Alterations in retinal and choroidal thickness following nonarteritic anterior ischemic optic neuropathy.

PURPOSE: To show alterations of retinal arteriolar caliber (RAC), retinal venular caliber (RVC), retinal nerve fiber layer thickness (RNFLT), peripapillary choroidal thickness (ppCT), and central macular thickness (CMT) in acute and chronic phases of nonarteritic anterior ischemic optic neuropathy (NAION). METHODS: Forty-one eyes of 41 patients with NAION were included in this retrospective study. RAC, RVC, RNFLT, ppCT, and CMT measurements were performed via spectral-domain optical coherence tomography in the acute and chronic phases of NAION. RESULTS: RVC, RNFLT, ppCT, and CMT were significantly thinner in the chronic phase compared to the acute phase (p < 0.001), whereas RAC remained similar throughout the visits (p = 0.26). The visual acuity difference between the acute and chronic phases was not correlated with the changes of RAC, RVC, RNFLT, ppCT, or CMT. CONCLUSIONS: RVC, RNFLT, ppCT, and CMT decreases in the chronic phase when compared to the acute phase of NAION, whereas RAC does not change significantly.

Association of dietary nitrate intake with retinal microvascular structure in older adults.

PURPOSE: Existing research suggests that changes to retinal vascular caliber reflect nitric oxide (NO)-dependent endothelial dysfunction. Dietary nitrate is an important source of NO; however, studies on the link between dietary nitrate intake and retinal microvasculature are lacking. We aimed to assess the cross-sectional association between intake of dietary nitrate (from vegetable and non-vegetable sources) and retinal arteriolar and venular caliber among older adults. METHODS: Participants from the Blue Mountains Eye Study aged 49+ years with complete data at baseline on diet and retinal vessel measures were analyzed (n = 2813). Dietary intake was assessed using a validated semi-quantitative food-frequency questionnaire. Nitrate intake from vegetable and non-vegetable sources was estimated using a validated comprehensive database and other published data where necessary. Fundus photographs were taken and retinal vascular caliber measured using validated computer-assisted techniques and summarized. RESULTS: Participants in the lowest versus highest tertile of vegetable nitrate intake had significantly narrower retinal arterioles: 186.2 ± 0.48 versus 187.6 ± 0.48 µm (multivariable-adjusted p = 0.04). After multivariable adjustment, each 10-unit higher intake of total nitrate and vegetable nitrate was associated with 0.089 ± 0.004 and 0.090 ± 0.004 µm wider retinal arteriolar caliber, respectively, both p = 0.03. Each 10-unit higher vegetable nitrate intake was associated with 0.092 ± 0.005 µm narrower retinal venules (p = 0.05). CONCLUSION: Intake of dietary nitrate, particularly from vegetable sources, was associated with beneficial variations in both retinal arteriolar and venular caliber among older adults. Further research into associations between dietary nitrate and the retinal microvasculature could allow for greater understanding and possible prevention of clinical cardiovascular events.

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.

Retinal vascular diameters in relation to physical activity in Danish children - The CHAMPS Eye Study.

Our objective was to determine associations between retinal vascular caliber and physical activity (PA) in a school-based child cohort. In a prospective study, we created a childhood cumulative average PA-index using objectively measured PA (accelerometry) assessed at four periods between 2009 and 2015. Cumulative exposure to PA intensities was estimated. Cross-sectional examinations on biomarkers, anthropometry, and ophthalmological data including retinal fundus photographs were performed in 2015. Semi-automated measurements of retinal vascular diameters were performed and summarized into central retinal arteriolar and venular equivalents (CRAE, CRVE). We included 307 participants. Mean age in 2015 was 15.4 years (0.7). The mean CRAE and CRVE were 156.5 µm (2.8) and 217.6 µm (7.7), respectively. After adjusting for age, gender, and axial length, more time in PA was independently related to thinner retinal venules (ß-coefficient = -1.25 µm/%, 95% confidence interval = -2.20, -0.30, P < .01). Sedentary time was associated with wider venules (P < .01). Furthermore, birthweight (ß-coefficient = 0.56 µm/%, 95% confidence interval = 0.18, 0.95, P < .01) was associated with CRVE. Blood pressure was associated with thinner retinal arterioles (ß-coefficient = -0.19 µm/mmHg, 95% confidence interval = -0.36, -0.01, P = .04). We concluded that children with higher PA in childhood had thinner retinal venular caliber. Our results suggest that PA during childhood positively impacts the retinal microcirculation and that retinal vascular analysis may be a possible assessment to detect microvascular impairments in children with an increased risk of future cardiovascular disease.

Sleep apnea and retinal signs in cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis.

PURPOSE: The aim of the study was to examine the relationship between sleep apnea, retinal vascular caliber and retinopathy, and their impact on cardiovascular disease (CVD) risk. METHODS: A multi-ethnic cohort of 5,803 participants was examined based on standardized grading of retinal vascular caliber and retinopathy from digital fundus photographs, self-reported physician-diagnosed sleep apnea (PDSA), and incident cardiovascular events. RESULTS: In women, PDSA was associated with narrower arterioles (regression coefficient [ß] -5.76; 95 % confidence Interval [CI] -8.51, -3.02) after adjusting for cardio-metabolic risk factors. The incident rate ratio (IRR) of CVD was also associated with narrower arterioles (IRR for highest versus lowest tertile 1.91; 95 % CI 1.08, 3.38). In men, PDSA was not associated with arteriolar caliber. However, incident CVD was associated with narrower arterioles (IRR 1.67; 95 % CI 1.10, 2.52), wider venules (IRR 1.71; 95 % CI 1.13, 2.59) and PDSA (IRR 2.03, 95 % CI 1.17, 3.51). The IRR of CVD in men with PDSA increased minimally to 2.06 (95 % CI 1.18, 3.56) after adjustment for retinal arteriolar and venular caliber. Combining women and men, the IRR of CVD was 3.41 (95 % CI 1.79, 6.50) in those with both PDSA and narrower retinal arterioles. CONCLUSIONS: Sleep apnea was associated with narrower retinal arterioles in women but not in men. However, sleep apnea was also associated with incident CVD in men. These suggest potential gender differences in susceptibility to microvascular disease in association with sleep apnea.

Reduced cranial parasympathetic tone during the remission phase of cluster headache.

BACKGROUND: Cluster headache (CH) attacks are accompanied by cranial autonomic symptoms indicative of parasympathetic hyperactivity and sympathetic dysfunction ipsilateral to the pain. We aimed to assess cranial autonomic function in CH patients during the remission phase of cluster headache. MATERIALS AND METHODS: During a remission phase, 38 episodic CH patients underwent the following: dynamic pupillometry, measurement of the superficial temporal artery diameter by ultrasound, and measurement of the retinal vessel diameters from digital retinal photographs. Pupillometry was also performed on 30 age- and sex-matched healthy controls. RESULTS: Thirty patients were included (27 men, three women, mean age 50.2 years ± 12.6). Seven patients reported occasional side shift of their headache, but with a clear predominating side. Significantly reduced average pupillary constriction velocity and retinal venular diameter on the CH pain side were found. There was no asymmetry of the superficial temporal artery diameters. Compared to healthy controls, cluster patients displayed bilaterally reduced pupillary average and maximum constriction velocities, reduced constriction in percentage and increased latency of the light reflex. CONCLUSIONS: The present findings indicate a bilaterally reduced cranial parasympathetic tone in CH patients in remission phase, with significant lateralization to the CH pain side. This implies a central origin, and a central pathophysiological model of CH is discussed.

Effects of coronary artery bypass grafting surgery on retinal vascular caliber, ocular pulse amplitude and retinal thickness measurements.

AIM: The retina and ocular vasculature are vulnerable to alterations in systemic hemodynamics, such as in open heart surgeries. Our aim was to investigate retinal vascular caliber (RVC), ocular pulse amplitude (OPA), peripapillary retinal nerve fiber layer (RNFL) and macular thickness in coronary artery bypass grafting (CABG) surgery patients. METHODS: Twenty-six patients who had a history of CABG surgery and 26 age-sex-matched healthy participants were recruited for this prospective, cross-sectional and comparative study. The RVC, peripapillary RNFL and macular thickness measurements were taken with spectral-domain optical coherence tomography. The OPA, a surrogate of pulsatile ocular blood flow, was measured with the Pascal dynamic contour tonometer. RESULTS: There were no statistically significant differences between the CABG surgery patients and the controls with regard to RVC, OPA, peripapillary RNFL thickness and macular thickness measurements (p>0.05). CONCLUSIONS: CABG surgery does not affect retinal structures and pulsatile ocular blood flow in the long-term follow-up.

Choroidal thickness and retinal vascular caliber correlations with internal carotid artery Doppler variables.

PURPOSE: Decreased retinal arteriolar caliber and increased retinal venular caliber have been associated with increased cardiovascular mortality. This study aimed to evaluate correlations of choroidal thickness and retinal vascular caliber measurements with internal carotid artery (ICA) Doppler ultrasound variables. METHODS: In this cross-sectional and observational study, 43 eyes and ICAs of 43 healthy volunteers were examined. Spectral domain optical coherence tomography was used to measure subfoveal choroidal thickness (SFCT) and retinal vascular caliber. The ICA Doppler ultrasonographic parameters were diameter, flow volume, peak-systolic velocity, end-diastolic velocity, resistance index (RI), and pulsatility index (PI). RESULTS: Negative correlations emerged between ICA RI and SFCT (p = 0.017, r = -0.36) as well as between ICA PI and retinal arteriolar caliber (p = 0.015, r = -0.37). A negative linear correlation appeared between ICA diameter and SFCT (p = 0.005, r = -0.42), although ICA diameter and flow volume showed no association with retinal vessel caliber (p > 0.05). CONCLUSIONS: Choroidal thickness is negatively correlated with ICA diameter and ICA RI, while retinal arteriolar caliber is inversely related with ICA PI in normal volunteers.

Lower dairy products and calcium intake is associated with adverse retinal vascular changes in older adults.

BACKGROUND AND AIMS: Higher consumption of dairy products and calcium is likely to play a role in maintaining optimal vascular health. In this study, we aimed to explore the associations between consumption of total-, regular- and low-fat dairy foods, and total calcium intake with retinal vascular caliber. METHODS AND RESULTS: 2813 Blue Mountains Eye Study participants aged 50+ years had dietary data collected using a semi-quantitative food frequency questionnaire, and serves of dairy consumption were calculated. Fundus photographs were taken and retinal vascular caliber measured using computer-assisted techniques and summarized. After adjusting for age, sex, body mass index, smoking, mean arterial blood pressure, serum glucose, white cell count, history of diagnosed hypertension, stroke and coronary heart disease, plus retinal arteriolar caliber, participants in the lowest quintile of total dairy consumption compared to those in the remaining highest 4 quintiles had significantly wider retinal venular caliber, 227.2 versus 224.7 µm, respectively (multivariable-adjusted p = 0.002). Also, subjects in the lowest quintile of low-fat dairy product consumption versus those in the remaining quintiles of low-fat dairy intake had wider retinal venules (∼ 1.7 µm, p = 0.03) and narrower retinal arterioles (∼ 1.4 µm, p = 0.04). Participants in the lowest quintile versus highest quintile of total dietary calcium intake had ∼ 2.3 µm wider retinal venules (multivariable-adjusted p-trend = 0.02). CONCLUSIONS: A significant association was observed between lower intake of dairy products or calcium and adverse retinal vascular signs. We cannot discount the possibility of confounding from unmeasured risk factors; hence, further studies are warranted to confirm these findings.

Dietary Vitamins A, C, and Potassium Intake Is Associated With Narrower Retinal Venular Caliber.

INTRODUCTION: The retinal vasculature, a surrogate for the systemic microvasculature, can be observed non-invasively, providing an opportunity to examine the effects of modifiable factors, such as nutrient intake, on microcirculation. We aimed to investigate the possible associations of dietary nutrient intake with the retinal vessel caliber. METHODS: In this cross-sectional study, a total of 584 participants in a medical survey of Japanese descendants living in Los Angeles in 2015 underwent a dietary assessment, fundus photographic examination, and comprehensive physical and blood examinations. Retinal vessel caliber was measured using fundus photographs with a semi-automated computer system and summarized as central retinal artery and vein equivalents (CRAE and CRVE). The association between dietary nutrient intake and retinal vessel caliber was analyzed using a multivariate linear regression model adjusted for two models including potential confounders. The first model was adjusted for age and sex. The second model was adjusted for age, sex, smoking status, body mass index, hypertension, diabetes, dyslipidemia, history of coronary heart disease, and history of stroke. RESULTS: After adjustment of potential confounders, compared to the quartile with the lowest intake, the difference in CRVE for the highest quartile was -5.33 µm [95% confidence interval (CI): -9.91 to -0.76, P for trend = 0.02] for vitamin A, -4.93 µm (95% CI: -9.54 to -0.32, P for trend = 0.02) for vitamin C and -3.90 µm (95% CI: -8.48 to 0.69, P for trend = 0.04) for potassium. CONCLUSIONS: A significant association was observed between higher vitamins A, C and potassium intakes and narrower retinal venular caliber.

Retinal vascular caliber in patients with newly diagnosed iron deficiency anemia.

BACKGROUND: To evaluate the retinal vascular caliber using fundus photography in patients with newly diagnosed iron deficiency anemia (IDA). METHODS: This study included 56 eyes of 28 female patients with IDA and the 56 eyes of 28 age- and sex-matched healthy participants. Retinal vascular calibers were measured using image analysis software from fundus photographs. The central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE) and arteriole-to-venule ratio (AVR) were compared between groups. Linear regression analysis was used to quantify the relative impact of hemoglobin level on CRAE, CRVE, and AVR. RESULTS: The CRAE was significantly narrower in patients with IDA. However, no such difference appeared between groups in CRVE. AVR was significantly lower among patients with IDA than in the control group. Linear regression analysis revealed that in patients with IDA, hemoglobin level was associated with CRAE and CRVE but not with AVR. Among non-anemic individuals, there was also no association between hemoglobin level and CRAE, CRVE, or AVR. CONCLUSIONS: Our results showing that the CRAE is significantly narrower in patients with IDA than in healthy non-anemic individuals suggests that vascular caliber may reflect early microvascular alterations resulting from IDA. Added to that, hemoglobin level was associated with CRAE and CRVE in our linear regression analysis of patients with IDA. Certain changes in retinal vascular caliber are also clearly associated with high blood pressure, cardiovascular risk, and mortality. It may be critical to identify all alterations in retinal vascular caliber in order to prevent potential ocular and systemic disorders in patients with IDA.

Retinal vascular findings in patients with COVID-19.

PURPOSE: The purpose of this study was to compare the retinal vascular caliber of COVID-19 patients with that of healthy subjects. METHODS: This was a prospective case-control study. Forty-six patients who had COVID-19 were successfully treated, and 38 age- and gender-matched healthy subjects were enrolled in this study. Fundus photography was taken using fundus fluorescein angiography (FA; Visucam 500; Carl Zeiss Meditec, Jena, Germany). Retinal vascular caliber was analyzed with IVAN, a semi-automated retinal vascular analyzer (Nicole J. Ferrier, College of Engineering, Fundus Photography Reading Center, University of Wisconsin, Madison, WI, USA). Central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery-vein ratio (AVR) were compared between groups. RESULTS: The mean age was 37.8 ± 9.5 years in the COVID-19 group (n = 46) and 40 ± 8 years in the control group (n = 38) (p = 0.45). The mean CRAE was 181.56 ± 6.40 in the COVID-19 group and 171.29 ± 15.06 in the control group (p = 0.006). The mean CRVE was 226.34 ± 23.83 in the COVID-19 group and 210.94 ± 22.22 in the control group (p = 0.044). AVR was 0.81 ± 0.09 in the COVID-19 group and 0.82 ± 0.13 in the control group (p = 0.712). CONCLUSION: Patients who had COVID-19 have vasodilation in the retinal vascular structure after recovery. As they may be at risk of retinal vascular disease, COVID-19 patients must be followed after recovery.

The association between markers of inflammation and retinal microvascular parameters: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Adverse changes to the microcirculation play an important role in the pathogenesis of cardiovascular disease (CVD), and inflammation is a key causal mechanism. We investigated the relationship between inflammatory markers and retinal microvascular parameters. METHODS: Studies up to April 2021 were identified in Medline, Embase and PubMed with the following terms: retinal microvascular parameters, inflammatory markers, and observational studies. Correlation coefficients of inflammatory markers and retinal vascular caliber were pooled using the random-effects model. RESULTS: Of 4783 studies identified, 36 met the inclusion criteria (general population 26, patients with diseases 10). C-reactive protein (CRP) and white blood cell count (WBC) were most frequently reported. We conducted meta-analysis with 12 CRP studies (22422 participants) and six WBC studies (15209 participants), and also performed a narrative review of all studies. There was consistent evidence of a modest association between CRP and venular caliber (r = 0.09, 95%CI 0.05 to 0.12), but little evidence of an association between CRP with retinal arteriolar caliber (r = 0.00, 95%CI -0.02 to 0.02). Similarly, WBC had stronger associations with venular (r = 0.18, 95%CI 0.05 to 0.31) than arteriolar caliber (r = 0.05, 95%CI 0.01 to 0.09). Narrative review of other inflammatory markers showed consistent findings. There was little evidence of associations between inflammation markers and other microvascular parameters, fractal dimension and tortuosity. CONCLUSIONS: There was more evidence for an association of inflammation with retinal venular than with arterial caliber. The findings suggest a potential druggable mechanism contributing to microvascular damage that has been relatively overlooked in CVD pathogenesis and treatment.

Retinal Vascular Caliber Association with Nonperfusion and Diabetic Retinopathy Severity Depends on Vascular Caliber Measurement Location.

PURPOSE: To evaluate the association of retinal nonperfusion and diabetic retinopathy (DR) severity with location of vascular caliber measurement using ultrawide field (UWF) imaging. DESIGN: Retrospective image review. PARTICIPANTS: Adults with diabetes mellitus. METHODS: All images from subjects with same-day UWF fluorescein angiography (FA) and color imaging were evaluated. Predominantly peripheral lesions (PPL) and DR severity were graded from UWF color images. Nonperfusion was quantified using UWF-FA in defined retinal regions [posterior pole (PP), mid-periphery (MP), far-periphery (FP)]. Retinal vessel calibers were measured at an optic disc centered inner and outer zone. MAIN OUTCOME MEASURES: Nonperfusion index (NPI) in the PP, MP and FP. Mean arteriole and venule diameter in the inner and outer zones. RESULTS: Two hundred eighty-five eyes of 193 patients (24.9% mild nonproliferative DR [NPDR], 22.8% moderate NPDR, 37.5% severe NPDR and 14.7% proliferative DR [PDR]) were reviewed. No significant associations between inner zone arteriolar diameter and retinal NPI overall or in any retinal region. In the outer zone, eyes with thinnest arteriolar calibers (quartile 1) were associated with a 1.7- to 2.4-fold nonperfusion increase across all retinal regions compared to the remaining eyes (P = 0.002 [PP] to 0.048 [FP]). In the outer zone, the percentage of eyes in the thinnest quartile of retinal arteriolar diameter increased with worsening DR severity (mild NPDR: 10% vs PDR: 31%, P = 0.007). This association was not observed when measured within the inner zone (P = 0.129). All venular caliber associations were not statistically significant when corrected for potentially confounding factors. Thinner outer zone retinal arteriolar caliber (quartile 1) was more common in eyes with PPL compared to eyes without PPL (34.1% vs 20.8%, P = 0.017) as were thicker outer venular calibers (quartile 4) (33% vs 21.3%, P = 0.036). Presence of PPL was associated with thinner outer zone arteriolar caliber (109.7 ± 26.5µm vs 123.0 ± 29.5µm, P = 0.001). CONCLUSIONS: The association of vascular caliber with nonperfusion and DR severity differs based upon the retinal location at which vascular caliber is measured. Peripheral arterial narrowing is associated with increasing nonperfusion, worsening DR severity and presence of PPL. In contrast, inner zone retinal arteriolar caliber is not associated with these findings.

Retinal Vascular Caliber and Kidney Function in Children and Adolescents with Type 1 Diabetes.

PURPOSE: To evaluate the relationship between retinal vascular caliber and kidney function in a cohort of Australian children and adolescents with type 1 diabetes. METHODS: This was a cross-sectional study of 483 children and adolescents with type 1 diabetes, aged 7-18 years. An audit of medical files of participants who attended the Royal Children's Hospital, Melbourne, between January 2009 and March 2014 was performed. Albumin to creatinine ratio (ACR) was acquired through spot urine samples and microalbuminuria was classified as ACR >3.5 mg/mmol in females and >2.5 mg/mmol in males. Retinal vascular caliber was measured using a standardized protocol and later summarized as central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). RESULTS: CRAE was significantly narrower in participants with microalbuminuria compared to those with normo-albuminuria in crude analysis (mean ± standard deviation 159.07 ± 9.90µm vs 164.49 ± 12.45 µm; p = 0.006). After adjustment for key confounders and known or potential mediators of microalbuminuria (age, sex, ethnicity, hemoglobin A1c, systolic blood pressure, total cholesterol, body mass index, duration of diabetes and CRVE) the association between narrower CRAE and microalbuminuria was attenuated and was no longer significant (95% confidence interval 0.94-1.02, p = 0.222). No significant associations between CRVE or arteriole-to-venule ratio and microalbuminuria were observed in univariate or multivariate models. CONCLUSIONS: After adjustment for potential confounding variables, retinal vascular caliber was not significantly associated with microalbuminuria in this sample of children and adolescents with type 1 diabetes. Future prospective longitudinal research is warranted to further evaluate these findings.

Personality and Total Health Through Life Project Eye Substudy: Methodology and Baseline Retinal Features.

PURPOSE: To describe the methodology and present the retinal grading findings of an older sample of australians with well-defined indices of neurocognitive function in the Personality and total Health (PATH) through life project. DESIGN: A cross-sectional study. METHODS: Three hundred twenty-six individuals from the PatH through life project were invited to participate. Participants completed a general questionnaire and 2-field, 45-degree nonmydriatic color digital retinal photography. Photographs were graded for retinal pathology according to established protocols. RESULTS: Two hundred fifty-four (77.9%) subjects, aged 72 to 78 years, agreed to participate in the eye substudy. gradable images of at least 1 eye were acquired in 211 of 254 subjects (83.1%). retinal photographic screening identified 1 or more signs of pathology in 130 of the 174 subjects (74.7%) with gradable images of both eyes. a total of 45 participants (17.7%) had self-reported diabetes and diabetic retinopathy was observed in 22 (48.9%) of these participants. CONCLUSIONS: This well-defined sample of older australians provides a unique opportunity to interrogate associations between retinal findings, including retinal vascular geometric parameters, and indices of neurocognitive function.

Update on retinal vascular caliber.

Retinal vessels are the only blood vessels that can be viewed directly, in vivo, repetitively and non-invasively. Retinal vessel caliber is influenced by physiological (age, sex, race, blood pressure, blood glucose, body mass index) and pathological (atherosclerosis, dyslipidemia, smoking) determinants. There are studies on large population groups that demonstrate the associations between retinal vasculature and subclinical or clinical changes in systemic diseases (hypertension, diabetes, stroke, renal or cardiac diseases). The assessment of retinal vessels can provide information about the pathophysiology of many diseases, but it also has a direct applicability in clinic, being used as a screening method that predicts the risk of their occurrence.

Retinal vessels caliber changes after strabismus surgery: results of 6mo follow-up.

AIM: To evaluate the effect of strabismus surgery on retinal vessels calibers with digital color fundus photographs. METHODS: Two hundred consecutive strabismus patients underwent surgery, and 118 patients (female/male, 55/63) who finished 6-month follow-up were finally included in this study. Optic disc-centered digital color fundus photographs of both eyes of all patients were taken prior to surgery and 6mo post surgery. The retinal vascular caliber of 116 operated eyes were measured using the computer program IVAN. The operated eyes were divided into 3 groups according to the surgical methods, recession of one muscle, one muscle recession and one muscle folding, one muscle resection and one muscle recession. The effect of number of altered muscles on retinal vessels was analyzed using statistic software SPSS 16.0. RESULTS: The mean age was 12.4±8.6y. Averaged central retinal artery equivalent (CRAE) of all patients was 120.31±23.02 µm preoperatively, and 122.87±15.93 µm six months after surgery. Averaged central retinal vein equivalent (CRVE) was 171.11±31.73 µm preoperatively and 175.02±21.00 µm postoperatively. There was no significant difference of averaged CRAE (P=0.22) or CRVE (P=0.19) before and after operation. Averaged arteriole to venule ratio (AVR) was 0.71±0.07 before surgery and 0.70±0.07 after surgery. Comparison of preoperative and postoperative retinal vessels calibers among different surgical groups did not show significant differences. Also, there was no advantage of rectus muscle folding to muscle resection. CONCLUSION: Up to 6mo after strabismus surgery, the retinal vascular calibers were not altered. No more than two muscles in one surgery are safe for retinal perfusion.

Late Postoperative Evaluation of Retinal and Choroidal Thickness and Retinal Vessel Caliber after Surgical Repair of Corneal Perforation.

OBJECTIVES: To examine the late period retinal and choroidal alterations in the posterior pole of eyes that underwent primary suturing due to traumatic corneal perforation. MATERIALS AND METHODS: This cross-sectional case series included 21 eyes of 21 patients. The fellow eyes served as the control group. Macular thickness, peripapillary retinal nerve fiber layer (RNFL) thickness, choroidal thickness, and retinal vessel caliber measurements were performed by spectral-domain optical coherence tomography (SD-OCT). RESULTS: The mean RNFL thickness was 102.1±10.9 µm in the perforated eyes and 99.5±8.5 µm in the fellow eyes (p=0.29). The mean central macular thickness was 300.1±25.6 µm in the perforated eyes and 295.6±23.2 µm in the fellow eyes (p=0.62). The choroidal thickness and retinal vascular caliber measurements were also similar between the groups (p>0.05). CONCLUSION: Operated traumatic corneal perforations do not cause significant posterior pole retinal and choroidal SD-OCT thickness changes in the late postoperative period.