Central Retinal Artery Occlusion
It causes sudden, painless and complete loss of vision in elderly patients.
The most common causes are thrombosis and embolism.
Fovea centralis, which does not contain only nerve fibers, is seen in cherry red (Japanese flag appearance) color due to the red color of the underlying choroid.
Pupil mydriatic, weak or absent light reflex
Central Retinal Vein Occlusion
It causes sudden painless vision loss in elderly patients.
Since the blood reaching the retina with the central retinal artery is drained by the central retinal vein, the blood coming through the artery starts to accumulate in the retina in vein occlusions.
Papilla and borders are edematous.
There are intraretinal hemorrhages.
Central retinal vein occlusion and abundant soft exudate.
Hypertensive retinopathy
The most prominent manifestation of hypertension in the eye is narrowing of the arterioles.
Normally, while the artery/vein diameter ratio is 2/3, 1/2 decreases to 1/4.
If hypertension is associated with arteriosclerosis
Gunn (choking)
Salus (folding)
Humping (bridging)
Staging
Grade 1: Mild generalized retinal arteriolar narrowing
Grade 2: Increased generalized retinal arteriolar narrowing and focal arteriolar narrowing. Change of direction of veins in the area of A-V crossing (Salus sign). The copper wire landscape can begin at this stage.
Grade 3: Grade 2+retinal hemorrhages, hard and soft exudates, copper wire appearance. Enlargement of the veins distal to the arterial vein crossing region (Bonnet's sign). Wiping of veins at crossover sites (Gunn's sign) and full-angle bending of veins.
Grade 4: Severe grade 3+optic disc edema. Silver wire view in arteries.
Diabetic Retinopathy
Pericyte number decreased and endothelial number increased in retained capillaries.
Involves all three arteries, veins, and capillaries.
The involved vessel is clogged or leaking.
There is a close relationship between the duration of diabetes and retinopathy.
Physiopathology in diabetic retinopathy
- Microaneurysms
It is the first clinically detected lesion of diabetic retinopathy.
- retinal hemorrhages
It can be intraretinal, preretinal or intravitreal.
- exudates
Hard exudate: Chronic localized retinal occurs as a result of edema.
Soft exudate (cotton-wool spots): Debris formed as a result of ischemia of the nerve fiber layer.
- Venous changes
Venous dilatation is the earliest finding in diabetic retinopathy. However, it is difficult to evaluate clinically.
Venous pilling is the presence of sausage-like focal areas of narrowing and enlargement. It is an indicator of diffuse ischemia.
- Intraretinal microvascular anomalies (IRMA)
It is the development of abnormal vascular connections between arteries and veins in ischemic retinal areas.
- Retinal thickening and DME (diabetic macular edema)
It occurs as a result of disruption of the blood-retina barrier in diabetes.
- Neovascularization (most serious lesion)
vascular endothelial growth factor (VEGF) etc. in areas of retinal ischemia as an attempt to recover from hypoxia-induced cytokine release.
If the neovascularization is located on the optic disc or 1 disc diameter from the optic disc, it is called disc neovascularization (NVD), and if it is located anywhere in the retina, it is called retinal neovascularization (NVE).
