Patterns of peripheral retinal and central macula ischemia in diabetic retinopathy as evaluated by ultra-widefield fluorescein angiography.
OBJECTIVE
To investigate the association between peripheral and central ischemia in diabetic retinopathy.


METHODS
Retrospective, cross-sectional.


METHODS
Consecutive ultra-widefield fluorescein angiography images were collected from patients with diabetes over a 12-month period. Parameters quantified include the foveal avascular zone (FAZ) area, peripheral ischemic index, peripheral leakage index, and central retinal thickness measurements, as well as visual acuity. The peripheral ischemia or leakage index was calculated as the area of capillary nonperfusion or leakage, expressed as a percentage of the total retinal area.


RESULTS
Forty-seven eyes of 47 patients were included. A moderate correlation was observed between the peripheral ischemia index and FAZ area (r = 0.49, P = .0001). A moderate correlation was also observed between the peripheral leakage index and FAZ area, but only in eyes that were laser naïve (r = 0.44, P = .02). A thinner retina was observed in eyes with macular ischemia (217 ± 81.8 μm vs 272 ± 36.0 μm) (P = .02), but not peripheral ischemia (258 ± 76.3 μm vs 276 ± 68.0 μm) (P = .24). The relationships between different patterns of peripheral and central macular pathology and visual acuity were evaluated in a step-wise multivariable regression model, and the variables that remained independently associated were age (r = 0.33, P = .03), FAZ area (r = 0.45, P = .02), and central retinal thickness (r = 0.38, P = .01), (R(2)-adjusted = 0.36).


CONCLUSIONS
Ultra-widefield fluorescein angiography provides an insight into the relationships between diabetic vascular complications in the retinal periphery and central macula. Although we observed relationships between ischemia and vascular leakage in the macula and periphery, it was only macular ischemia and retinal thinning that was independently associated with a reduced visual function.
National Institute for Health Research, Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom; University College London, Institute of Ophthalmology, London, United Kingdom. Electronic address: dawnasim@gmail.com.
Dawn A
DA
Sim
National Institute for Health Research, Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom; University College London, Institute of Ophthalmology, London, United Kingdom.
Pearse A
PA
Keane
National Institute for Health Research, Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom; University College London, Institute of Ophthalmology, London, United Kingdom.
Ranjan
R
Rajendram
National Institute for Health Research, Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom.
Michael
M
Karampelas
University College London, Institute of Ophthalmology, London, United Kingdom.
Senthil
S
Selvam
University College London, Institute of Ophthalmology, London, United Kingdom.
Michael B
MB
Powner
University College London, Institute of Ophthalmology, London, United Kingdom.
Marcus
M
Fruttiger
National Institute for Health Research, Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom; University College London, Institute of Ophthalmology, London, United Kingdom.
Adnan
A
Tufail
National Institute for Health Research, Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom.
Catherine A
CA
Egan
D002199:Capillary Permeability; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D007511:Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology; D012171:Retinal Vessels / Q000473:pathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology