3. ANATOMY OF RETINA
The retina is a thin,
semitransparent, multilayered
sheet of neural tissue that lines
the inner aspect of the posterior
two-thirds of the wall of the
globe.
4. LANDMARKS OF RETINA
1. Optic Disc
2. Retinal Blood
Vessels
3. Area centralis with
fovea and foveola
4. Peripheral retina
and ora serrata
5. Thickest near the
optic disc
6. Thin towards the
peripheral
6. BLOOD SUPPLY OF THE RETINA:
•Outer 4 layers of retina is supplied by (till outer nuclear layer)
choriocapillaries.
•The inner six layers gets its supply from central retinal artery which
is a branch of ophthalmic artery.
•The outer plexiform layer gets partly by both the above arteries.
•The fovea is avascular and is mainly supplied by choriocapillaries.
•The inner portion of the retina is perfused by branches of the central
retinal artery.
•In 30% of eyes ,a cilioretinal artery,branching from the ciliary
circulation ,supplies part of inner retina mainly The Macula Region.
•The retinal blood vessels maintain the inner blood-retinal barrier.This
physiological barrier is due to single layer of non-fenestrated
endothelial cells,whose tight junctions are impervious to tracer
substances such as fluorescein.
7.
8. •Retinal blood vessels lack an internal elastic lamina & a
continuous layer of smooth muscle cells.
•The retinal arteries are end arteries & have no
anastomoses.The only place where the retinal system
anastomoses is in the neighbourhood of lamina cribrosa.
•The veins of the retina unite to form Central retinal vein at the
disc, which follows the corresponding artery.
•The terminal fundus arterioles bend sharply and dip almost
vertically into the retina.
•In most of the Extramacular fundus- two retianal capillary
networks- a superficial and a deep.
•In parafoveal zone it is well developed and in 3 layers.
•A capillary free zone of 500miceo metre diameter in foveal
zone- FAZ.
9. VASCULAR DISORDERS OF
RETINA
1.DIABETIC RETINOPATHY
2.HYPERTENSIVE RETINOPATHY
3.RETINAL VEIN OCCLUSION
4.RETINAL ARTERY OCCLUSION
5.RETINOPATHY OF PREMATURITY
10. DIABETIC RETINOPATHY
• Diabetic retinopathy is a disorder of the retinal
vessels that eventually develops to some
degree in nearly all patients with long-
standing diabetes mellitus.
• Most Common cause of bilateral severe visual
loss in working age group in US
11. RISK FACTORS
• Age at diagnosis of diabetes
• Duration
• Poor control of diabetes
• Pregnancy
• Hypertension
• Nephropathy
• Hyperlipidemia
• Obesity
• Anemia
• Smoking
• Cataract surgery
12. PATHOGENESIS
MICROVASCULAR LEAKAGE
1. LOSS OF PERICYTES
2. MICRO ANEURYSM
3. BLOOD RETINAL BARRIER
BREAKDOWN
IT CAUSES
1. RETINAL OEDEMA
2. HARD EXUDATE
3. RETINAL HEMORRHAGES
• SUPERFICIAL(FLAME
SHAPED)
• DEEP(DOT AND BLOT)
MICROVASCULAR OCCLUSION
1. THICKENING OF BASEMENT
MEMBRANE
2. ENDOTHELIAL DAMAGE
3. STICKNESS AND AGGREGATION OF
PLATELETS
4. FIBRINOLYTIC SYSTEM IS DEFECTIVE
5. RED CELL AGGREGATION
6. DEFECTIVE OXYGEN TRANSPORT
IT CAUSES
1. RETINAL ISCAEMIA(COTTON WOOL
SPOTS)
2. NEOVASCULARIZATION ON THE
SURFACE OF RETINA,OPTIC NERVE
HEAD AND IRIS(RUBEOSIS IRIDIS)
3. ARTERIO VENOUS SHUNTS
17. 3. HARD EXUDATES
• LOCATED
BETWEEN INNER
PLEXIFORM AND
INNER LAYER OF
RETIINA
• COMPOSED OF
PLASMA PROTEINS
AND LIPID
• YELLOW WAXY
APPEARANCE WITH
DISTINCT MARGINS
19. PREPROLIFERATIVE CHANGES
1. VASCULAR CHANGES
• VENOUS CHANGES IN THE FORM OF
BEADING,LOOPING AND SAUSAGE LIKE
SEGMENTATION
• ARTERIOLES BECOME NARROW
28. DIAGNOSIS
1. FUNDUS EXAMINATION WITH
• DIRECT OPHTHALMOSCOPE
• INDIRECT OPHTHALMOSCOPE
• SLIT LAMP BIMICROSCOPY WITH CONTACT LENS
AND NON CONTACT LENS
2. FUNDUS FLUORESCEIN ANGIOGRAPHY FOR
ASSESSMENT OF:
• LEAKING AREAS
• OCCLUSION AREAS
3. OPTICAL COHERENCE TOMOGRAPHY IS USEFUL
TO ASSESS RETINAL OEDEMA
29. TREATMENT
MEDICAL
1. CONTROL OF RISK FACTORS
• DIABETES MELLITUS
• HYPERTENSION,ANAEMIS,NEPHROPATHY,HYPERLIPI
DEMIA
2. ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR
3. INTRAVITREAL STEROIDS ARE USEFUL TO REDUCE
THE MACULAR OEDEMA (INTRAVITREAL INJECTION OF
TRIAMCINOLONE)
30. LASER PHOTOCOAGULATION
OBJECTIVES
1. TO DESTROY THE HYPOXIC
RETINA ,STOP THE RELEASE
OF VASOFORMATIVE
SUBSTANCE AND CAUSE
INVOLUTION OF NEW VESSEL
2. TO DESTROY THE LEAKAGE
AREAS AND ENHANCE THE
ABSORPTION OF OEDEMA
AND EXUDATE
TYPES
1. FOCAL TREATMENT
FOR FOCAL MACULAR
OEDEMA
2. GIRD TREATMENT
FOR DIFFUSE
MACULAR OEDEMA
3. PANRETINAL
PHOTOCOAGULATION
31.
32. SURGERY
PARS PLANA VITRECTOMY IS
INDICATED FOR:
1. DENSE PERSISTENT
VITREOUS HAEMORRHAGE
2. TRACTIONAL RETINAL
DETACHMENT
3. EPIRETINAL MEMBRANES
36. 1. The cardinal funduscopic feature of malignant hypertension is disk swelling, which appears as
blurring and elevation of disk margins. The top image also shows a characteristic star-shaped
macular lesion caused by leaking retinal vessels; the bottom image also shows a characteristic
flame-shaped hemorrhage and dilated veins.
2. Moderate hypertensive retinopathy is characterized by thinned, straight arteries; intraretinal
hemorrhages; and yellow hard exudates (top). Cotton-wool spots (bottom) are an additional
feature of moderate hypertensive retinopathy. They are caused by focal axonal swelling of the
retinal nerve fiber layer as a result of small-vessel occlusion.
37. Retinal arteriolar narrowing due to thickening and opacification of arteriolar
walls (copper wiring) caused by hypertensive arteriosclerosis. Image also
shows macular edema.
38. Classification
• Keith-Wagener-Barker classification
Grade Description
Grade 1 Slight narrowing, sclerosis, and tortuosity of the retinal arterioles; mild,
asymptomatic hypertension
Grade 2 Definite narrowing, focal constriction, sclerosis, and AV nicking; blood
pressure is higher and sustained; few, if any, symptoms referable to blood
pressure
Grade 3 Retinopathy (cotton-wool patches, arteriolosclerosis, hemorrhages); blood
pressure is higher and more sustained; headaches, vertigo, and
nervousness; mild impairment of cardiac, cerebral, and renal function
Grade 4 Neuroretinal edema, including papilledema; Siegrist streaks, Elschnig
spots; blood pressure persistently elevated; headaches, asthenia, loss of
weight, dyspnea, and visual disturbances; impairment of cardiac, cerebral,
and renal function
41. Retinal Vein Occlusion
• Definition:
o It is a common vascular disorder characterized by retinal vein
occlusion resulting in edema and hemorrhages on retina in the
affected region with potential blinding complications
• Types:
o Central retinal vein occlusion
o Branch Retinal vein occlusion
• Etiology and Risk Factors:
o Age of age of above 50 years
o Systemic diseases like hyperlipidemia, Diabetes, Chronic Renal
Failure
o Chronic Open Angle Glaucoma
42. Retinal Vein Occlusion
• Clinical Presentation:
o Sudden painless loss of vision
o Persistent decreased central vision
• Clinical Examination:
o Visual Acuity- Severe visual loss, up to 20/200
o Intra Ocular Pressure- Raised
o Fundus Examination- dilated, tortuous veins, retinal and macular
edema, flame shaped hemorrhages, and cotton wool spots
43. Central retinal vein occlusion
Clinical manifestation
• Non-ischemic type
– Mild fundus change :
retinal hemorrhage and
tortuous vein
– Mild VA decrease
– capillary nonperfusion rare
– Visual field defect (retinal
hemorrhage)
44. • Ischemic type:
– More common
– Extensive retinal
hemorrhage and
tortuous vein,Multiple
cotton-wool spots
– Severe VA decrease
– Widespread capillary
nonperfusion, 60%
cases present iridal
neovascularization.
45. BRANCH RETINAL
VEIN OCCLUSION
• MORE COMMON THAN
CRVO
• OEDEMA AND
HAEMORRHAGE
LIMITED TO THE
AFFECTED VEIN
• VISSION AFFECTED
ONLY MACULAR AREA
IS INVOLVED
• SECONDARY
GLAUCOMA OCCURS
RARELY
• PROGNOSIS IS
REASONABLY GOOD
46. Retinal Vein Occlusion
• Investigations:
o Fluorescein Angiography
o ECG
o Blood CP
o ESR
o Blood Glucose level
• Complications:
o Chronic Macular Edema
o Conversion from Non-Ischemic to Ischemic type
o Retinal Neovascularization
o Neovascular Glaucoma
47. Retinal Vein Occlusion
• Treatment:
o Macular Laser Photocoagulation
o Intra Vitreal injections anti-VEGF and steroids
o Intra Vitreal triamcinolone injections
48. Retinal Artery Occlusion
• Definition:
o Vascular disorder of retina resulting in sudden painless loss of
vision, with antecedent transient visual loss
• Types:
o Central Retinal Artery Occlusion
o Branch Retinal Artery Occlusion
• Etiology:
o Thrombosis due to atherosclerosis
o Embolism
o Raised Intra Ocular Pressure
o Giant Cell Arteritis
o Angiospasm- Retinal Migraine
51. BRANCH
RETINAL
ARTERY
OCCLUSION
• DUE TO LODGMENT OF
EMBOLI AT
BIFURCATION OF
RETINAL ARTERY
• RETINAL DISTAL TO
OCCLUSION BECOMES
OEDEMATIOUS WITH
NARROWED
ARTERIOLES
• INVOLVED AREA
ATROPHIED CAUSING
SECTORIAL VISUAL
FIELD DEFFECT
PERMANANTLY.
52. Retinal Artery Occlusion
• Treatment:
o Intraocular pressure lowered immediately by anterior chamber
paracentasis or I.V Acetazolamide
o Inhaled oxygen and carbon dioxide mixture to improve oxygen
delivery to retina
o Thrombolytic therapy
53. Retinopathy Of Prematurity
• Definition:
o It is a bilateral vasoproliferative retinopathy occurring in
premature infants with low birth weight and exposed to high
concentration of oxygen
• Etiology and Risk Factors:
o Low birth weight
o Exposure to high concentrations of oxygen
o Premature birth
• Pathology:
o THE TEMPORAL RETINAL VASCULARIZATION IS
COMPLETED 1 MONTH AFTER BIRTH
o TOXIC LEVEL OF OXYGEN INTERFERES WITH
REVASCULARIZATION BY DAMAGING THE ENDOTHELIUM
AND OBLITERATING NEWLY FORMED CAPILLARIES.
59. Retinopathy Of Prematurity
• Treatment:
o Peripheral retinal laser in stage 2
o Ablation of avascular retina in stage 3
o Vitreotomy in stage 4 & 5