الفهرس 
Blood supply of the RetinaOnly 14 pages are availabe for public view
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Abstract
Diabetic retinopathy (DR) is still one of the leading causes of blindness
worldwide, affecting about one-third of diabetic patients.
Fluorescein angiography is currently the gold standard for evaluating the
retinal vasculature. However, it provides a limited visualization of the deep retinal
and choroidal vessels and has potential side effects. OCTA is a novel application
of Optical Coherence Tomography (OCT) technology. It’s a fast, non-invasive
imaging of microvasculature blood flow in the retina and choroid within seconds
and may provide quantitative analytical information.
The aim of this study was to compare FFA and OCTA in evaluation of diabetic
maculopathy.
This comparative case control study included 54 patients with DR from
Retina Clinic at the Ophthalmology Department in Menoufia University Hospital
and Tanta Ophthalmology Hospital and 54 control subjects who were enrolled
during the period from January 2021 to June 2021 after explaining the purpose of
the study to them. Patients with type 1 or 2 diabetes, older than 18 years old and
with any diabetic retinal changes were included while patients below 18 years old,
patients treated with any DR treatment modality or patients having retinal disorders
other than DR were excluded.
A full general and ophthalmic history was taken and complete ocular
examination were performed. Color fundus photography, FFA, OCT and OCTA
were performed on the same day. OCT and OCTA was done using Cirrus HDOCT 5000 (Zeiss, Meditec AG, Goeschwitzer Strasse 51-52, 07745 Jena,
Germany, equipped with AngioPlex module). Scanning region was 3x3 mm area.
Summary
62
And by a digital retinal camera (Visucam 500, Carl Zeiss, Meditec AG,
Goeschwitzer Strasse 51-52, 07745 Jena, Germany) color fundus images and FFA
were captured. DR was categorized using the international clinical DR disease
severity scale into proliferative diabetic retinopathy (PDR) and mild, moderate,
and severe nonproliferative diabetic retinopathy (NPDR). FFA and OCTA findings
were summarized and compared.
The study included 54 patients with age range from 44-68 years (mean=59.4
± 8.5 years), with equal sex distribution. There were no statistically significant
differences between the study group and the control group regarding age and sex
(P>0.05)
In the study group, 7 (13%) patients were insulin dependent, and 47 (87%)
were non-insulin dependent. The duration of ranged between 5-15 years
(mean=10.4 ± 3.4 years). Among the patients with DM.
The distribution of DME patterns by FFA showed that diffuse leakage at
macula was the most common pattern (37.9% of the eyes) followed by focal
macular leakage in 18.4% of the eyes, and cystoid leakage in 8% of the eyes, while
35.5% of the eyes showed no edema. The DR grading showed that from the
NPDR patients, 13 (14.9%) were mild, 19 (21.8%) were moderate, and 37 (42.5%)
were severe, while 18 (20.7%) patients had PDR.
Using OCTA, 54 patients with DR were compared with 54 healthy controls
(26 females and 28 males). The mean foveal avascular zone (FAZ) area was
statistically significantly smaller in the healthy control group (0.246±0.059
mm²) than in the diabetic group (0.544±0.230 mm²) (P=0.001). The VD results
appeared to be an important biomarker in the diabetic patients as the mean VD of
the superficial capillary plexus (SCP) was statistically significantly higher in the
healthy control group (69.638±3.89%) than in the diabetic group (61.325±11%)
Summary
63
(P<0.001). Similarly, the mean VD of the deep capillary plexus (DCP) was
statistically significantly higher in the healthy control group (61.901±2.023%) than
in the diabetic group (53.58±10.56%) (P<0.001). In addition, the mean macular
thickness of the healthy control group (240.05±2.43 µm) was statistically
significantly less than in the diabetic group (267.76±48.41 µm) (P=0.001).
The OCTA was superior to FFA in the diagnosis of DMI. The FAZ was
ischemic (enlarged) in 74 (85.06%) eyes on OCTA compared to only 46 (52.87%)
eyes by FFA, with a statistically significant difference (P=0.001). In addition, the
OCTA detected MAs in all cases while FFA could detect them only in 70 (80.46%)
eyes, with a statistically significant difference (P=0.001). The number of MAs
detected by OCTA was also significantly higher.
In the DR group, the mean FAZ area of the eyes with intact FAZ (0.4±0.1
mm
2
) was significantly smaller than in the ischemic eyes (0.7±0.2 mm
2
),
(U=56.602, p<0.001), while the SCP VD and the DCP VD in the eyes with intact
FAZ (69.2±5% and 61.0±4.1%, respectively) was statistically significantly higher
than in the ischemic eyes (54.3%±10.1% and 47.0±9.6%, respectively),
(U=36.984, p<0.001 and U=35.955, p<0.001, respectively)