4. Retinal findings
Retinal hemorrhages
i.Superficial
Flame shaped hemorrhages (Figure 4.1)
-bleeding near the surface of retina in nerve fiber layer
-follows nerve fiber, giving flame shaped appearance
-located usually in relation to optic nerve head or posterior pole, seldom in peripheral retina where nerve fiber layer is thin.
-cause: retinal vein occlusion due to hypertensive retinopathy, diabetic retinopathy, optic nerve disease (acute papilloedema, anterior ischemic optic neuropathy), retinal periphlebitis
Figure 4.1 Flame Shaped hemorrhage
Notice the unidirectional smudge-smear like of the hemorrhage, forming the characteristic flame appearance.
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ii. Deep
Dot and blot hemorrhages (Figure 4.2)
-bleed from deep retinal capillaries
-dot hemorrhages are small round and with uniform density
-blot hemorrhaes are larger, with irregular shape and density, forming an irregular patch of bleeding, and darker in color
-dots and blots are mostly found in the peripheral retina where retinal nerve fiber is thin
-causes: retinal vein occlusion, non-proliferative diabetic retinopathy
Figure 4.2 A clear cut dots and blots hemorrhage appearance
Subretinal Hemorrhage (Figure 4.3)
•Bleeding between the photoreceptors and retinal pigment epithelium
•Usually large and bright red with indistinct margin
•Vessels are clearly seen above the hemorrhage
•Causes: choroidal neovascularization, retinal tear, Coat’s disease, sickle cell anemia, blunt trauma
Figure 4.3 Subretinal hemorrhage
Note that the vessels are crossing above the hemorrhage area.
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Preretinal Hemorrhage (Figure 4.4)
•Bleeding on the surface of retina, between the retina and hyaloid membrane of vitreous
•Usually solitary and located at the posterior pole
•Well defined margin with vessels sometimes seen crossing below the hemorrhage area.
•Initally round but later settle with gravity, giving the “boat-like” apperance due to pooling of the blood.
•Causes: Proliferative retinopathy, retinal artery macroaneurysm, trauma
Figure 4.4 Subretinal hemorrhage
A round subretinal hemorrhage (left) with vessels seen crossing below it. The picture on the right show a large subretinal hemorrhage which settled into a boat-like appearance or pooling of blood.
Cotton Wool Spots
•Represents microinfarction of the nerve fiber layer of the retina
•Consist of axoplasmic debris
•small, white, superficial lesions with indistinct margin, giving it a fluffy appearance of cotton wool .
•Causes: Retinal vein occlusion, non-proliferative diabetic retinopathy, vasculitides (SLE, scleroderma), hypertensive retinopathy, AIDS microvasculopathy, microembolic retinal artery occlusion
Figure 4.5 Cotton Wool Spots
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Hard Exudate
•Leakage of high protein and lipid due to break in blood retinal barrier
•Yellowish glistening intraretinal lesion, usually with a welldefined margin.
•Commonly seen in:
1.Diabetes Mellitus
2.Uncontrolled hypertension
3.Any condition where there is abnormal blood vessel in the retina or choroid.
Figure 4.6 Hard Exudates
Notice the picture on the right where a circinate ring is being formed.
*In fundus with massive hard exudates, check the patient’s lipid profile for hypercholesteremia. It is essential to control the cholesterol level as well!