3. Retina
May affect the CRV, one, or more of its branches.
Types:
1. Central retinal vein (CRVO):
A. Non ischemic CRVO.
B. Ischemic CRVO.
2. Branch retinal vein occlusion:
A. Non ischemic.
B. Ischemic.
5. Retina
Central Retinal Vein Occlusion
Ischemic
Non ischemic
Marked loss of vision
Moderate loss of vision
Manifestations
Severe tortuosity and dilatation.
Moderate tortuosity and dilatation.
Venous changes
Flame-shaped or punctate (dot-
and-blot) all over the retina(severe)
Flame-shaped or punctate (dot-and-blot) all over
the retina (Moderate)
Retinal
hemorrhages
severe
Moderate
Disc edema.
Marked
Moderate
Macular edema.
severe
Moderate
Retinal edema.
Severe afferent pupillary defect.
Mild afferent pupillary defect.
Pupil
Marked
absent
Cotton wool exudate
NVs
No NVs
Fluorescein angiography
NVs
Macular edema
Cause of permanent
visual impairment
6. Retina
Complications:
Development of new vessels which may bleed leading to
vitreous hemorrhage.
Rubeosis iridis (iris neovessels) and neovessels at the
angle of the AC cause secondary glaucoma (100-days
glaucoma) as it usually occurs 100 days after the onset
of the vein occlusion.
7. Retina
1. Medical and cardiovascular evaluation to detect and
control the cause for thrombosis (eg. hypertension
and diabetes).
2. After resolution of hemorrhages, fluorescein
angiography is performed to detect ischemia,
macular edema and neovascularization.
3. Antiplatelet aggregation medication like aspirin 75 mg
/ day.
Management:
8. Retina
4. Argon laser photocoagulation: PRP in ischemic cases &focal
in macular edema.
5. Intravitreal injections:
A. Intravitreal injection of Triamcinolone (steroid).
B. Intravitreal injection of anti VEGF (vascular endothelial
growth factors).
6. Neovascular glaucoma: Is difficult to control and may require:
i. Cyclocryotherapy.
ii. Insertion of a valve as Ahmed valve or Molteno tube.
9. Branch Retinal Vein Occlusion
Retina
Definition:
Occlusion of one of the branches of the central retinal
vein. If this branch is more peripheral, vision is not
impaired. If the occluded branch is central, macular
edema is extensive and vision is impaired.
Ophthalmoscopic picture:
The occluded branch is dilated and tortuous, with
hemorrhages along the course of the occluded vein.
11. Retina
Retinal artery occlusion is mainly caused by emboli
reaching the retinal circulation via the ophthalmic artery. Since
it is an end artery and has no collaterals, occlusion results in
irreversible ischemic infarction of the retina.
Etiology:
1. Embolism.
2. Thrombosis following atherosclerosis.
3. Spasm of the central retinal artery.
4. Arteritis.
5. Sudden raised intraocular pressure.
12. Retina
Central retinal artery occlusion (CRAO)
Central retinal artery occlusion is an ocular emergency
resulting in sudden painless loss of vision in few hours.
Symptoms:
Sudden painless loss of vision.
Signs:
1. Normal external appearance of the eye.
2. Pupil: The pupil is dilated with loss of the direct light reflex
(RAPD) and preservation of the consensual.
3. Severe impairment of the visual acuity (up to no PL) .
13. Retina
Ophthalmoscopy
1. Retinal arteries: Attenuated (narrowed).
2. Retinal veins: blood is dark and segmented.
3. Central retina is milky white due to coagulative necrosis of
the inner retinal layers.
4. Macula: Cherry red spot: The fovea receives its supply from
the intact choriocapillaris, thus retaining its red color
against the rest of the retina which is milky.
5. Consecutive optic atrophy is the end stage.
14. Retina
1. Death of the inner half of the retina supplied by the
CRA occurs in 5-20 minutes. It is irreversible.
2. The central vision may sometimes be preserved due
to the presence of a cilioretinal artery (in 15% of the
population), arising from the posterior ciliary arteries,
which supplies the macular area.
Fate:
15. Retina
Branch occlusion is most commonly caused by emboli. Only
one or two of the branches of the central retinal artery are
occluded.
Ophthalmoscopy
A white area of infarction is seen along the course of the
occluded artery. It is associated with a field defect
corresponding to the area of infarction.
16. Management of Arterial Occlusions:
Retina
Treatment should start immediately. The rationale of
treatment is to lower the intraocular pressure and dilate
the artery to eliminate the obstruction. The prognosis is
bad, but all patients should be treated as an emergency:
17. 1. The patient should lie flat.
2. An attempt is made to restore blood flow in central retinal artery by:
a. Intravenous Acetazolamide 500 mg to lower IOP.
b. Intra venous Streptokinase.
c. Inhalation of carbogen mixture of 5% carbon dioxide and 95% oxygen.
d. Inhalation of amyl nitrite.
e. Ocular massage to lower the intraocular pressure (IOP).
f. Anterior chamber paracentesis.
3. Search for the cause as it may be due to a life-threatening disease as
cardiovascular disease.
Prognosis:
The prognosis is very poor.
Retina
18. III. Retinal Detachment (RD)
Retina
Types:
There are two main types:
A.Primary or rhegmatogenous RD:
Caused by a retinal break, which permits fluid, derived
from the liquefied vitreous to gain access to the subretinal
space (subretinal fluid " SRF") separating the sensory
retina (inner retinal layer) from the retinal pigment
epithelium (RPE, outer retinal layer) by subretinal fluid
(SRF).
19. Retina
II. Secondary or non-rhegmatogenous RD:
Not caused by a retinal break. It has two types.
A. Tractional:
In which the sensory retina is pulled away from the
RPE by contracting fibrous tissue in the vitreous
(vitreoretinal traction), e.g. proliferative stage of diabetic
retinopathy.
20. Retina
B. Exudative:
In which the retina is pushed off the choroid caused by
eg exudative choroiditis, toxemia or tumours as
malignant melanoma or hemangioma.
22. Risk Factors:
1. High myopia.
2. Aphakia.
3. Trauma (blunt or perforating).
4. Family history of RD or history of RD in the fellow
eye.
Retina
23. Clinical Picture:
Retina
Symptoms:
1. Flashes of light (photopsia).
2. Floaters (musca volitantes).
3. Visual field defect: It is perceived by the patient as a black
curtain in the opposite direction of retinal detachment.
4. Loss (failure) of central vision: due to (foveal detachment).
24. 1. Visual acuity: Depends on whether the fovea is involved and
on the extent of RD. In total RD, vision is usually hand
movement (HM).
2. The intraocular pressure is usually lower by about 5 mmHg
as compared to the normal eye. This is caused by rapid
absorption of SRF by the choroid.
3. Red reflex is grey.
4. Fundus examination reveals:
Retina
Signs:
a. Retinal break(s).
b. The subretinal fluid gives the retinal surface a wavy appearance.
25. Tractional Retinal Detachment
Retina
The main causes of tractional RD are:
1. Proliferative diabetic retinopathy (most common).
2. CRV thrombosis (ischemic type).
3. Retinopathy of Prematurity (ROP).
4. Proliferative sickle cell retinopathy.
5. Penetrating posterior segment trauma.
26. Retina
Exudative Retinal Detachment
1.Choroidal tumors such as melanoma, hemangioma
and metastases.
2. Intraocular inflammation such as choroiditis and
posterior scleritis.
3. Subretinal (choroidal) neovascularization.
4. Systemic causes such as severe hypertension,
toxemia of pregnancy and renal failure.
27. Retina
Investigation of a case of retinal detachment:
Ultrasonography:
Management of Rhegmatogenous retinal detachment:
Prophylactic treatment:
Indications:
Breaks or peripheral retinal degenerations in flat retina (no
RD).
Treatment Modalities:
The retinal tear is surrounded with either:
1. Argon laser photocoagulation.
2. Cryo applications.
28. Conventional retinal surgery(retinopexy)
Principle: It is extraocular surgery:
1. Localization of retinal break(s).
2. Seal the retinal break(s) by cryo or diathermy.
3. Scleral Buckling: Creation of inward indentation
of the sclera.
Retina
29. Pars Plana Vitrectomy:
Principle:
Vitrectomy is a microsurgical procedure,
designed to remove the vitreous gel in order to
gain access to a diseased retina in severe cases
of retinal detachment.
Retina
40. 38- What do the symptoms of localized upper nasal
retinal detachment include?
A)Ocular pain
B)Photophobia
C)Lower temporal field defect
D)Upper nasal field defect
E)Lower nasal field defect
41. 38- What do the symptoms of localized upper nasal
retinal detachment include?
A)Ocular pain
B)Photophobia
C)Lower temporal field defect
D)Upper nasal field defect
E)Lower nasal field defect
42. 78. Which is mostly associated with cherry red spot?
A)Central retinal artery occlusion.
B)Central retinal vein thrombosis.
C)Retinal detachment.
D)Branch retinal vein thrombosis.
E)Retinitis pigmntosa.
43. 78. Which is mostly associated with cherry red spot?
A)Central retinal artery occlusion.
B)Central retinal vein thrombosis.
C)Retinal detachment.
D)Branch retinal vein thrombosis.
E)Retinitis pigmntosa.
44. 118.Where does fluid accumulate in retinal
detachment?
A)Between outer plexhform layer and inner nuclear layer
B)Between neurosensory retina and layer of retinal
pigment epithelium
C)Between Nerve fiber layer and rest of retina
D)Between retinal pigment epithelium and rest of the retina
E)Between the vitreous and retina
45. 118.Where does fluid accumulate in retinal
detachment?
A)Between outer plexhform layer and inner nuclear layer
B)Between neurosensory retina and layer of retinal
pigment epithelium
C)Between Nerve fiber layer and rest of retina
D)Between retinal pigment epithelium and rest of the retina
E)Between the vitreous and retina
46. 125.Which of the followings is manifested by occlusion
of the lower nasal branch of the central retinal
artery?
A)Lower nasal sector field defect.
B)Upper nasal sector field defect.
C)Upper temporal field defect.
D)Lower temporal field defect.
E)nasal hemianopia
47. 125.Which of the followings is manifested by occlusion
of the lower nasal branch of the central retinal
artery?
A)Lower nasal sector field defect.
B)Upper nasal sector field defect.
C)Upper temporal field defect.
D)Lower temporal field defect.
E)nasal hemianopia
48. 178.What is the cause of rhegmatogenous retinal
detachment?
A)Tumour
B)Vitreous heamorrhage.
C)retinal break.
D)Proliferative diabetic retinopathy.
E)Choridal exudation
49. 178.What is the cause of rhegmatogenous retinal
detachment?
A)Tumour
B)Vitreous heamorrhage.
C)retinal break.
D)Proliferative diabetic retinopathy.
E)Choridal exudation