Post on 16-Jan-2017
VASCULAR DISORDERS OF RETINA
BY:
HARIS KHANROLL # 100
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.
LANDMARKS OF RETINA1. Optic Disc2. Retinal Blood
Vessels3. Area centralis with
fovea and foveola4. Peripheral retina
and ora serrata5. Thickest near the
optic disc6. Thin towards the
peripheral
MICROSCOPIC STRUCTURE
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.
•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.
VASCULAR DISORDERS OF RETINA
1. DIABETIC RETINOPATHY2. HYPERTENSIVE RETINOPATHY
3. RETINAL VEIN OCCLUSION4. RETINAL ARTERY OCCLUSION
5. RETINOPATHY OF PREMATURITY
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
RISK FACTORS• Age at diagnosis of diabetes• Duration• Poor control of diabetes• Pregnancy• Hypertension• Nephropathy• Hyperlipidemia• Obesity• Anemia• Smoking• Cataract surgery
PATHOGENESISMICROVASCULAR LEAKAGE1. LOSS OF PERICYTES2. MICRO ANEURYSM3. BLOOD RETINAL BARRIER
BREAKDOWN
IT CAUSES4. RETINAL OEDEMA5. HARD EXUDATE6. RETINAL HEMORRHAGES
• SUPERFICIAL(FLAME SHAPED)
• DEEP(DOT AND BLOT)
MICROVASCULAR OCCLUSION1. THICKENING OF BASEMENT
MEMBRANE2. ENDOTHELIAL DAMAGE3. STICKNESS AND AGGREGATION OF
PLATELETS4. FIBRINOLYTIC SYSTEM IS DEFECTIVE5. RED CELL AGGREGATION6. DEFECTIVE OXYGEN TRANSPORT
IT CAUSES7. RETINAL ISCAEMIA(COTTON WOOL
SPOTS)8. NEOVASCULARIZATION ON THE
SURFACE OF RETINA,OPTIC NERVE HEAD AND IRIS(RUBEOSIS IRIDIS)
9. ARTERIO VENOUS SHUNTS
SIGNS1. BACKGROUND DIABETIC RETINOPATHY2. PREPROLIFERATIVE STAGE3. PROLIFERATIVE STAGE4. DIABETIC MACULOPATHY5. ADVANCED STAGE
BACKGROUND DIABETIC RETINOPATHY
1. MICROANEURYSMS
MICRO ANEURYSMS
2. HAEMORRHAGES
1. FLAMED SHAPED HAEMORRHAGES
2. DOT AND BLOT HAEMORRAGES
3. HARD EXUDATES• LOCATED
BETWEEN INNER PLEXIFORM AND INNER LAYER OF RETIINA
• COMPOSED OF PLASMA PROTEINS AND LIPID
• YELLOW WAXY APPEARANCE WITH DISTINCT MARGINS
4. RETINAL EDEMAIT CAUSES THICKENING OF RETINA AND GIVES CYSTOID APPEARANCE TO RETINA
PREPROLIFERATIVE CHANGES
1. VASCULAR CHANGES• VENOUS CHANGES IN THE FORM OF
BEADING,LOOPING AND SAUSAGE LIKE SEGMENTATION
• ARTERIOLES BECOME NARROW
Retinal arteriole obliterationVenous Segmentation
Venous BeadingVenous Loop
2. COTTON WOOL SPOTS
APPEAR AS WHITISH,GREY AREAS WITH INDISTINCT MARGINS
3.DARK BLOT HAEMORRHAGETHEY REPRESENT HAEMORRHAGIC RETINAL INFARCTS
INTRA RETINAL MICROVASCULAR ABNORMALITIES
PROLIFERATIVE DIABETIC RETINOPATHY NEO
VASCULARIZATION : DISC
NEW VESSELS GROW OR
PROLIFERATE ON THE OPTIC NERVE
HEAD
2. NEO VASCULARIZATION
ELSEWHERE:NEW VESSELS PROLIFERATE
ALONG COURSE OF INTERNAL
TEMPORAL VASCULAR
ARCADES OR OTHER AREAS OF
RETINA
ADVANCED DIABETIC EYE DISEASE
• Pre retinal hemorrhage
• Vitreous hemorrhage
• Traction RD• Rubeosis
Iridis• Neovascular
Glaucoma
DIABETIC MACULOPATHYCAUSES1. OEDEMA2. HARD EXUDATE3. MACULAR
HAEMORRHAGE4. MACULAR ISCHAEMIA5. PRE MACULAR
MEMBRANE FORMATION
6. MACULAR TRACTION OR DETACHMENT
CLINICAL TYPES1. FOCAL EXUDATIVE2. DIFFUSED EXUDATIVE3. ISCHAEMIC4. MIXED MACULOPATHY
DIAGNOSIS1. 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
TREATMENTMEDICAL1. CONTROL OF RISK FACTORS
• DIABETES MELLITUS• HYPERTENSION,ANAEMIS,NEPHROPATHY,HYPERLIPI
DEMIA2. ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR3. INTRAVITREAL STEROIDS ARE USEFUL TO REDUCE THE MACULAR OEDEMA (INTRAVITREAL INJECTION OF TRIAMCINOLONE)
LASER PHOTOCOAGULATIONOBJECTIVES1. 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
TYPES1. FOCAL TREATMENT
FOR FOCAL MACULAR OEDEMA
2. GIRD TREATMENT FOR DIFFUSE MACULAR OEDEMA
3. PANRETINAL PHOTOCOAGULATION
SURGERYPARS PLANA VITRECTOMY IS INDICATED FOR:1. DENSE PERSISTENT
VITREOUS HAEMORRHAGE2. TRACTIONAL RETINAL
DETACHMENT3. EPIRETINAL MEMBRANES
HYPERTENSIVE RETINOPATHYDEFINITION
HYPERTENSIVE RETINOPATHY IS A RETINAL VASCULAR DAMAGE CAUSED BY
HYPERTENSION.
Pathophysiology
Systermic chronic hypertension
Arteriosclerosis and
atherosclerosis predominates
Narrowing of retinal arterioles Retinal Ischaemia
HypoxiaIncreased capillary
permeability
Focal Retinal Oedema, retinal
haemorrhage,cotton wool spots, hard exudates
1.
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.
Retinal arteriolar narrowing due to thickening and opacification of arteriolar walls (copper wiring) caused by hypertensive arteriosclerosis. Image also
shows macular edema.
Classification• Keith-Wagener-Barker classification
Grade DescriptionGrade 1 Slight narrowing, sclerosis, and tortuosity of the retinal arterioles; mild,
asymptomatic hypertensionGrade 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
Modified Scheie classification
Grade 0 - No changes
Grade 1 - Barely detectable arterial narrowing
Grade 2 - Obvious arterial narrowing with focal irregularities
Grade 3 - Grade 2 plus retinal hemorrhages and/or exudates
Grade 4 - Grade 3 plus disc swelling
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 occlusiono Branch Retinal vein occlusion
• Etiology and Risk Factors:o Age of age of above 50 yearso Systemic diseases like hyperlipidemia, Diabetes, Chronic
Renal Failureo Chronic Open Angle Glaucoma
Retinal Vein Occlusion• Clinical Presentation:
o Sudden painless loss of visiono Persistent decreased central vision
• Clinical Examination:o Visual Acuity- Severe visual loss, up to 20/200o Intra Ocular Pressure- Raisedo Fundus Examination- dilated, tortuous veins, retinal and
macular edema, flame shaped hemorrhages, and cotton wool spots
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)
• 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.
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
Retinal Vein Occlusion• Investigations:
o Fluorescein Angiographyo ECGo Blood CPo ESRo Blood Glucose level
• Complications:o Chronic Macular Edemao Conversion from Non-Ischemic to Ischemic typeo Retinal Neovascularizationo Neovascular Glaucoma
Retinal Vein Occlusion• Treatment:
o Macular Laser Photocoagulationo Intra Vitreal injections anti-VEGF and steroidso Intra Vitreal triamcinolone injections
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 Occlusiono Branch Retinal Artery Occlusion
• Etiology:o Thrombosis due to atherosclerosiso Embolismo Raised Intra Ocular Pressureo Giant Cell Arteritiso Angiospasm- Retinal Migraine
Clinical manifestation
Symptoms
Signs
Sudden painless vision lose of one eye
Direct light reflex disappear, indirect light reflex normal
Retinal edema、 cherry-red spotRetina artery narrow,mild hemorrhage
CENTRAL RETINAL ARTERY
OCCLUSION• RETINAL OEDEMA
• CHERRY RED SPOTS• RETINAL ARTERY
NARROW • MILD
HAEMORRHAGE• WHITISH
APPEARANCE OF RETINA
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.
Retinal Artery Occlusion
• Treatment:o Intraocular pressure lowered immediately by anterior
chamber paracentasis or I.V Acetazolamideo Inhaled oxygen and carbon dioxide mixture to improve
oxygen delivery to retinao Thrombolytic therapy
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 weighto Exposure to high concentrations of oxygeno Premature birth
• Pathology:o THE TEMPORAL RETINAL VASCULARIZATION IS
COMPLETED 1 MONTH AFTER BIRTHo TOXIC LEVEL OF OXYGEN INTERFERES WITH
REVASCULARIZATION BY DAMAGING THE ENDOTHELIUM AND OBLITERATING NEWLY FORMED CAPILLARIES.
Retinopathy Of Prematurity
Stage 1- Changes at junction of vascular and avascular retina as demarcation line
Retinopathy Of Prematurity
Stage 2- Formation of distinct ridge
Retinopathy Of Prematurity
Stage 3- Extra retinal fibrovascular proliferation
Retinopathy Of Prematurity
Stage 4- Severe retinal detachment
Retinopathy Of Prematurity
Stage 5- Total retinal detachment seen as whitish mass (leukocoria) behind iris
Retinopathy Of Prematurity
• Treatment:o Peripheral retinal laser in stage 2o Ablation of avascular retina in stage 3o Vitreotomy in stage 4 & 5