6-RETINA

Retina

Anatomy of the Retina

The Ten Layers of the Retina

1. Pigment epithelium layer2. Layer of rods and cones3. External limiting membrane 4. Outer nuclear layer5. Outer plexiform layer6. Inner nuclear layer7. Inner plexiform layer8. Ganglion cell layer9. Nerve fibre layer10.Internal limiting membrane

Symptoms in retinal diseases Night blindness Peripheral visual disturbance Central visual disturbance Color visual disturbance Metamorphopsia Micropsia Macropsia Photopsia Muscae volitantes (floaters) Without symptoms

Examinations Visual Acuity Dark Adaptation Color vision (Ishihara) Visual field :

confrontation test Goldmann perimetry Bjerrum tangent screen Octopus perimetry

Ophthalmoscopy direct ophthalmoscopy indirect ophthalmoscopy biomicroscopy + contact lens/ Hruby lens/ +90 D lens

DIRECTOPHTHALMOSCOPY

Fundus Reflex

Lens Opacity

External Light

INDIRECTOPHTHAL-MOSCOPY

DIRECT

INDIRECT

Specific Examinations

Fundus fluorescein angiography (FFA)Ultrasonography (USG)Electroretinography

FundusFluoresceinAngiography(FFA)

ULTRASONOGRAPHYof the NORMAL EYE

Diseases of the retinaCongenital anomaliesTrauma InflammationRetinal detachmentVascular disordersDegenerationNeoplasma

Retinal diseases to be discussed

Retinal detachment (ablatio retina)Retinal artery occlusionRetinal vein occlusionDiabetic retinopathyHypertensive retinopathyRetinitis pigmentosa

Retinal Detachment= ablatio retina

separatio retinae

A condition where the sensoric retinal

layer seperates from the retinal pigment epithelium layer (RPE)

Retinal Detachment

Classification based on pathogenesis : Rhegmatogenous RD

Break/tear in the retina (degeneration/ trauma) fluid from the vitreus cavity enters sub-retina retina detached

Nonrhegmatogenous RDProcess behind retina (tumor/

inflammation) subretinal fluid retina detached

Tractional RDFibrosis in vitreus (bleeding/inflammation) retinal traction retina detached

Retinal Detachment

Subjective symptoms Photopsia, floaters

due to retinal traction, vitreous bleeding Dark shadow/curtain

starts peripherally Reduced Vision

macular involvement or vitreous bleeding Metamorphopsia

macular involvement (detached)

Retinal Detachment

Objective signs Low IOP Relatively calm anterior segment Funduscopy

Detached retina greyish in color, elevated towards the vitreous cavity, vessels also elevated, surface often multi-lobulated

Retinal Tears

Cryo/ LaserProphylaxis

Retinal Detachment

Retinal DetachmentTherapy

Rhegmatogenous

Tractional Nonrhegmatogenous towards primary d. Surgical objectives

close the tear remove subretinal fluid remove vitreous traction

Surgery(Retinal repositioning)

Retinal Artery OcclusionA condition where the retinal artery is

occluded by an embolusSymptom: sudden visual loss without painTwo types :

Central (CRAO) - occlusion behind the lamina cribrosa

Branch (BRAO) - occlusion in front of lamina cribrosa

Retinal Artery Occlusion

Causes :ArteriosclerosisHypertensionCarotid arterial diseaseDiabetes mellitusValvular heart diseaseOthers: oral contraception, trauma,

coagulopathy, toxoplasmosis, etc.

Retinal Arterial Occlusion

Symptoms and signs:Sudden blurred vision (HM - LP)Calm anterior segmentFunduscopy

‘cherry-red spot’ (greyish pale retina except at the fovea)

small arteries, uneven caliber small veins, segmental


Branch RAO If macula not involved, vision relatively stable Retina pale only at the involved area A/v changes only at the occluded branchComplications: Papil atrophy NVI + NVGPrognosis: Poor. Visual recovery only if : 1. Occlusion overcome

within 1-2 hours after onset, 2. Occlusion temporary (spasm), 3. Cilioretinal artery present

BRAO

CRAO


Therapy: The aim of treatment is to quickly recover the

arterial circulation by lowering the IOP : paracentesis (AH aspirated 0.15 - 0.2 cc) Acetazolamide (Diamox) 500 mg. i.v. digital massage of eyeball inhalation of 95% O2 - 5% CO2 mixture

Look for cause consult Internal Medicine

Retinal Venous OcclusionSimilar to RAO, painless sudden loss of

vision as presenting symptom Two types:

central (CRVO) occlusion behind lamina cribrosa

branch (BRVO) occlusion in front of lamina cribrosa

RVO 4-5 times more often than RAO

Retinal Venous Occlusion

Causes : hypertension & arteriosclerosis (60%)

Common adventitial sheath at a-v crossing.

Sclerosis --> vein compressed --> slowed flow --> thrombus --> occlusion

open angle glaucoma (40-70%) hyperviscosity (polycythemia, hyperli-pidemia,

leukemia, etc) thromblophlebitis etc.


Symptoms and signs : sudden loss of vision calm anterior segment funduscopy :

dilated and tortuous vein edema, hemorrhage, soft exudate

Complication : NVG

30-35% of CRVO, 1-3 months after onset

CRVO

BRVO


Branch RVO : NVG seldom nasal branch --> no visual disturbance

Prognosis : without NVG --> edema, hemorrhage, exudate

slowly absorbed Therapy :

medical therapy of no benefit laser photocoagulation look for cause --> consult Internal Medicine

Diabetic RetinopathyDR is a retinal abnormality in a diabetic

due to microangiopathy Almost always bilateral although the

stages may be different incidence increased with duration of

DM : > 20 years 50% retinopathy > 30 years 80% more

Diabetic Retinopathy

Juvenile onset DM : delayed onset of DR.

Mature onset DM (age > 40 yrs) : onset sooner

Good metabolic control will delay the onset of DR

Main cause of new blindness in the US


Signs : microaneurysm retinal hemorrhage hard exudate soft exudate retinal edema collateral vessels (IRMA-IntraRetinal Microvasular

Abnormalities) venous beading CNPA (Capillary Non Perfusion Area) neovascularization & gliosis


Complications : vitreous hemorrhage tractional retinal detachment

Classification : nonproliferative (“background”) = NPDR proliferative = PDR diabetic macular edema = DME


NPDR early : signs 1 to 8 severe = preproliferative

PDR early : + sign 9 severe : + complications

Mild NPDR

Photo

FFA

Severe NPDR

Venous Beading

PDR

NVD

Severe PDR


Therapy metabolic control laser photocoagulation

indicated in severe NPDR early PDR DME

vitrectomy and retinal repositioning in Vitreous Hemorrhage and Retinal

Detachment complications

PRP PRP

FOCAL

PARS PLANA VITRECTOMY

Hypertensive Retinopathy

Changes in the retina of a hypertensive patient is due to hypertension and arteriosclerosis

changes due to hypertension : arteriole attenuation focal constriction/spasm hemorrhage and exudate papil edema

changes due to arteriosclerosis : changes in arteriole light reflex changes in a-v crossing

Hipertensive Retinopathy

Changes due to hypertension : arteriole attenuation

normal A:V ratio 2:3 or 3:4 attenuation < 3:4 (e.g. 1:2, 1:3)

focal constriction hemorrhage hard exudate soft exudate papil edema


Changes due to arteriosclerosis changes in arteriole light reflex changes in a-v crossing

SCHEIE classification(1953) 5 stages of hypertension and 5 stages of

arteriosclerosis are used

Attenuation

Focal Spasm

Venous Indentation

HypertensiveRetinopathy

HypertensiveRetinopathy

Papil Edema

CWSHemorrhage

SCHEIE classification

Hypertension Arteriosclerosis

Attenuation FocalSpasm

Hemorrhage Exudate PapilEdema

Light reflex

A-v crossingGrade

0

1

2

3

4

3 : 4

1 : 2

1 : 3

1 : 4

soft thread

1 : 1

1 : 1

2 : 3

1 : 3

distaloccl.

(-)

(-)

(-)

(+)

(+)

(-)

(-)

(-)

(+)

(+)

(-)

(-)

(-)

(-)

(+)

Yellow line

Widened

Copper

Silver

Fibrous thread

N

V.Inden

V.Inden

Dist dilat

Similar to 3

SCHEIE Classification

Hypertension Arteriosclerosis

0 0

Grade 1 Grade 1

Grade 2 Grade 2

Grade 3 Grade 3

Grade 4 Grade 4


Therapy : toward the hypertension hypertensive signs may disappear;

sclerotic signs persist papil edema, focal constriction quickly

disappear hemorrhage, soft exudate disappear within

several weeks-months hard exudate disappear within 4-6 months or

more

Retinitis PigmentosaA hereditary disease in which a

pigmentary degeneration of the retina occurs

Characteristically there is a progressive degeneration of the photoreceptors and RPE

most severe if X-linked recessive, least severe if autosomal dominant

Retinitis Pigmentosa

Subjective symptoms : Nightblindness Gradual reduction of visual acuity up to

less than 6/60 within 4 - 10 years. In X-linked this occurs usually earlier (reading disturbance at age 20, blindness at age 40)

often accompanied by hearing disturbance


Funduscopy : attenuation of retinal vessels in the midperiphery bone-specule pigmentation esp.

along vessels; retina slightly dirty grey in color Perimetry :

annular scotoma Therapy :

untreatable low vision aids (LVA) genetic counseling

6-RETINA

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