Exaggerated relative nasal-temporal asymmetry of macular capillary blood flow in patients with clinically significant diabetic macular oedema.
OBJECTIVE
To compare the macular capillary blood flow of patients with clinically significant diabetic macular oedema (DMO) with that of non-diabetic subjects and to determine the relation between blood flow and capillary leakage in patients with DMO.


METHODS
The sample comprised 45 non-diabetic subjects (mean age 59 years) and 18 type 2 patients with clinically significant DMO (mean age 60 years). Macular capillary blood flow measurements were acquired using the Heidelberg retina flowmeter (HRF) and a 10 degrees x2.5 degrees scan field centred on the fovea. Fluorescein angiography was undertaken on each of the diabetic patients after the completion of HRF measurements.


RESULTS
Temporal macular capillary blood flow was significantly lower for the patients with clinically significant DMO compared with age matched non-diabetic subjects (ANCOVA, p = 0.0011) while relative nasal-temporal asymmetry of macular capillary blood flow was significantly higher (p = 0.0125). Nasal-temporal asymmetry of macular capillary blood flow was significantly higher for the patients with DMO and capillary leakage within the scan area (two tailed t test, p = 0.0071). Macular capillary blood flow was always lower in areas of DMO and capillary leakage.


CONCLUSIONS
Capillary blood flow was reduced in areas of DMO and capillary leakage, suggesting the presence of a localised perturbation of capillary blood flow regulation.
Hudson
C
C
University Department of Ophthalmology, Royal Eye Hospital, Manchester M13 9WH, UK. chudson@sciborg.uwaterloo.ca
Flanagan
J G
JG
Turner
G S
GS
Chen
H C
HC
Rawji
M H
MH
McLeod
D
D
D000368:Aged; D002196:Capillaries / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology*; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008266:Macula Lutea / Q000098:blood supply*; D008269:Macular Edema / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D012171:Retinal Vessels / Q000503:physiopathology