الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 126 |  |  |
| | | from | 126 | | |
Abstract
The most frequent side effect of diabetes mellitus (DM), diabetic retinopathy (DR), is a major global cause of blindness.
Damage to the systemic macro- and microvasculature in people with DM, including the disease diabetic retinopathy (DR), comes from poor glycemic control.
There are 2 type of DR: non-proliferative (NPDR) and proliferative (PDR). Intraretinal haemorrhages, hard exudates, microaneurysms, and capillary non-perfusion are characteristics of NPDR.
And pdr is characterized by Fine to severe loops of new vessels that may grow on the optic disc: neovascularization of the disc (NVD) or elsewhere (NVE) In the anterior segment, PDR is manifested by neovascularization of the iris (NVI), the angle (NVA) and may eventually complicated with neovascular glaucoma These new vessels may leak and resulting in retinal edema. They are also fragile and prone to bleed Opaque fibrovascular proliferation tissue often appears on the internal limiting membrane (adjacent to the new vessels) and becomes adherent to the vitreous Contraction of this fibrovascular tissue may lead to:
Distortion or dragging of the macula, Mild to extensive retinal detachment, Avulsion of retinal vessels and vitreous hemorrhages
Numerous approaches were created, such as colour Doppler imaging and laser Doppler velocimetry. Doppler OCT and scanning laser ophthalmoscopy using adaptive optics. Even though these highly specialised tools were almost exclusively employed in research settings, some of the early DR literature’s conclusions were contradictory.
Optical coherence tomography angiography (OCTA) is an innovative tool for examining retinal microvessels in vivo and accurately measuring the thickness of the retinal pigment epithelium (RPE). Several studies have described the use of OCTA to evaluate DR.
The aim of the present study was to assess different parameters of quantitative retinal optical coherence tomography angiography in patients with type 2 diabetes without diabetic retinopathy.
In the present study, the mean age of Diabetic group was 56.6±3.13 years while mean age was 54.7±4.4 in control group. There is no statistically difference between studied diabetes mellitus type 2 patients and control group regarding to age or sex.
Mean duration of disease in the present study was 12.1±1.7 and ranged from (10-15) years, Mean HBA1c of all patients was 7.8±0.28 and ranged from (7.3-8.2). The studied diabetes mellitus type2 group were 7 with controlled diabetes (70.0%) and 7 diabetic were treated by oral hypoglycemic (70.0%)
On comparing morbidity of both groups 6 diabetic patients had associated comorbidities, distributed as 4 hypertension, one hepatic impairment, other one with renal impairment ,While control group 3 participants had hypertension, one hepatic impairment, difference statistically insignificant p>0.05
Median of uncorrected visual acuity was 0.3 with range (0-0.5) measured in diabetic group versus control group was 0.2 with range (0-0.5) p=0.24. Best corrected visual acuity showed no significant difference among both groups p=0.25
In the present study, There is no statistically difference between studied diabetes mellitus type 2 patients and control group regarding to un corrected visual acuity or best corrected visual acuity (p>0.05).
Mean of intraocular pressure was 14.2 and ranged 12 to 18 for diabetic group, versus 13.6 and ranged 11 to 17 for control group the difference insignificant p=0.195
There is no statistically difference between studied diabetes mellitus type2patients and control group regard to FAZ diameters p=0.175
Quantities retinal optical coherence tomography angiography measure of mean whole image of superficial capillary plexus , in diabetic eyes was
44.5±2.9 with range 40.5-49.7 , significantly smaller than control group with mean 48.8±3.9 and range 42.6-55.4, p<0.0001,.
Parafoval superficial capillary plexus was 47.3±3.5 with range38.1-53.5 in diabetic eyes versus mean 48.8±3.9 with range 42.6-55.4 in control eyes, p<0.0001. Measuring whole image of deep capillary plexus , in diabetic eyes was 46.8±6.5 with range 38.9-62.8, significantly smaller than control eyes with mean 51.7±3.9 and range 46.1-59.7, p<0.0001,.Parafoval deep capillary plexus was 50.1±6.9 with range41.6-67.2, in diabetic eyes versus mean 55.8±4.4 with range 49.3-65.1in control eyes p=0.0001
In the present study There is a significant and inverse relation between HBA1c and superficial whole image, Whereas, there is significant direct relation between BCVA, and deep whole image, deep parafoval, Otherwise there is no relation between other parameters
Regarding significant predictor for diabetic eye affection it was sup Para fovea ≤52, deep Para fovea ≤52.43, superficial image ≤47.65and Deep image
≤47.65 which was a significantly predictor for diabetic eye affection.
In conclusion, quantitative OCTA measures may have a role in detecting subclinical disease and diabetic patients who have a risk of developing diabetic retinopathy.