Download MBBS Ophthalmology PPT 51 Retinal Detachment Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Ophthalmology PPT 51 Retinal Detachment Lecture Notes


RETINAL DETACHMENT

Acknowledgement

? Photographs in this presentation are courtesy
of Dr.Freund. K. Bailey (The Retinal Atlas,2nd Ed.)
and
Dr.Brad Bowling (Kanski's Clinical Ophthalmology,
8thEd.)
Learning Objectives

At the end of the class, students shall be able to

? Define and classify the various types of retinal

detachments (R.D.)

? Understand the pathophysiology and signs and

symptoms of retinal detachments

? Have a basic understanding of the management
of various types of retinal detachments

What is the retina?

? Innermost coat of the eyeball.
? Thin, delicate, transparent membrane.
? Externally related to the choroid & sclera.
? Thickness

? Near optic disc ? 0.56 mm
? Equator ? 0.18 to 0.2 mm
? Ora-serrata ? 0.1 mm
? Thinnest at Fovea.







Normal Fundus


Layers of the retina

1. Retinal Pigment Epithelium

2. Layer of Rods & Cones

3. External Limiting Membrane

4. Outer Nuclear Layer

5. Outer Plexiform Layer

6. Inner Nuclear Layer

7. Inner Plexiform Layer

8. Ganglion Cel Layer

9. Nerve Fibre Layer

10.Internal Limiting Membrane

RETINAL DETACHMENT (RD)

1. Definitions and classifications

? Retinal breaks

? Retinal detachment


Definition and classification

? Break - full-thickness defect in sensory retina

? Hole - caused by chronic retinal atrophy

? Tear - caused by dynamic vitreoretinal traction

Morphology of tears

a. Complete U-tear

d. Operculated

b. Linear

e. Dialysis

c. Incomplete L-shaped

DEFINITION

? RETINAL DETACHMENT (R.D.) is defined as the

separation of neurosensory retina (NSR) from

retinal pigment epithelium (RPE) caused by

breakdown of forces that attach the NSR to

RPE resulting in accumulation of sub retinal

fluid (SRF) in the potential space between the

NSR and RPE.


Retinal detachment (RD)

Separation of sensory retina from RPE by subretinal fluid (SRF)

Rhegmatogenous - caused by a

Non-rhegmatogenous - tractional or

retinal break

exudative

Classification

? Clinico-etiologically ? Three types of retinal
detachment
1. Rhegmatogenous(or primary) retinal

detachment

2. Tractional retinal detachment
3. Exudative retinal detachment


Classification-

Rhegmatogenous

Exudative

Tractional

Predisposing factors for RD

? Myopia
? Aphakia (& Pseudophakia)
? Trauma
? Retinal Degenerations
? PVD


Rhegmatogenous retinal detachment

? Is usually associated with a retinal break
(hole/tear)
? Sub retinal fluid(SRF) seeps and separates the

neurosensory retina from the retinal pigment

epithelium(RPE)

Indirect ophthalmoscopy

Condensing lenses

Technique

? The higher the power, the less the

? Keep lens parallel to patient's iris plane

magnification, the shorter the working

? Avoid tendency to move towards

distance , greater the field of view

patient
? Ask the patient to move eyes and head

into optimal positions for examination




Scleral indentation

Retinal breaks in detached Enhanced visualization of

retina without indentation breaks with indentation

Slitlamp biomicroscopy

Goldmann triple-mirror lens

View of peripheral fundus

? Equatorial mirror (largest and

?

oblong) - from 30 to equator

?Image is upside down

? Peripheral mirror (square) -

from equator to ora serrata

? Gonioscopic (smallest)


Predisposing peripheral degenerations

Typical lattice degeneration
? Present in about 8% of general population
? Present in about 40% of eyes with RD

Retina

Vitreous

? Spindle-shaped islands of retinal thinning

? Overlying vitreous liquefaction

? Network of white lines within islands

? Exaggerated attachments

? Variable associated RPE changes

around margin of lesion

? Smal round holes within lesions are common




Snail track degeneration

Sharply demarcated, frost-like bands Large round holes which carry

which are longer than lattice

high risk of RD

Indications for prophylaxis - presence of holes

White-without-pressure

Translucent grey appearance of retina

Occasional giant tear formation along

posterior margin of lesion

Indications for prophylaxis - giant tear in other eye
Why is normal retina attached?

? Vitreous tamponade
? Acid mucopolysaccharides (Bio glue)
? Hydrostatic pressure( Less pressure in the sub

retinal space)

? RPE Pump

Pathogenesis

? Retinal breaks are due to
dynamic vitreoretinal traction
and
predisposing retinal degeneration
? Degenerated fluid vitreous seeps through

retinal break and collects as SRF between

sensory retina and RPE leading to RD


Pathogenesis of rhegmatogenous RD

Two components for retinal break formation

? Acute posterior vitreous detachment (PVD)

? Predisposing peripheral retinal degeneration

Possible sequelae of acute PVD

Uncomplicated PVD (85%) Retinal tear formation and Avulsion of retinal vessel &

haemorrhage (10-15%)

haemorrhage (uncommon)

Clinical features

? Prodromal symptoms
Floaters (dark spots)
Photopsia (flashes of light)
? Symptoms of RD
Loss in the field of vision(Localised and relative

progressing to total loss)
Painless loss of vision(usually rapid) with

appearance of cloud/veil in front of affected eye


Signs of R.D.

? External examination: Usually normal
? Intra ocular pressure: Slightly lower or normal
? Pupils: Normal reaction or Relative Afferent

Pupillary Defect in extensive RD

? Plane mirror examination: Greyish reflex


Signs of R.D.

? Ophthalmoscopy: Indirect Ophthalmoscopy

with scleral indentation: Tobacco

dust(Shafer's sign)

? Retinal breaks
? Convex configuration with folds(corrugations)
? Loss of the choroidal pattern
? Retinal blood vessels - darker than in flat

retina

Fresh rhegmatogenous RD - signs

? Annual incidence - 1:10,000 of population
? Eventual y bilateral in 10%

? Convex, deep mobile elevation

? Loss of choroidal pattern

extending to ora serrata

? Retinal breaks

? Slightly opaque with dark blood vessels


Signs of old RD

? Retinal thinning (due to atrophy)
? Sub retinal demarcation line/high water mark
(due to RPE proliferation)
? Secondary intra retinal cysts

Longstanding rhegmatogenous RD - signs

? Frequently inferior with small holes

? Demarcation lines (high-water marks)

? Very thin retina

? Secondary intraretinal cysts
Investigations

? Ultrasonography confirms the diagnosis
especially when media is hazy.
? Visual field charting : scotomas

(relative/absolute)

? ERG: subnormal or absent

Complications

? Proliferative vitreo retinopathy(PVR)
? Complicated cataract
? Uveitis
? Phthisi bulbi




Proliferative vitreoretinopathy

Grade A (minimal)

Grade B (moderate)

Grade C (severe)

? Vitreous haze and

? Retinal wrinkling and

? Rigid retinal folds

tobacco dust

stiffness

? Vitreous condensations

? Rolled edges of tears

and strands

Differential diagnosis of RD

Degenerative retinoschisis Choroidal detachment Uveal effusion syndrome

? Frequently bilateral

? Associated with hypotony ? Idiopathic

? Smooth, thin and immobile ? Unilateral, brown, smooth, ? Rare, unilateral

? Occasionally breaks in one solid and immobile

? Combined choroidal

or both layers

? Ora serrata may be visible & exudative detachments
Aims of management of RD

? Seal/close retinal breaks with
photocoagulation or cryotherapy
(or diathermy ? Jules Gonin -Ignipuncture)

? Sub Retinal Fluid drainage : for immediate

apposition between sensory retina and RPE

(Not in all cases)

Aims of management of RD

? Maintain chorioretinal apposition/adhesion by
1. Scleral Buckling to provide external

tamponade

2. Pneumatic retinopexy
3. Pars plana vitrectomy (to relieve traction on

retina)


Technique of laser photocoagulation

Surround lesion with two rows of

Difficult for anterior lesions and if

confluent burns

media hazy

Technique of cryotherapy

? Surround lesion with single row of

cryo-applications

? Preferred for treatment of large

areas




Cryotherapy

While viewing with indirect ophthalmo-

Freeze break until sensory retina just

Scope indent sclera gently with

turns white

tip of cryoprobe

Drainage of subretinal fluid

Indications

? Difficulty in localizing break

? Immobile retina

? Longstanding RD

? Inferior RD

Technique

Complications

Haemorrhage

Retinal incarceration






Pneumatic retinopexy

Indications

RD with superior breaks

Technique

(a) Cryotherapy

(b) Gas injection

(c) Postoperative positioning

(d) Flat retina




Vitrectomy for giant tears

Unrolling of flap with light Completion of unrolling

Injection of silicone oil or

pipe and probe

heavy liquid

Vitrectomy for PVR

? Dissection of star folds and peeling of

membranes
? Injection of expanding gas or silicone oil


Tractional Retinal detachment

? Occurs due to mechanical pull/traction on the

retina by contraction of fibrous tissue in the

vitreous.

? Etiology
?Proliferative Diabetic Retinopathy (PDR)
?Penetrating posterior segment trauma
?Retinopathy of prematurity

Signs of tractional RD

?

? Concave, shallow immobile elevation

Slow progression and variable fibrosis

?

? Highest at sites of vitreoretinal traction

Does not extend to ora serrata


Vitrectomy for tractional RD

Release of circumferential Release of antero-

traction

posterior traction

Endophotocoagulation

Exudative Retinal detachment

? Occurs due to the retina being pushed away

by a neoplasm or fluid accumulation beneath

the retina following inflammatory or vascular

lesions.
Pathogenesis and Causes of Exudative RD

? Damage to RPE by subretinal disease
? Passage of fluid derived from choroid into subretinal space

1. Choroidal tumours

Primary

Metastatic

2. Intraocular inflammation

Harada's Disease

Posterior Scleritis

3. Intraocular inflammation

Toxemia of pregnancy

Hypoproteinemia

Pathogenesis and Causes of Exudative RD

4. Vascular
? CSR
? Coat's disease
5. Iatrogenic
? RD surgery

? Excessive retinal photocoagulation
6. Miscellaneous
? Choroidal neovascularization

? Uveal effusion syndrome

? Nanophthalmos


Signs of exudative RD

? Convex, smooth elevation

? Subretinal pigment (leopard spots)

? May be very mobile and deep with

after flattening

shifting fluid

Medical Management

? Inflammatory conditions

(such as scleritis and Vogt-Koyanagi-Harada syndrome)

anti-inflammatory agents.

? Tumors-

v External beam radiation therapy or brachytherapy with a

plaque may be used for choroidal melanoma.

v Metastatic lesions respond to chemotherapy or localized

radiation therapy.

v Choroidal hemangiomas may respond to laser

photocoagulation or plaque brachytherapy.

v Retinoblastomas may be shrunk with chemotherapy and

then treated local y with heat, laser, or cryotherapy.
Medical Management

? Infectious aetiologies -antibiotics.
? Exudative retinal detachments secondary to

chronic renal failure may have spontaneous

retinal reattachment following renal

transplant or renal dialysis.

? Anti-VEGF agents -Coats disease.

Surgical Management

? Conditions with vascular anomalies, such as

Coats disease-laser- cryotherapy

vitrectomy

? Congenital anomalies, such as optic pits or

colobomas

-vitrectomy and endolaser techniques.
Differences between types of RD

Rhegmatogenous Tractional

Exudative/serous

Hole/Break

Surface

+

- -

Convex,corugated Concave,

scalloped Convex,smoth

SRF shift

Height of RD

Rare

-- ShiftingSRF

Nevrreacheslens Shallow Mayreach/touch

Course

lens

Progresive/Static Progresive Waxes/wanes

Mayresolvebyitself

Management

Surgical

Surgical Medical/surgical

Conclusion

? Retinal Detachment is defined as the

separation of neurosensory retina (NSR) from

retinal pigment epithelium (RPE).

? It may be rhegmatogenous, tractional or

exudative.

? Is one of the causes of significant visual loss.
? Management is mainly surgical.

This post was last modified on 07 April 2022