Transcript Management of Retinal Degenerations and Retinal detachment

Management of
Retinal detachment
Dr. Vincent Yau-Wing Lee
Asia-Pacific Vitreo-retina Society
Types of Retinal detachment
1. Rhegmatogenous (RRD)
accumulation of subretinal fluid
via a retinal break
Types of Retinal detachment
2. Tractional (TRD)
vitreous or fibrovasuclar
membrane pulling up the retina,
DRM, ROP, Trauma etc
Types of Retinal detachment
3. Exudative
accumulation of subretinal fluid,
with the fluid being derived from
blood vessels of the retina, or
the choroid, or both
Tumor, uveitis, vascular lesion
Rhegmatogenous Retinal
detachment (RRD)
Retina Detachment
Neurosensory retina
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2.
3.
4.
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8.
9.
Photoreceptors of rods & cones
External limiting membrane
Outer nuclear layer
Outer plexiform layer
Inner nuclear layer
Inner plexiform layer
Ganglion cell layer
Nerve fiber layer
Internal limiting membrane
Retinal Pigmented Epithelium
(RPE)
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Rhegmatogenous retinal detachment
from the Greek word rhegma, which
means “a rent”
How does RRD happen?
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Understand the normal force keep the
retina attached.
Understand the relationship between PVD
and RD
Causes of RD other than PVD
Normal forces keep the retina attached
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hydrostatic pressure
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physiologic removal of subretinal fluid by RPE pump
elevated colloid osmotic pressure generated by the high
concentration of protein in choroidal tissue fluid
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Acid mucopolysaccharide in the subretinal space
(extracellular martix)
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photoreceptor–retinal pigment epithelium (RPE)
interaction
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molecular interaction between interdigitating RPE projections
and close conformation to the overlying photoreceptors
Relationship between PVD and RD
Schepens CL. The Vitreous and Vitreoretional Interface.
New York, Springer-Verlag, 1987
Consequence of PVD
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2
Uncomplicated, or
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4.
Retinal hole
Vitreous hemorrahage
Retinal tear
Retinal detachment
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4
Rhegmatogenous RD (RRD) Causes
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Posterior vitreous detachment
Peripheral fundus lesion
Myopia
Ocular surgery – cataract extraction
Trauma
Intraocular inflammation / infection
Syndromes
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Wagner-Jansen-Stickler Syndrome
Goldmann Favre Syndrome
Marfan’s Syndrome
Homocystinuria
Ehlers-Danlos Syndrome
Management of RRD
Pre op exam - Retinal drawing
The break through of retinal
detachment repair
First vitrectomy machine – one port
(Machemer,1970)
Scleral Buckle (Custodis,1949)
Modern 3 port vitrectomy system
(O’Malley,1972)
Goals of treatment for Retinal
Detachment
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Preservation of vision. In particular the
central vision
Relief of inward traction on the retina
Closure of all retinal breaks
Elimination of subretinal fluid
Relieve traction 1
Relieve traction 2
Relieve traction 3
Modern RD Repair
Basic concept:
Main Aim
External steps
Internal steps
Seal retinal break /
Relieve traction
Scleral Buckle
Intraocular gas /
silicone oil
Flatten retina
External drainage
Heavy liquid / Gas
fluid exchange
(Internal drainage)
Formation of
Retino-choroidal
adhesion
Cryotherapy
Endo-laser
Modern RD Repair
3 main Types of Surgery:
•
Pneumatic retinopexy
•
Scleral buckling
•
Pars plana vitrectomy
Pneumatic retinopexy
Main Aim
External steps
Internal steps
1. Seal retinal
break / Traction
relieve
Buckle
Intraocular gas
100%
2. Flatten retina
External drainage
Heavy liquid /
Gas fluid exchange
3. Formation of
Retino-choroidal
adhesion
Cryotherapy
Endolaser
Pneumatic retinopexy
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use of the flotation force and surface tension of an
intraocular gas bubble to cause temporary functional
closure of the retinal break and displace the break
towards the eye ball.
successful rate of 63 to 84%
when the retina fail to reattach by pneumatic
retinopexy, the patient can still proceed to scleral
buckling or pars plana vitrectomy procedures, and the
final reattachment rates were shown to be similar.
Advantage: mainly to minimize complications associated
with scleral buckling procedure.
Commonest reason for failure in pneumatic retinopexy
is missed break intraoperatively or new break
formations postoperatively (6-23%).
SM Saw. Acta Ophthalmologica Scandinavica, 2006
Pneumatic retinopexy
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Indication
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Contraindication
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retinal break equal to / smaller than 1 clock hours’ size
located within the superior 8 clock hours of the peripheral retina
with proliferative retinopathy grade C or above
Aphakic / pseudophakic eye (relative contraindication only)
The Retina Detachment Study Group: Pneumatic retinopexy: A multicenter randomized controlled
clinical trial comparing pneumatic retinopexy with scleral buckling. Ophthalmology 1989
Pneumatic retinopexy
Head posture postoperation for 12 to 18
hours a day for ~ 5 days.
Arrow for proper head
posture
Gas bubble as
tamponade
Gas property
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For Pneumatic retinopexy: 100% gas, 0.3 – 0.5 ml
Gas dynamic
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most rapid rate of volume
increase occurs within the
first 6 to 8 hours.
Sulfur hexafluoride
maximally expanded
volume by 24 to 48 hours
Perfluoropropane,
maximal expansion
occurs between 72 to 96
hours
X
Practical Tips 1
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How to achieve a single
bubble in the vitreous
cavity?
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X
Perpendicular needle entry
Penetrate the anterior
vitreous into mid vitreous
Draw back till needle tip
just in vitreous cavity
Position eye ball – needle
at uppermost site
Fast but not brisk
Turn eyeball till needle not
at uppermost position
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Practical Tips 2
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The gas is injected as a single
bubble by rotating the eye so
that the injection site is at the
most superior portion of the
eye, opposite the tear.
The bubble is rolled under the
flap of the tear, keeping the
face prone.
The bubble is positioned
against flap by rolling the
patient.
Horse shoes Tear
with RRD
Pneumatic retinopexy
(Cryotherapy + 0.3ml
100% C3F8 intraocular
injection)
2. Scleral buckling surgery
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Peritomy
Rectus muscle tagged
Mark break
Cryo
Preplace suture / scleral
tunnel
Buckle / encircling
Drainage
Closure
Main Aim
External steps
Internal steps
1. Seal retinal break
/Traction relieve
Buckle
Intraocular gas
2. Flatten retina
External drainage
Heavy liquid /
Gas fluid exchange
3. Formation of
Retino-choroidal
adhesion
Cryotherapy
Endolaser
Normal steps
Various solid silicone rubber scleral buckling element
(MIRA, inc)
Drainage
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Indication
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Difficulty in localizing
break
Immobile retina
Longstanding RD
Inferior RD
IOP rise hazardous
Technique
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Most bullous RD area
Avoid horizontal
meridian/vortex vein
Avoid areas close to
breaks
Special technique
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“DACE” for very bullous RD
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Drainage
Air injection
Cryo
Explant
How to locate a break??
Lincoff rules
How to locate a break??
Lincoff rules
How can a buckle work?
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Decrease the distance between
tear and RPE
Change of intraocular fluid
current
Relief of vitreous traction
(change of vector of force)
How can encircling work?
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Support vitreous base
Compartment effect
Enhance the buckle effect
Where to place the encircling band?
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The greatest diameter of the
eye ball – equator
Remember arc length vs cord
length
What determine the height of
buckle?
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The shape of the buckle
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Composition of the buckle (silicone
sponge vs. hard silicone)
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Suture placement with respect to
the dimensions of the buckle
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Suture tension
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Distribution of tension from the
suture to the buckle
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Intraocular pressure.
How does cryotherapy work?
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Joule-Thomson effect
Formation of intracellular
ice crystal and
mechanical disruption of
cell membrane during
freezing
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Till choroid turn bright
orange / retina turn white
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Effect in 10-12 days
Macula on RRD
pre op
Scleral Buckling +
Encircling +
Cryotherapy
post op VA = 20/20
3. Pars plana vitrectomy (PPV)
Main Aim
External steps
Internal steps
1. Seal retinal
break /Traction
relieve
Buckle
Intraocular gas
Silicone oil
2. Flatten retina
External
drainage
Heavy liquid /
Gas fluid
exchange
3. Formation of
Retino-choroidal
adhesion
Cryotherapy
Endolaser
Silicone oil property
TRD (Proliferative DMR)
Pre op VA = 20/200
TRD Post Op
VA = 20/50
Giant retinal tear with rolled
edge
PPV + PFC + laser + PFC
/ air Exchange + Silicone
oil