Ocular and systemic vascular alterations in overweight and obese individuals undergoing weight-loss interventions

Abstract

Obesity and its accompanying comorbidities play a crucial role in the pathogenesis of endothelial function which is a pre-cursor to atherosclerosis, subsequently leading to increases in cardiovascular risk. However, amelioration of these risk factors and improvements in endothelial function have never been fully explored in functional assessments of the retinal and peripheral microcirculations.The aim of this thesis was therefore to investigate the presence and impact of weight-loss interventions in overweight and obese individuals and also the relationships between functional measurements of different vascular beds.
The principle findings of this work were:1. The relationship between retinal and peripheral vascular function in healthy individuals with low cardiovascular risk• Participants with higher peripheral vascular reactivity indices had a higher amplitude change from maximum to minimum and also showed enhanced reaction times to flicker provocation, which correlated to the degree of peripheral vascular function.
2. The effects of physical training on retinal and systemic microvascular function• Physical exercise positively influenced the retinal microcirculation through improvements in dilation and constriction reaction times to flicker provocation.
3. The long-lasting effects of fasting during the month of Ramadan on retinal and peripheral vascular function• Participants during fasting had a higher capacity to reach maximum dilation and also a greater percentage increase from baseline diameters. The retinal veins were also significantly less variable during baseline corrected measurements.
4. The effect of bariatric surgery on retinal vessels structure and systemic microvascular function• Increases were recorded for the diameter of retinal arteries but also for the veins. Peripheral vascular function was significantly improved and arterial stiffness was decreased. CVD risk was significantly decreased and also correlated with retinal vessel calibre measurements.
5. Is there an improvement in anterior ocular health after bariatric surgery?• Anterior surface health doesn’t necessarily cause ocular health problems in obese individuals nor can it be improved or ameliorated through bariatric surgery

Date of Award	15 Aug 2018
Original language	English
Supervisor	Doina Gherghel (Supervisor)