Changes of retinal structure and function in patients with internal carotid artery stenosis.

BACKGROUND: To investigate the structural and functional changes of the retina in patients with different degrees of internal carotid artery (ICA) stenosis. METHODS: This cross-sectional study included patients with varying degrees ICA stenosis. Clinical characteristics of 41 patients were collected after being divided into four groups according to the ICA stenosis indicated by computed tomographic angiography (Group 0: without ICA stenosis, Group 1: ipsilateral slight ICA stenosis, Group 2: ipsilateral moderate ICA stenosis, Group 3: ipsilateral severe ICA stenosis). Retinal vessel caliber (RVC) was measured quantitatively with the Integrative Vessel Analysis software. The retinal sensitivity was examined with the MP-3 microperimeter. The relationships among central retinal artery equivalent (CRAE), central retinal vein equivalent, arteriole to venule ratio (AVR), mean retinal sensitivity (MS) and ICA stenosis degree were analysed. RESULTS: The CRAE in Group 3 were significantly smaller compared with Group 0, Group 1 and Group 2 (P < 0.001, P < 0.001, P = 0.002). Significant decrease was found between Group 3 with other groups in MS at fovea (P < 0.001, P < 0.001, P = 0.002). Moreover, there was a positive correlation found between MS and CRAE (Beta = 0.60, P < 0.001 at fovea; Beta = 0.64, P < 0.001 at 2 degree; Beta = 0.60, P < 0.001 at 4 degree; Beta = 0.55, P < 0.001 at 8 degree; Beta = 0.53, P < 0.001 at 12 degree). CONCLUSIONS: The present study revealed smaller CRAE and AVR in ipsilateral severe ICA stenosis patients. And the MS decreased in patients with severe ICA stenosis. In addition, MS had a positive correlation with CRAE.

Retinal main vessel calibers and systemic markers for long-term development of proliferative diabetic retinopathy.

PURPOSE: To evaluate if retinal vascular calibers and systemic risk factors in patients with no or minimal diabetic retinopathy (DR) can predict risk of long-term progression to proliferative diabetic retinopathy (PDR). METHODS: This was a matched case-control study of patients with diabetes having no or minimal DR at baseline with (cases) or without (controls) subsequent development of PDR. We collected six-field, 45-degree retinal images, demographic and clinical data from the Funen Diabetes Database. RESULTS: We included 52 eyes from 39 cases and 107 eyes from 89 controls matched on sex, age, type of diabetes, time from first to last screening episode and baseline DR level. Cases had higher HbA1c (73 vs. 55 mmoL/moL; p < 0.001), triglycerides (1.32 vs. 1.16 mmoL/L; p = 0.02) and longer duration of diabetes (19 vs. 14 years; p = 0.01), but the groups did not differ in calibers of retinal arterioles (229 vs. 227 µm; p = 0.49), venules (289 vs. 290 µm; p = 0.83) or the arterio-to-venule ratio (0.78 vs. 0.77; p = 0.86).In a multivariable logistic regression model with cluster robust standard error, HbA1c (OR 1.54 per 10 mmoL/moL; 95%-CI: 1.15-2.07; p = 0.004), triglyceride (OR 1.39 per 1 mmoL/L; 95%-CI: 1.03-1.86; p = 0.03) and duration of diabetes (OR 1.09 per year; 95%-CI: 1.03-1.16; p = 0.003) were independent risk factors for PDR. CONCLUSION: Retinal vascular calibers did not predict long-term development of PDR in contrast to well-established risk factors like HbA1c, triglyceride and duration of diabetes.

Small and large vessel disease in persons with unrecognized compared to recognized myocardial infarction: The Tromsø Study 2007-2008.

BACKGROUND: Unrecognized myocardial infarction (MI) is a frequent condition with unknown underlying reason. We hypothesized the lack of recognition of MI is related to pathophysiology, specifically differences in underlying small and large vessel disease. METHODS: 6128 participants were examined with retinal photography, ultrasound of the carotid artery and a 12­lead electrocardiography (ECG). Small vessel disease was defined as narrower retinal arterioles and/or wider retinal venules measured on retinal photographs. Large vessel disease was defined as carotid artery pathology. We defined unrecognized MI as ECG-evidence of MI without a clinically recognized event. We analyzed the cross-sectional relationship between MI recognition and markers of small and large vessel disease, adjusted for age and sex. RESULTS: Unrecognized MI was present in 502 (8.2%) and recognized MI in 326 (5.3%) of the 6128 participants. Compared to recognized MI, unrecognized MI was associated with small vessel disease indicated by narrower retinal arterioles (OR 1.66, 95% CI 1.05-2.62, highest vs. lowest quartile). Unrecognized MI was less associated with wider retinal venules (OR 0.55, 95% CI 0.35-0.87, lowest vs. highest quartile). Compared to recognized MI, unrecognized MI was less associated with large vessel disease indicated by presence of plaque in the carotid artery (OR for presence of carotid artery plaque in unrecognized MI 0.51, 95% CI 0.37-0.69). No significant sex interaction was present. CONCLUSIONS: Unrecognized MI was more associated with small vessel disease and less associated with large vessel disease compared to recognized MI. These findings suggest that the pathophysiology behind unrecognized and recognized MI may differ.

Sex-Specific Association of Obstructive Sleep Apnea With Retinal Microvascular Signs: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Obstructive sleep apnea (OSA) is a common condition affecting more men than women. The relationship of OSA with microvascular disease is unclear, complicated by possible sex difference. Assessment of the relationship of OSA with retinal microvascular signs in men and women may provide insights into such a relationship. METHODS AND RESULTS: We examined the sex-specific cross-sectional association of OSA severity with retinal vascular calibers in 1808 participants, and with specific retinopathy signs in 1831 participants from a sample of 2060 participants aged 54 to 93 years who underwent successful polysomnography in the Multi-Ethnic Study of Atherosclerosis, 2010-2012. OSA severity was defined by the apnea-hypopnea index (events/h) as none (<5), mild (5-14.9), moderate (15-29.9), and severe (≥30). As compared to no OSA, moderate/severe OSA in men was associated with retinal arteriolar narrowing (odds ratio [OR] and 95% CI for the narrowest quartile: 1.65 [1.00-2.71]) and retinal venular widening (1.80 [1.07-3.04] for the widest quartile), but not in women (odds ratio: 1.10 [0.67-1.81] and 0.91 [0.58-1.43], respectively) after adjusting for age, race/ethnicity, body mass index, pack-years of cigarette smoking, alcohol intake, hypertension duration, diabetes mellitus duration, HbA1c levels, lipid profile, micro-/macroalbuminuria, estimated glomerular filtration rate, ß-blockers use, antihypertensive therapy, and lipid-lowering therapy. In contrast, severe OSA was associated with retinal microaneurysms in women, but not in men (odds ratio: 3.22 [1.16-8.97] and 0.59 [0.27-1.30], respectively). CONCLUSIONS: The associations of OSA severity with retinal microvascular signs may differ by sex. Whether these findings were related to sex differences in OSA exposure needs further investigation.