affected sector of BRVO eyes versus the corresponding sector of fellow eyes was 13.31 and 24.49%, respectively. CONCLUSION: The DCP was 1.77-1.84 times more affected than the SCP by ischemic damage in eyes with BRVO.

Retinal Vasculometry Associations with Cardiometabolic Risk Factors in the European Prospective Investigation of Cancer-Norfolk Study.

PURPOSE: To examine associations between retinal vessel morphometry and cardiometabolic risk factors in older British men and women. DESIGN: Retinal imaging examination as part of the European Prospective Investigation into Cancer-Norfolk Eye Study. PARTICIPANTS: Retinal imaging and clinical assessments were carried out in 7411 participants. Retinal images were analyzed using a fully automated validated computerized system that provides novel measures of vessel morphometry. METHODS: Associations between cardiometabolic risk factors, chronic disease, and retinal markers were analyzed using multilevel linear regression, adjusted for age, gender, and within-person clustering, to provide percentage differences in tortuosity and absolute differences in width. MAIN OUTCOMES MEASURES: Retinal arteriolar and venular tortuosity and width. RESULTS: In all, 279 802 arterioles and 285 791 venules from 5947 participants (mean age, 67.6 years; standard deviation [SD], 7.6 years; 57% female) were analyzed. Increased venular tortuosity was associated with higher body mass index (BMI; 2.5%; 95% confidence interval [CI], 1.7%-3.3% per 5 kg/m2), hemoglobin A1c (HbA1c) level (2.2%; 95% CI, 1.0%-3.5% per 1%), and prevalent type 2 diabetes (6.5%; 95% CI, 2.8%-10.4%); wider venules were associated with older age (2.6 µm; 95% CI, 2.2-2.9 µm per decade), higher triglyceride levels (0.6 µm; 95% CI, 0.3-0.9 µm per 1 mmol/l), BMI (0.7 µm; 95% CI, 0.4-1.0 per 5 kg/m2), HbA1c level (0.4 µm; 95% CI, -0.1 to 0.9 per 1%), and being a current smoker (3.0 µm; 95% CI, 1.7-4.3 µm); smoking also was associated with wider arterioles (2.1 µm; 95% CI, 1.3-2.9 µm). Thinner venules were associated with high-density lipoprotein (HDL) (1.4 µm; 95% CI, 0.7-2.2 per 1 mmol/l). Arteriolar tortuosity increased with age (5.4%; 95% CI, 3.8%-7.1% per decade), higher systolic blood pressure (1.2%; 95% CI, 0.5%-1.9% per 10 mmHg), in females (3.8%; 95% CI, 1.4%-6.4%), and in those with prevalent stroke (8.3%; 95% CI, -0.6% to 18%); no association was observed with prevalent myocardial infarction. Narrower arterioles were associated with age (0.8 µm; 95% CI, 0.6-1.0 µm per decade), higher systolic blood pressure (0.5 µm; 95% CI, 0.4-0.6 µm per 10 mmHg), total cholesterol level (0.2 µm; 95% CI, 0.0-0.3 µm per 1 mmol/l), and HDL (1.2 µm; 95% CI, 0.7-1.6 µm per 1 mmol/l). CONCLUSIONS: Metabolic risk factors showed a graded association with both tortuosity and width of retinal venules, even among people without clinical diabetes, whereas atherosclerotic risk factors correlated more closely with arteriolar width, even excluding those with hypertension and cardiovascular disease. These noninvasive microvasculature measures should be evaluated further as predictors of future cardiometabolic disease.

Venous thrombosis in unusual sites: A practical review for the hematologist.

Thrombosis of unusual venous sites encompasses a large part of consultative hematology and is encountered routinely by practicing hematologists. Contrary to the more commonly encountered lower extremity venous thrombosis and common cardiovascular disorders, the various thromboses outlined in this review have unique presentations, pathophysiology, workup, and treatments that all hematologists should be aware of. This review attempts to outline the most up to date literature on cerebral, retinal, upper extremity, hepatic, portal, splenic, mesenteric, and renal vein thrombosis, focusing on the incidence, pathophysiology, provoking factors, and current recommended treatments for each type of unusual thrombosis to provide a useful and practical review for the hematologist.

Longitudinal vasculature changes in branch retinal vein occlusion with projection-resolved optical coherence tomography angiography.

PURPOSE: To analyze vascular changes in branch retinal vein occlusion (BRVO) using projection-resolved optical coherence tomography angiography (PR-OCTA). METHODS: We reviewed 30 consecutive eyes of 30 cases with BRVO retrospectively. PR-OCTA was performed during the acute, intermediate, and remission phases when anti-vascular endothelial growth factor drugs suppress cystic changes. The main outcome measures were vessel density (VD) and retinal thickness changes in the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP). RESULTS: The VDs did not change longitudinally in the SCP and DCP during the follow-up period. The VD was significantly (p = 0.0105) greater in the ICP during remission than the acute phase. The full retinal thickness (internal limiting membrane [ILM] to retinal pigment epithelium [RPE]) and inner retinal thickness (ILM to inner plexiform layer [IPL]) decreased significantly (p = 0.0002 and p = 0.0014, respectively) during the follow-up period. When the inner retina was thinner than 117 µm, the VD in the ICP increased significantly (p = 0.045) during the follow-up period. When the inner retinal layer did not become thinner, the VD in the ICP remained unchanged. CONCLUSION: PR-OCTA showed the three distinct vascular plexuses in BRVO. The VDs remained unchanged during the follow-up period in the SCP and DCP but increased significantly in the ICP during remission. Inner retinal thinning might cause increases in the VD in the ICP because of projection artifacts and segmentation errors despite using PR-OCTA.

USE OF THE ISCHEMIC INDEX ON WIDEFIELD FLUORESCEIN ANGIOGRAPHY TO CHARACTERIZE A CENTRAL RETINAL VEIN OCCLUSION AS ISCHEMIC OR NONISCHEMIC.

PURPOSE: To understand the relationship between baseline ischemic index (IsI) values on ultra-widefield fluorescein angiography and classification as ischemic central retinal vein occlusion (CRVO). METHODS: Single-center retrospective cohort study of CRVO patients imaged using ultra-widefield fluorescein angiography from which IsI values were calculated. An ischemic CRVO was defined as those eyes with an afferent pupillary defect and counting fingers acuity or worse or neovascularization during the first year of follow-up. Logistic regression was performed to characterize the relation between the IsI and clinical outcomes. RESULTS: Sixty eyes of 60 treatment-naive CRVO patients with baseline ultra-widefield fluorescein angiography and ≥1 year of follow-up were identified. Those with an IsI ≥35% were significantly more likely to have an ischemic CRVO during the first year of follow-up than those with an IsI <35% (83.3 vs. 13.9%, odds ratio 111, P < 0.0001). Baseline and final logarithm of the minimum angle of resolution acuity were worse in eyes with an IsI ≥35% (1.18 vs. 0.46, P < 0.001 and 1.26 vs. 0.45, P < 0.001, respectively) despite similar baseline and final central subfield thickness (P = 0.1-0.23). CONCLUSION: A baseline IsI of ≥35% on ultra-widefield fluorescein angiography in eyes with treatment-naive CRVO was sensitive (90%) and specific (92.5%) for classification as an ischemic CRVO during the first year of follow-up.

Hand and knee osteoarthritis are associated with reduced diameters in retinal vessels: the AGES-Reykjavik study.

To investigate the association between osteoarthritis (OA) and microvascular pathology, we examined the relationship between retinal microvascular caliber and osteoarthritis of the hand and knee in an elderly population. The AGES-Reykjavik is a population-based, multidisciplinary longitudinal cohort study of aging. Retinal vessel caliber, hand osteoarthritis and total knee joint replacements due to OA were examined in 4757 individuals (mean age 76 ± 5 years; 57% female). Incident knee joint replacements during 5-year follow-up (n = 2961, mean age 75 ± 5 years; 58% female) were also assessed. Logistic regression analysis, adjusting for age, sex, and body mass index, showed an association between narrow arteriolar caliber and hand OA, as well as knee replacement. After adjustment for other covariates, including statin therapy, this association was significant for both hand OA in men and women [OR 1.10(1.03-1.17), p < 0.01] (per unit standard deviation decrease in CRAE) and TKR prevalence [OR 1.15 (1.01-1.32), p = 0.04], especially for men [OR 1.22 (1.00-1.51) p = 0.04] and also for incident TKRs in men [OR 1.50 (1.07-2.10), p = 0.04]. Narrow venular caliber was associated with hand OA in women [OR 1.10 (1.01-1.21), p = 0.03]. Retinal arterial narrowing in hand and knee OA is present in males as well as females. Venular narrowing in hand OA in women was an unexpected finding and is in contrast with the venular widening usually observed in cardiovascular diseases.

Abnormal retinal microvasculature found in active rheumatoid arthritis:a different perspective of microvascular health

Background/aim: We aimed to assess the association between retinal vascular caliber (RVC) scores and disease activity in rheumatoid arthritis (RA) patients. Materials and methods: Forty-seven RA patients, 32 systemic lupus erythematosus (SLE) patients, and 45 healthy people were enrolled. RA and SLE patients were subdivided into groups according to C-reactive protein (CRP) levels. RA patients were also grouped according to Disease Activity Score-28 (DAS-28). Fundus photography was performed for all patients. RVC was summarized as the central retinal artery and vein equivalents (CRAE and CRVE). Results: Mean CRVE for RA patients was 213.3 ± 17.8 µm compared with 209.2 ± 14.1 µm for SLE and 217.5 ± 26.2 µm for the control group (P = 0.17). RVC scores did not differ between the CRP-high and CRP-low groups. As the RA disease activity increased, the widening of CRVE became more prominent and statistically significant. When the DAS-28 > 5.1 (CRVE, 220.4 (211.8­246.5) µm) group and DAS-28 ≤ 3.2 (CRVE, 214.4 (172.4­242.3) µm) group were compared, statistical significance was more pronounced (P = 0.03) than when comparing the DAS-28 > 3.2 and DAS-28 ≤ 3.2 groups (P = 0.05). Conclusions: CRVE, which reflects systemic inflammation and possibly increased cardiovascular risk, was significantly increased in active RA patients. The association between retinal venular widening and disease activity, regardless of CRP, may be a sign that RA-related inflammation may have systemic vascular effects even with normal levels of CRP.

Venous beading in two or more quadrants might not be a sensitive grading criterion for severe nonproliferative diabetic retinopathy.

PURPOSE: To determine whether venous beading (VB) in two or more quadrants is an appropriate grading criterion for severe nonproliferative diabetic retinopathy (NPDR). METHODS: A hospital-based, retrospective, cross-sectional study. A total of 806 patients admitted with diabetic retinopathy (DR) from January 2014 to April 2017 were included in this study. DR severity was graded by the international grading criterion. The status of VB, intraretinal microvascular abnormalities (IRMA), capillary nonperfusion, arteriovenous nicking, and diabetic macular edema was evaluated based on fundus fluorescein angiography. RESULTS: The prevalence of VB in eyes with proliferative diabetic retinopathy (PDR), severe NPDR, and moderate NPDR was 41.3% (327/791), 5.9% (31/526), and 0% (0/295), respectively (p < 0.001). Moreover, the proportion of VB in two or more quadrants was even lower (27.1% for PDR and 2.1% for severe NPDR, p < 0.001), and among the total of 225 eyes with VB in two or more quadrants, 214 eyes (95.1%) were graded as PDR. Furthermore, VB formation was significantly correlated with capillary nonperfusion, duration of diabetes (both p < 0.001), and smoking (p < 0.05). After adjusting for age, sex, and other possible factors, VB (OR = 7.479, p < 0.001) and IRMA (OR = 2.433, p < 0.001) were determined as independent risk factors for developing PDR. CONCLUSIONS: Our study suggested that VB in two or more quadrants might not be a sensitive grading criterion for severe NPDR among a Chinese population with type 2 diabetes. Nevertheless, VB has a great specificity to define an advanced form of DR.

EFFECTS OF INTRAVITREAL RANIBIZUMAB AND BEVACIZUMAB ON THE RETINAL VESSEL SIZE IN DIABETIC MACULAR EDEMA.

PURPOSE: The goal of this study was to assess the effects of a single injection of intravitreal ranibizumab (RAN) or bevacizumab (BEV) on the retinal vessel size in eyes with diabetic macular edema. MATERIALS AND METHODS: In total, 32 patients were enrolled in the RAN group, and 30 patients were included in BEV group. Each of these groups was also subdivided into two others groups: a study group and a control group. The study groups were composed of the injected eyes, whereas the noninjected fellow eyes served as the control groups. The patients underwent complete ophthalmic examinations, including optical coherence tomography and fundus fluorescein angiography, and the primary outcome measures included the central retinal artery equivalent, central retinal vein equivalent, and artery-to-vein ratio. RESULTS: In the RAN study group (n = 32), the preinjection mean central retinal artery equivalent (175.42 µm) decreased to 169.01 µm after 1 week, and to 167.47 µm after 1 month (P < 0.001), whereas the baseline central retinal vein equivalent (235.29 µm) decreased initially to 219.90 µm after 1 week, and to 218.36 µm after 1 month (P < 0.001). In the BEV study group (n = 30), the preinjection central retinal artery equivalent (150.21 µm) decreased to 146.25 µm after 1 week, and to 145.89 µm after 1 month (P < 0.001); whereas the baseline central retinal vein equivalent (211.87 µm) decreased initially to 204.59 µm after 1 week and was 205.24 µm after 1 month (P < 0.001). The preinjection artery-to-vein ratio values changed significantly (P = 0.001) after 1 week and after 1 month in the RAN group, but no significant alteration in the artery-to-vein ratio was observed in the BEV group (P = 0.433). In both the RAN (n = 32) and BEV (n = 30) control groups, none of the 3 parameters changed throughout the study period, when compared with the baseline. CONCLUSION: The results of this study showed that both RAN and BEV injections significantly constricted the retinal blood vessel diameters.

Pigmented paravenous retinochoroidal atrophy: a case report.

BACKGROUND: Pigmented paravenous retinochoroidal atrophy (PPRCA) is an unusual retinal degeneration, and its performance on optical coherence tomography angiography (OCTA) is unclear. We report a Chinese female case of PPRCA and her OCTA features. CASE PRESENTATION: A 66-year-old female patient was referred to the author's center for gradual progressive loss of vision in both eyes and photophobia of 2 years duration. She reported having no family history of inherited ocular diseases. The funduscopic examination revealed bone-spicule pigmentation and retinochoroidal atrophy along the retinal veins. This patient was diagnosed with PPRCA which is a rare disease, uncommon in females, more commonly affecting the paravascular fundus. Noninvasive imaging techniques features of this patient was described, including ultra-wide field fundus autofluorescence, spectral domain optical coherence tomography (SD-OCT), OCTA (SSADA), etc. The en face OCTA images demonstrated areas of flow void beneath the retinal pigment epithelium-Bruch membrane layer suggestive of choriocapillaris hypoperfusion that corresponded with indocyanine green angiography (ICGA). Further studies should be conducted to clarify the relationship between choriocapillaris hypoperfusion and the development of PPRCA. CONCLUSIONS: The OCTA features in patients with PPRCA has not been described previously in the literature. This case might provide preliminary information regarding the pathophysiology of PPRCA and improve our understanding of the nature of this disease.

Optical coherence tomography angiography wide-field montage in branch retinal vein occlusion before and after anti-vascular endothelial-derived growth factor injection.

The wide-field montage technique of optical coherence tomography angiography provides good delineation of the improvement in microvascular disturbance associated with branch retinal vein occlusion after treatment with anti-vascular endothelial-derived growth factor injection. It may be further evaluated for the assessment of treatment progress in patients with retinal vein occlusion.

Effect of oral niacin on central retinal vein occlusion.

PURPOSE: Niacin, a treatment for dyslipidemia, is known to induce vasodilation as a secondary effect. Previous instances of patients with chronic central retinal vein occlusion (CRVO) and cystoid macular edema (CME) have been observed to spontaneously improve when placed on systemic niacin for hypercholesterolemia. The purpose of this study was to evaluate the effects of niacin on CRVO and associated ocular complications. METHODS: A prospective, single-center, non-randomized, interventional case series of niacin for CRVO was conducted. Best-correct visual acuity (BCVA), central macular thickness (CMT), and ocular complications were analyzed in 50 patients over 1 year. Eight patients were controls. RESULTS: The mean initial logMAR BCVA was 0.915, and improved with niacin to 0.745 (P = 0.12), 0.665 (P = 0.02) and 0.658 (P = 0.03) after 3, 6, and 12 months of follow-up, respectively. At baseline, mean CMT was 678.9 µm, and improved to 478.1 µm (P = 0.001), 388.6 µm (P < 0.001), and 317.4 µm (P < 0.001) for the same time points. The control group had a mean initial logMAR BCVA of 1.023, which gradually deteriorated to 1.162 (P = 0.36) after 12 months, and baseline CMT of 700.0 µm at baseline, which gradually improved to 490.9 µm (P = 0.06) after 12 months. Panretinal photocoagulation for neovascularization was required in 5 patients (13.2%) receiving niacin and 3 (37.5%) controls. CONCLUSIONS: These data suggest that niacin may be associated with functional and anatomic improvements in eyes with CRVO. Future investigations will help ascertain whether there is a role for niacin as an adjunct therapy to intravitreal injections in the management of CRVO.

DYNAMIC AND STATIC VESSEL ANALYSIS IN PATIENTS WITH RETINITIS PIGMENTOSA: A Pilot Study of Vascular Diameters and Functionality.

PURPOSE: To evaluate in vivo the vascular anatomy and functionality of early manifestation retinitis pigmentosa (RP) by means of a dynamic and static vessel analyzer. METHODS: Fourteen patients with early RP and 14 normal subjects were consecutively enrolled in this observational, prospective study. Each patient underwent a complete ophthalmologic examination, including dynamic and static retinal vessel analysis using the Dynamic Vessel Analyzer. RESULTS: The patients with RP and the control group were well matched in age and sex. Patients with RP had a mean best-corrected visual acuity of 20/25 (range: 20/40-20/20). Dynamic vessel analysis performed in patients with RP showed an arterial and venous dilation during flicker stimulation of 5.28 ± 1.7% and 4.07 ± 1.78%, respectively. Only arterial dilation was statistically different compared with control subjects (3.33 ± 0.99%, P = 0.0062). Static retinal vessel analysis in patients with RP showed a decreased mean central retinal artery equivalent (P < 0.001) and central retinal vein equivalent (P < 0.001) compared with control subjects. By contrast, the arterial-to-venous ratio was similar in both groups (RP: 0.79 ± 0.11, control group 0.86 ± 0.04, P = 0.072). CONCLUSION: Our data confirm that retinal arterial and venous narrowing is present at an early stage in patients affected by RP. However, dynamic vessel analysis shows how the retina of patients with RP with no best-corrected visual acuity loss presents an augmented artery dilation response compared with normal subjects and retained neurovascular coupling.

QUALITATIVE AND QUANTITATIVE FOLLOW-UP USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF RETINAL VEIN OCCLUSION TREATED WITH ANTI-VEGF: Optical Coherence Tomography Angiography Follow-up of Retinal Vein Occlusion.

PURPOSE: To evaluate changes of vascular flow of patients treated with intravitreal injections of anti-vascular endothelial growth factor for macular edema secondary to retinal vein occlusion (RVO) with optical coherence tomography angiography (OCTA). METHODS: Patients with RVO with macular edema and treated with intravitreal injections of anti-vascular endothelial growth factors were retrospectively evaluated. The following examinations were performed before and after treatment: best-corrected visual acuity, spectral domain optical coherence tomography, fluorescein angiography, and OCTA (Optovue, Inc). Automatic measurement of vascular density of the superficial and deep capillary plexus was also performed and compared with age- and sex-matched healthy subjects. RESULTS: Twenty-eight eyes of 28 patients (mean age 66.2 years; males 19%) were evaluated, including 13 central RVO, 11 branch RVO, and 4 hemicentral RVO. After treatment, mean central macular thickness significantly decreased from 644 µm to 326 µm and best-corrected visual acuity increased from 20/125 to 20/63 (P < 0.01 for both results). On OCTA, perifoveal capillary disruption (P = 0.029) and the number of cysts in the superficial capillary plexus and deep capillary plexus (P < 0.002) significantly decreased after treatment. The mean vascular density in the superficial capillary plexus slightly decreased during follow-up from 46.44% to 45.01% (not significantly). These densities were significantly less than those observed in healthy controls (P < 0.001). CONCLUSION: Optical coherence tomography angiography showed regression of macular edema, reduced capillary disruption and cysts, and slight decrease in mean macular vascular density with time and despite treatment. Thus, OCTA enables qualitative and quantitative evaluation during follow-up of patients treated for RVO.

Relationship of retinal vascular caliber variation with intracranial arterial stenosis.

BACKGROUND & PURPOSE: To investigate the associations of retinal vessel parameters with intracranial arterial stenosis (ICAS) assessed by Transcranial Doppler ultrasonography. METHOD: Data on transcranial Doppler ultrasonography and quantitative retinal vessel parameters from 627 participants in a health screening program were included in this study. ICAS was defined as >50% intracranial arterial stenosis (ICAS) based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis (SONIA) trial assessed by transcranial Doppler (TCD) ultrasonography. A semi-automated computer-assisted program (Singapore I Vessel Assessment) was used to measure the retinal vascular parameters from the photographs. Multivariate analysis was performed to identify which retinal vessel parameters were associated with increased risk of ICAS. RESULTS: Among 627 participants, 24 (3.8%) had ICAS diagnosed by TCD. Subjects with ICAS had eyes with wider mean central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) in comparison to subjects without ICAS. Men (odds ratio [OR]:13.1, 95% confidence interval: 3.13-33.33) and a large standard deviation of mean arterial width (STDWa) were associated with ICAS (first vs. third tertile: OR ratio: 14.04, 95% confidence interval: 1.71-115.32; first vs. third tertile: OR ratio: 22.1, 95% confidence interval: 2.56-190.97) after adjusting for possible confounders. CONCLUSION: A large variation in retinal arteriolar diameter is associated with ICAS. This study suggests the possible relationship between retina vessel and early changes within the cerebrovascular network.

WIDEFIELD FLUORESCEIN ANGIOGRAPHY IN PATIENTS WITHOUT PERIPHERAL DISEASE: A Study of Normal Peripheral Findings.

PURPOSE: Widefield photography and angiography provide access up to 200-degrees of the retinal periphery. The range of normal peripheral findings has not been characterized, yet is relevant to studies addressing putative peripheral retinal vascular pathology. METHODS: This study was an observational retrospective cohort study. Adult patients with epiretinal membrane or choroidal nevi who underwent imaging with Optos 200 MA/200Tx were included. Dye transit times, peripheral arteriovenous shunting, presence of vessels crossing the horizontal raphe, right angle vessels, terminal networks, absence of capillary detail, ground glass hyperfluorescence, peripheral drusen, and microaneurysms were evaluated. RESULTS: Fifty-eight eyes of 31 patients met inclusion criteria. Mean peripheral arterial filling time was 8.65 ± 2.54 seconds (range 3-15 seconds). One or more peripheral anomalies were noted in all patients (P < 0.01). The prevalences of findings were: arteriovenous shunting (0.00%), vessels crossing the horizontal raphe (44.83%), right angle vessels (70.69%), terminal networks (77.59%), absence of capillary detail (98.28%), ground glass hyperfluorescence (87.93%), drusen (34.48%), and microaneurysms (41.38%). CONCLUSION: There was a high prevalence of peripheral vascular anatomic variations in eyes expected to have normal peripheral retinal vasculature. These findings may provide a reference for future studies addressing putative pathologic peripheral angiographic findings.