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Title: Non-perfusion in retinal vascular diseases and its association with neovascularisation and retinal vessel oxygenation
Author: Nicholson, Luke
ISNI:       0000 0004 7964 8597
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2019
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Diabetic retinopathy (DR) and retinal vein occlusion (RVO) are the two commonest retinal vascular diseases. The main pathology in this condition is the effect on retinal perfusion that plays a significant role in its neovascular complications. Retinal non-perfusion also effects the oxygen delivery and consumption of the retina. In this thesis, the relationship between retinal non-perfusion in retinal vascular diseases and its association with neovascularisation and retinal vessel oxygenation were assessed. To quantify retinal non-perfusion, a validated and reliable measurement tool, the concentric rings method, was developed to accurately quantify retinal non-perfusion using UWF angiography. Distortions based on the angular location were identified from UWF imaging and these were quantified using a 3-D printed model eye. Adjustments were then made on the validated tool based on the distortions identified to accurately quantify retinal non-perfusion on UWF angiography. The clinical impact of retinal non-perfusion and neovascularisation was further studied in DR and RVO using the concentric rings method developed. Posterior pole non-perfusion appeared to play an important role in determining the risk of developing neovascularisation in eyes with central retinal vein occlusion. In diabetic retinopathy, by studying the area and distribution of retinal non-perfusion, peripheral retina ischaemia appears to be significant in retinal neovascularisation in proliferative DR, but posterior and peripheral retinal non-perfusion appears the determinant for disc new vessels. The impact of panretinal laser treatment and intravitreal anti-VEGF in proliferative DR on retinal oxygenation and retinal non-perfusion was studied with no significant differences between both treatment modalities on these parameters. Finally, studying the quantity and spatial location of retinal non-perfusion and its relationship with retinal oximetry, the arterio-venous difference measured using retinal oximetry correlated with the area of retinal non-perfusion in the posterior retina but has no significant relationship with ischaemia in the periphery.
Supervisor: Bainbridge, J. ; Sivaprasad, S. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available