Georgia Siasou

Role of Endothelial Dysfunction and Arterial Stiffness in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR) remains one of the most important diabetic microvascular complications and a leading cause of irreversible blindness, highlighting the importance of close monitoring. The atherosclerotic progression in patients with insulin resistance is precipitated by endothelial dysfunction and vascular impairment (1). Therefore, we examined the association of endothelial dysfunction and arterial stiffness with DR and how these measurements can be used for the early identification and monitoring of patients at high risk to develop DR. In this case-control study, we included 100 healthy control (CL) subjects and 200 consecutive subjects with type 2 diabetes recruited from the 1st Department of Ophthalmology of the University of Athens Medical School where they were referred to evaluate for DR. All participants underwent a complete ophthalmological examination by the same experienced ophthalmologist, which included fundoscopy after pupillary dilation, fluorescein angiography, and colorful fundus photographs. The diabetic patients, according to the Early Treatment Diabetic Retinopathy Study (ETDRS) classification, were categorized into three groups: 1 ) no DR (NDR) (108 …

Vascular function and ocular involvement in sarcoidosis.

Ocular involvement occurs in sarcoidosis (Sar) patients mainly in the form of uveitis. This study was designed to determine if uveitis in Sar patients is associated with vascular impairment. We enrolled 82 Sar patients and 77, age and sex matched, control subjects (Cl). Sar patients were divided into those with ocular sarcoidosis (OS) and those without ocular sarcoidosis (WOS). Endothelial function was evaluated by flow-mediated dilation (FMD). Pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) as a measure of arterial wave reflections. Although there was no significant difference in sex, age and mean arterial pressure, patients with OS compared to WOS patients and Cl subjects had impaired FMD (p<0.001), increased AIx (p=0.02) and increased PWV (p=0.001). Interestingly, impaired FMD in Sar patients was independently, from possible covariates (age, sex, smoking habits, arterial hypertension, dyslipidemia), associated with increased odds of ocular involvement (odds ratio=1.69, p=0.001). More precisely ROC curve analysis revealed that FMD had a significant diagnostic ability for the detection of OS (AUC=0.77, p<0.001) with a sensitivity of 79% and a specificity of 68% for an FMD value below 6.00%. To conclude in the present study we have shown that ocular involvement in Sar patients is associated with impaired endothelial function and increased arterial stiffness. These results strengthen the vascular theory which considers uveitis a consequence of vascular dysfunction in Sar patients and reveals a possible clinical importance of the use of endothelial function tests.

Visual problems in young adults due to computer use.

BACKGROUND Computer use can cause visual problems. The purpose of our study was to evaluate visual problems due to computer use in young adults. PATIENTS AND METHODS Participants in our study were 87 adults, 48 male and 39 female, mean aged 31.3 years old (SD 7.6). All the participants completed a questionnaire regarding visual problems detected after computer use. RESULTS The mean daily use of computers was 3.2 hours (SD 2.7). 65.5 % of the participants complained for dry eye, mainly after more than 2.5 hours of computer use. 32 persons (36.8 %) had a foreign body sensation in their eyes, while 15 participants (17.2 %) complained for blurred vision which caused difficulties in driving, after 3.25 hours of continuous computer use. 10.3 % of the participants sought medical advice for their problem. There was a statistically significant correlation between the frequency of visual problems and the duration of computer use (p = 0.021). 79.3 % of the participants use artificial tears during or after long use of computers, so as not to feel any ocular discomfort. CONCLUSIONS The main symptom after computer use in young adults was dry eye. All visual problems associated with the duration of computer use. Artificial tears play an important role in the treatment of ocular discomfort after computer use.

Assessment of the macula in keratoconus: an optical coherence tomography and multifocal electroretinography study.

Purpose: The purpose of our study was to assess the macular thickness and the electrophysiological changes in keratoconic patients without any systemic or ocular disorders. Methods: 64 eyes of 32 keratoconus patients as well as 60 eyes of 30 controls participated in the study. All participants underwent a complete ophthalmological examination, including best-corrected visual acuity (BCVA) assessment, color vision testing, fundus examination, intraocular pressure measurement, central foveal thickness (CFT) measurement by optical coherence tomography (OCT) scan, and multifocal-electroretinogram (mf-ERG) recording. CFT, retinal response density (RRD) and P1 latency were measured. Results: There was no statistically significant difference between the two groups concerning CFT and P1 latency in mf-ERG. The RRD in mf-ERG differed significantly between keratoconus patients and controls. Of note, BCVA was positively associated with RRD in keratoconus patients. Conclusion: In some cases of keratoconus, a macular dysfunction not visible ophthalmoscopically may coexist and the low visual acuity could be due not only to the corneal abnormality, but also to the photoreceptor dysfunction. As a result, the preoperative electrophysiological study of patients with keratoconus is crucial to avoid a needless corneal transplantation.

RELATIONSHIPS BETWEEN GLAUCOMA, ARTERIAL STIFFNESS AND INFLAMMATORY PROCESS

Background: Reduced ocular blood flow, mostly caused by vascular dysregulation, plays a pivotal role in the pathogenesis of primary open-angle glaucoma (POAG). Glaucoma is also associated with peripheral vascular endothelial dysfunction. However the effect of POAG on vascular function and the inflammatory process is unknown. Therefore in the present study we evaluate arterial stiffness and inflammatory process in patients with POAG.

THE IMPACT OF ENDOTHELIAL DYSFUNCTION IN THE DEVELOPMENT OF DIABETIC RETINOPATHY: ROLE OF INFLAMMATION

Diabetic Retinopathy (DR) is a leading cause of blindness. Measurement of endothelial function and arterial stiffness are associated with adverse cardiovascular outcomes. We investigated the possible association of DR with endothelial function, arterial stiffness and inflammation. We enrolled 100

IMPAIRED ENDOTHELIAL FUNCTION AND INCREASED ARTERIAL STIFFNESS IN PATIENTS WITH DIABETIC RETINOPATHY

Diabetes Mellitus is associated with endothelial dysfunction and arterial stiffness. Diabetic Retinopathy (DR) is a complication of diabetes mellitus and remains a leading cause of irreversible blindness. We investigated the possible association of DR with endothelial function, arterial stiffness

FAVORABLE EFFECTS OF L-ARGININE ON ARTERIAL FUNCTION, INFLAMMATORY AND FIBRINOLYTIC PROCESS IN SMOKERS

Methods: We studied the effect of a 3-day oral administration of l-arginine in 12 healthy smokers (24±3yrs) on 3 occasions (day0:baseline,day1,day3). The study was carried out on two separate arms, one with l-arginine (3x7gr/d) and one with placebo (randomized,placebo-controlled,double-blind,cross-over design).Measurements were carried out before and 20 minutes after cigarette smoking. Endothelial function was evaluated by flow-mediated dilatation (FMD)of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx)as a measure of arterial wave reflections. Circulating levels of soluble intercellular cells adhesion molecule (s-ICAM-1) and tissue plasminogen activator (tPA) were measured by ELISA.