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Rhegmatogenous
Retinal
Detachment
Nawat Watanachai
2012
Little QUIZ (10min)






1. how to differentiate RRD/TRD/ERD
from fundus findings?
2. risk of PVR
3. contraindicatio...
Retinal Detachment: Definition


separation of the inner layers of the
retina from the underlying retinal
pigment epithel...
RD: Pathophysiology
3 basic mechanisms:
1. Rhegmatogenous retinal detachment (RRD)
2. Exudative retinal detachment (ERD)
3...
The Vitreous



Water 98-99% water
1-2%
 collagen type II fibres*
 salts, sugars
 glycosaminoglycan, hyaluronic acid
...
The Vitreous *


Condense and attach more at
Optic disc rim
Along blood vessels
Macula
Peripheral retinal abnormaliti...
Vitreous degeneration/ syneresis
Posterior Vitreous Detachment
Posterior Vitreous detachment

Weiss ring
Posterior vitreous detachment


Prevalence increase with
AXL
age
○ < 10% at < 50 yrs
○ 30% at 50-70 yrs
○ >60% at > 70 ...
Posterior vitreous detachment


Symptoms
most asymptomatic
photopsia
○ physical stimulate of vitreoretinal traction

f...
Vitreo-retinal adhesion

-Chronic traction  hyperpigmented area
-Acute traction  retinal break/ tear
Retinal Break/ tear
Rhegmatogenous retinal
detachment
-

A hole, tear, or break
in the neuronal layer
allowing fluid from the
vitreous cavity ...
RB and PVD*


acute symptomatic PVD
15% retinal tear



PVD with VH
50-70 % retinal tear



PVD without VH
10-12 % r...
Risks of RRD 1 *



Posterior vitreous detachment
Peripheral retinal lesions
enclosed oral bays
meridional folds
cyst...
Risks of RRD 2 *


Intraocular inflammation/infection
-Acute retinal necrosis syndrome
-Cytomegalovirus retinitis
-Ocular...
Risks of RRD 3 *








Choiroid/ retinal coloboma
Lens coloboma
Stickler syndrome
Goldmann-Favre syndrome
Marfan ...
Mortality/Morbidity*



1: 10,000 population : yr
15% of people with RD in one eye
 develop RD in the other eye. (life...
History





Floaters
Flashing light (photopsia)
Shadow in the peripheral visual field
Decreased visual acuity and a w...
History







Detachments anterior to the equator are
very unlikely to affect the VF
Detachment posterior to the equa...
History




FHx of RRD
History of trauma
previous surgery
cataract extraction/ esp c cpx (-L-’)
intraocular foreign b...
Physical examination




VA/ VF
IOP : hypotony of >4-5 mm Hg less than
the fellow eye is common
Vitreous
tobacco dust ...
Physical examination


Indirect ophthalmoscopy
with scleral depression



A 3-mirror contact lens
examination with a sli...
Physical examination


marked elevation of the retina, which
appears gray with dark blood vessels that
may lie in folds.
Retinal detachment
Which one is this case?
1. Rhegmatogenous retinal detachment (RRD)
2. Exudative retinal detachment (ERD...
Is this RRD/ TRD or ERD *
symptoms

RRD

TRD

ERD

floaters

++

+/-

+/-

flashing

++

-

-

Progressio
n of VA
loss

ac...
Is this RRD/ TRD or ERD *
signs

RRD

TRD

ERD

Shaffer’s
sign

+

-

-

PVD

++

-

+/-

VH

+/-

+/-

-

RD contour

con...
Workup for diagnosis



Lab study – unhelpful
Imaging – not necessary in most cases
Poor visualization  B-scan
Weird ...
CLINICAL FEATURES


Early



Long standing
CLINICAL FEATURES:early


Early
retina lost transparency and assumes a

gray, translucent appearance
fine, irregular co...
Recent rhegmatogenous retinal detachment showing loss of the
normal retinal transparency and irregular corrugations
CLINICAL FEATURES : early



fine details of the choroidal vasculature
obscured by overlying detached retina
within days...
CLINICAL FEATURES : early


If retina reattached within a week
most of cellular changes reversible



RPE cells underly...
CLINICAL FEATURES :early


Lincoff and Geiser reported 4 guidelines
for locating RB causing RRD *
determined by

○ locat...
ป๋า harvey lincoff
ณ NEI
Lincoff rule


total or superior RD
that cross midline
primary hole usually

within 1 clock hr. of
o'clock meridian



...
Lincoff rule


superotemporal RD
RB lies near superior edge of detached retina



superior nasal or temporal RD
RB lie...
Lincoff rule


inferior RD
higher side indicates

which side of the disc
an inferior hole lies
95% of the time



infer...
CLINICAL FEATURES:long standing


LONG-STANDING
progressive atrophy of all retinal layers
smooth contour and semitransp...
CLINICAL FEATURES :LONG-STANDING


RRD ≥ 3 mo.
RPE metaplasia at border of detachment



Most RRD surrounded by demarca...
CLINICAL FEATURES :LONGSTANDING


RRD > 6 mo.
Subretinal fibrosis
CLINICAL FEATURES :LONGSTANDING


RRD > 1 year
intraretinal cyst
can resolve if retinal reattach
CLINICAL FEATURES :LONGSTANDING


very long-standing
extensive capillary nonperfusion lead to

peripheral retinal NV
IO...
PROLIFERATIVE
VITREORETINOPATHY





occurs ~ 10% of all RRD which ¼ require
additional surgical intervention
most comm...
Classification
RD with vitreoretinopathy1983*
Grade

Name

Signs

A

Minimal

vitreous haze ,pigment clump

B

Moderate

w...
Classification of PVR 1991*
grade

features

A

vitreous haze ,pigment clump,pigment cluster inferior
retina

B

wrinkling...
Management RRD


Retinal repositioning
Push the retina-eyewall
○ Pneumatic retinopexy
○ Scleral buckle procedure
○ vitre...
Retinal Repositioning
○ Pneumatic retinopexy
○ Scleral buckle procedure
Scleral balloon

○ vitrectomy
Pneumatic retinopexy *


intravitreal gas tamponade RB temporary
100%C3F8




4X at 72 hrs

SRF will resolve
Need lase...
Pneumatic retinopexy*


Contraindications
Break > 1 clock hr
Break inferior 4 clock hr
PVR grade C,D
Cloudy ocular me...
Pneumatic retinopexy


Relative contraindications
Extensive lattice degeneration
Aphakia or pseudophakia
Results PR



50-80% reattach with single PR
60-98% reattach with reoperation
Scleral buckle



Indent sclera with solid silicone
Segmental versus Encircling Buckles
Scleral buckle : Segmental *


usually reserved for
RRD < 1 clock hour
posterior breaks



primary advantage
easy of ...
Scleral buckle : Segmental





not provide retinal support elsewhere
vitreoretinal traction away from
segmental elemen...
Scleral buckle :encircling


particularly indicated in *
multiple breaks in different quadrants
Aphakia/ pseudophakia
...
Scleral buckle


Intraoperative complications
Corneal clouding
○ epithelial edema from IOP rising
Miosis
○ hypotony , i...
Scleral buckle


Post-op complications
Glaucoma
Anterior segment ischemia
Infection/extrusion
CD
○ vortex vein obstru...
Scleral buckle


Post-op complications
Macular pucker
Motility disturbance
Change refractive error
○ greater in phakic...
Scleral buckle



macula off VA ≥ 20/50 ~ 40-60%
duration of macula detachment relate
with final VA
VA ≥ 20/40
71% if d...
Temporary balloon





Lincoff’s balloon
external device indent
sclera to allow
cryotherapy or laser
induce choriorerti...
Vitrectomy


Remove vitreous
Remove vitreoretinal traction on RB




FAX
Injection of gas or liquid silicone





A...
Vitrectomy


Advantages
better intraoperative control in difficult

situation
improve visualization of peripheral break...
Vitrectomy


Advantages
high intraoperative reattach rate
remove of vitreous opacity
remove capsular opacity
internal...
Vitrectomy


Advantages
less post-op change refractive error
lower incidence of post-op double vision
lower incidence ...
Vitrectomy


Disadvantages
delay visual restitution from gas tamponade
position after operation
air travel avoid
Vitrectomy


Disadvantages
higher rate of cataract in phakic eye
higher rate of iatrogenic break
higher rate of post-o...
Vitrectomy




Results
Anatomical reattach 64-100%
Functional results
VA ≥ 20/50 63%
Compare with SB VA ≥ 20/50

39-5...
Seal the break(s)




Diathermy (obsolete)
Laser
cryo
Laser photocoagulation




usually cannot seal RB if presence SRF
may be use to create barrier to prevent
progression o...
Laser photocoagulation






slit-lamp
biomicroscope with
contact lens
laser indirect
ophthalmoscope
(LIO)
endolaser
Laser photocoagulation*



Slit-lamp
 better magnified
 Safer in inexpertise

operator
 Less need of corneal
care dur...
A.posteriorly located retinal tear
B.treat by laser photocoagulation
Laser photocoagulation *


Compared with diathermy and cryopexy
less breakdown of blood–ocular barrier
thermal effect c...
Cryoretinopexy





RD with very shallow fluid can be cure by
cryoretinopexy alone
using cryoprobe and indirect ophthal...
Cryoretinopexy





freezing or whitening of RPE will noticed first,
followed by delineation of edges of retinal tear
an...
Cryoretinopexy


histologic response depends on whether
RPE alone or RPE and overlying detached
retina together are froze...
Cryoretinopexy


If both RPE and overlying retina frozen
cellular connections between retina and RPE

consisting of desm...
Cryoretinopexy


Disadvantage
dispersion of pigment epithelial cells, which can

result in subretinal pigmentary changes...
Cryoretinopexy


Some study suggest cryopexy is risk factor of
post-op PVR whereas others not show an
association
minimi...
Cryoretinopexy : disadvantage


induce choroidal congestion &hyperemia
although not permanent
may complicate drainage of...
Nw2013 RetinalDetachment
Nw2013 RetinalDetachment
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Nw2013 RetinalDetachment

  1. 1. Rhegmatogenous Retinal Detachment Nawat Watanachai 2012
  2. 2. Little QUIZ (10min)      1. how to differentiate RRD/TRD/ERD from fundus findings? 2. risk of PVR 3. contraindication for pneumatic retinopexy 4. compare PPV vs SBP for RRD 5. compare laser vs cryo retinopexy
  3. 3. Retinal Detachment: Definition  separation of the inner layers of the retina from the underlying retinal pigment epithelium (RPE, choroid)
  4. 4. RD: Pathophysiology 3 basic mechanisms: 1. Rhegmatogenous retinal detachment (RRD) 2. Exudative retinal detachment (ERD) 3. Traction retinal detachments (TRD)
  5. 5. The Vitreous   Water 98-99% water 1-2%  collagen type II fibres*  salts, sugars  glycosaminoglycan, hyaluronic acid  very few cells  mostly phagocytes  hyalocytes of Balazs (surface/ hyaluronate)  refractive index of 1.336
  6. 6. The Vitreous *  Condense and attach more at Optic disc rim Along blood vessels Macula Peripheral retinal abnormalities ○ Chorioretinal scar ○ Lattice degeneration and others Ora serrata (Vitreous base: 2mmA, 4mmP)
  7. 7. Vitreous degeneration/ syneresis
  8. 8. Posterior Vitreous Detachment
  9. 9. Posterior Vitreous detachment Weiss ring
  10. 10. Posterior vitreous detachment  Prevalence increase with AXL age ○ < 10% at < 50 yrs ○ 30% at 50-70 yrs ○ >60% at > 70 yrs  Other associate Cataract Sx, within 2 yrs after surgery ○ ICCE 84% = ECCE c PC tear76% ○ ECCE c intact PC40% ○ PE 30%  inflammation / uveitis  trauma  syndromes
  11. 11. Posterior vitreous detachment  Symptoms most asymptomatic photopsia ○ physical stimulate of vitreoretinal traction floaters ○ Weiss ring and V.condensation in the posterior hyaloid surface ○ vitreous opacity eg. blood , glia cell VH rupture of retinal vessel
  12. 12. Vitreo-retinal adhesion -Chronic traction  hyperpigmented area -Acute traction  retinal break/ tear
  13. 13. Retinal Break/ tear
  14. 14. Rhegmatogenous retinal detachment - A hole, tear, or break in the neuronal layer allowing fluid from the vitreous cavity to seep in between and separate sensory and RPE layers
  15. 15. RB and PVD*  acute symptomatic PVD 15% retinal tear  PVD with VH 50-70 % retinal tear  PVD without VH 10-12 % retinal tear
  16. 16. Risks of RRD 1 *   Posterior vitreous detachment Peripheral retinal lesions enclosed oral bays meridional folds cystic retinal tuft lattice degeneration     Myopia Senile retinoschisis Cataract extraction Trauma
  17. 17. Risks of RRD 2 *  Intraocular inflammation/infection -Acute retinal necrosis syndrome -Cytomegalovirus retinitis -Ocular toxocariasis -Ocular toxoplasmosis -Pars planitis
  18. 18. Risks of RRD 3 *        Choiroid/ retinal coloboma Lens coloboma Stickler syndrome Goldmann-Favre syndrome Marfan syndrome Homocystinuria Ehlers-Danlos syndrome
  19. 19. Mortality/Morbidity*   1: 10,000 population : yr 15% of people with RD in one eye  develop RD in the other eye. (lifetime)  Risk of bilateral RD is increased (25-30%) in patients who have had bilat eral cataract extraction.
  20. 20. History     Floaters Flashing light (photopsia) Shadow in the peripheral visual field Decreased visual acuity and a wavy distortion of objects (metamorphopsia)
  21. 21. History     Detachments anterior to the equator are very unlikely to affect the VF Detachment posterior to the equator can be isolated with visual field testing, but many patients aware of a defect only when it involved the posterior pole and macula. Photopsia and floaters  not helpful in locating the position of the retinal tear or detachment visual field defect  very specific for locating the detachment.
  22. 22. History    FHx of RRD History of trauma previous surgery cataract extraction/ esp c cpx (-L-’) intraocular foreign body removal retinal procedures
  23. 23. Physical examination    VA/ VF IOP : hypotony of >4-5 mm Hg less than the fellow eye is common Vitreous tobacco dust (Shafer’s sign), pathognomonic for a retinal tear in 70% of cases with no previous eye disease or surgery.
  24. 24. Physical examination  Indirect ophthalmoscopy with scleral depression  A 3-mirror contact lens examination with a slitlamp
  25. 25. Physical examination  marked elevation of the retina, which appears gray with dark blood vessels that may lie in folds.
  26. 26. Retinal detachment Which one is this case? 1. Rhegmatogenous retinal detachment (RRD) 2. Exudative retinal detachment (ERD) 3. Traction retinal detachments (TRD)
  27. 27. Is this RRD/ TRD or ERD * symptoms RRD TRD ERD floaters ++ +/- +/- flashing ++ - - Progressio n of VA loss acute chronic Subacute/ chronic Fluctuation of vision - +/- +
  28. 28. Is this RRD/ TRD or ERD * signs RRD TRD ERD Shaffer’s sign + - - PVD ++ - +/- VH +/- +/- - RD contour convex concave bullous RD surface corrugate Ridge/ wavy smooth shifting +/- - ++ associated Myopia/ trauma/ Sx DM CTD
  29. 29. Workup for diagnosis   Lab study – unhelpful Imaging – not necessary in most cases Poor visualization  B-scan Weird cases ○ IOFB/parasite
  30. 30. CLINICAL FEATURES  Early  Long standing
  31. 31. CLINICAL FEATURES:early  Early retina lost transparency and assumes a gray, translucent appearance fine, irregular corrugations usually present ○ result of intraretinal edema
  32. 32. Recent rhegmatogenous retinal detachment showing loss of the normal retinal transparency and irregular corrugations
  33. 33. CLINICAL FEATURES : early   fine details of the choroidal vasculature obscured by overlying detached retina within days of RRD outer retinal degeneration starts to occur photoreceptor damage related to height and duration circulation of inner retina not affected
  34. 34. CLINICAL FEATURES : early  If retina reattached within a week most of cellular changes reversible  RPE cells underlying RRD released into SRF and may pass through RB into vitreous cavity tobacco dust 70% of case
  35. 35. CLINICAL FEATURES :early  Lincoff and Geiser reported 4 guidelines for locating RB causing RRD * determined by ○ location of causative break ○ anatomic barriers (optic n.,ora serrata, existing chorioretinal adhesions) ○ effect gravity on SRF in upright position  Note : only for fresh RD with 1 RB
  36. 36. ป๋า harvey lincoff ณ NEI
  37. 37. Lincoff rule  total or superior RD that cross midline primary hole usually within 1 clock hr. of o'clock meridian  12- If detachment extends more inferiorly on either nasal or temporal side RB usually on same side of 12-o'clock meridian
  38. 38. Lincoff rule  superotemporal RD RB lies near superior edge of detached retina  superior nasal or temporal RD RB lies within 1.5 clock hr. of the highest border 98%
  39. 39. Lincoff rule  inferior RD higher side indicates which side of the disc an inferior hole lies 95% of the time  inferior detachment is bullous primary hole lies above horizontal meridian
  40. 40. CLINICAL FEATURES:long standing  LONG-STANDING progressive atrophy of all retinal layers smooth contour and semitransparent some cases, cystic spaces atrophy and depigmentation of underlying RPE
  41. 41. CLINICAL FEATURES :LONG-STANDING  RRD ≥ 3 mo. RPE metaplasia at border of detachment  Most RRD surrounded by demarcation line eventually progress; nonetheless, surgical repair of these eyes has an excellent prognosis
  42. 42. CLINICAL FEATURES :LONGSTANDING  RRD > 6 mo. Subretinal fibrosis
  43. 43. CLINICAL FEATURES :LONGSTANDING  RRD > 1 year intraretinal cyst can resolve if retinal reattach
  44. 44. CLINICAL FEATURES :LONGSTANDING  very long-standing extensive capillary nonperfusion lead to peripheral retinal NV IOP can rise ○ TM impeded by pigment clumps or the outer segments of photoreceptors
  45. 45. PROLIFERATIVE VITREORETINOPATHY    occurs ~ 10% of all RRD which ¼ require additional surgical intervention most common cause of failure to repair risk factor aphakia , preop PVR , extensive RD , uveitis , excessive cryo, GRT, massive VH
  46. 46. Classification RD with vitreoretinopathy1983* Grade Name Signs A Minimal vitreous haze ,pigment clump B Moderate wrinkling inner retinal surface,roll edge RB , retinal stiffness , vessel tortous C Marked full thickness fix retinal fold C1,C2,C3 D Massive full thickness fix retinal fold 4 quadrants D1 wide ,D2 narrow D3 close not seen optic disc
  47. 47. Classification of PVR 1991* grade features A vitreous haze ,pigment clump,pigment cluster inferior retina B wrinkling inner retinal surface,roll and irregular edge RB , retinal stiffness , vessel tortous ,vitreous mobility , CP1-12 posterior to equator : focal , diffuse ,or circumferential full thickness fold , subretinal strands CA1-12 anterior to equator : focal ,diffuse ,or circumferential full thickness fold , subretinal strands
  48. 48. Management RRD  Retinal repositioning Push the retina-eyewall ○ Pneumatic retinopexy ○ Scleral buckle procedure ○ vitrectomy Remove SRF/ perfluorocarbon liquid Remove fibrous membrane/traction  Seal the break(s) Cryoretinopexy Laser retinopexy  Temponade the retina Gas/ silicone oil
  49. 49. Retinal Repositioning ○ Pneumatic retinopexy ○ Scleral buckle procedure Scleral balloon ○ vitrectomy
  50. 50. Pneumatic retinopexy *  intravitreal gas tamponade RB temporary 100%C3F8   4X at 72 hrs SRF will resolve Need laser / cryo to permanently close the RB
  51. 51. Pneumatic retinopexy*  Contraindications Break > 1 clock hr Break inferior 4 clock hr PVR grade C,D Cloudy ocular media Uncontrolled or severe glaucoma Can’t maintain position
  52. 52. Pneumatic retinopexy  Relative contraindications Extensive lattice degeneration Aphakia or pseudophakia
  53. 53. Results PR   50-80% reattach with single PR 60-98% reattach with reoperation
  54. 54. Scleral buckle   Indent sclera with solid silicone Segmental versus Encircling Buckles
  55. 55. Scleral buckle : Segmental *  usually reserved for RRD < 1 clock hour posterior breaks  primary advantage easy of placement minimal refractive error change avoid effects of large encircling elements  however, for most large posterior breaks , all MH prefer closure with gas and vitrectomy
  56. 56. Scleral buckle : Segmental    not provide retinal support elsewhere vitreoretinal traction away from segmental element not supported, which may result in formation of new RB because of limited support , some surgeon prefer encircling when possible
  57. 57. Scleral buckle :encircling  particularly indicated in * multiple breaks in different quadrants Aphakia/ pseudophakia High/pathologic myopia diffuse vitreoretinal pathologic eg. extensive lattice degeneration or vitreoretinal degenerations PVR ≥ grade B
  58. 58. Scleral buckle  Intraoperative complications Corneal clouding ○ epithelial edema from IOP rising Miosis ○ hypotony , inflammation Scleral perforate Drainage complications ○ retinal incarcerate/perforate ○ choroidal hemorrhage
  59. 59. Scleral buckle  Post-op complications Glaucoma Anterior segment ischemia Infection/extrusion CD ○ vortex vein obstrution ○ drainage procedure CME
  60. 60. Scleral buckle  Post-op complications Macular pucker Motility disturbance Change refractive error ○ greater in phakic eye ○ Myopic or hyperopic? ERD ○ cause unknown
  61. 61. Scleral buckle   macula off VA ≥ 20/50 ~ 40-60% duration of macula detachment relate with final VA VA ≥ 20/40 71% if detach < 10 days VA ≥ 20/40 27% if detach 11days-6 weeks VA ≥ 20/40 14% if detach > 6 weeks
  62. 62. Temporary balloon    Lincoff’s balloon external device indent sclera to allow cryotherapy or laser induce choriorertinal adhesion especial useful in inferior RD when PR not possible
  63. 63. Vitrectomy  Remove vitreous Remove vitreoretinal traction on RB   FAX Injection of gas or liquid silicone    Avoid complication from SB Complete tamponade of vitreous cavity
  64. 64. Vitrectomy  Advantages better intraoperative control in difficult situation improve visualization of peripheral break Internal drainage avoid complication of external drainage
  65. 65. Vitrectomy  Advantages high intraoperative reattach rate remove of vitreous opacity remove capsular opacity internal photocoagulation / cryotherapy RB drainage suprachoroidal fluid if present
  66. 66. Vitrectomy  Advantages less post-op change refractive error lower incidence of post-op double vision lower incidence of ERD avoid hazard of scleral perferation
  67. 67. Vitrectomy  Disadvantages delay visual restitution from gas tamponade position after operation air travel avoid
  68. 68. Vitrectomy  Disadvantages higher rate of cataract in phakic eye higher rate of iatrogenic break higher rate of post-op IOP rising higher rate of post-op new/miss break special equipment higher cost
  69. 69. Vitrectomy    Results Anatomical reattach 64-100% Functional results VA ≥ 20/50 63% Compare with SB VA ≥ 20/50 39-56%
  70. 70. Seal the break(s)    Diathermy (obsolete) Laser cryo
  71. 71. Laser photocoagulation    usually cannot seal RB if presence SRF may be use to create barrier to prevent progression of RD esp. useful in chronic inferior RD systemic illness contraindicate to surgery
  72. 72. Laser photocoagulation    slit-lamp biomicroscope with contact lens laser indirect ophthalmoscope (LIO) endolaser
  73. 73. Laser photocoagulation*   Slit-lamp  better magnified  Safer in inexpertise operator  Less need of corneal care during laser  Less pain LIO  significant cataracts, PCO, mild VH more easily treated with LIO  indentation  Need more skill  not be readily available  Any patient position
  74. 74. A.posteriorly located retinal tear B.treat by laser photocoagulation
  75. 75. Laser photocoagulation *  Compared with diathermy and cryopexy less breakdown of blood–ocular barrier thermal effect confined predominantly to retina and pigment epithelium little or no effect on choroid or sclera induces adhesive effect between retina & pigment epithelium within 24hr
  76. 76. Cryoretinopexy    RD with very shallow fluid can be cure by cryoretinopexy alone using cryoprobe and indirect ophthalmoscope testing cryoprobe prior to make sure probe is freezing
  77. 77. Cryoretinopexy   freezing or whitening of RPE will noticed first, followed by delineation of edges of retinal tear and whitening of retina excessive freezing or ice crystal formation should be avoided
  78. 78. Cryoretinopexy  histologic response depends on whether RPE alone or RPE and overlying detached retina together are frozen only RPE froze once retina reattached ○ pigment epithelial hyperplasia ○ loss of retinal outer segments ○ normal microvillous interdigitations seen between retina and RPE are missing
  79. 79. Cryoretinopexy  If both RPE and overlying retina frozen cellular connections between retina and RPE consisting of desmosome formation between retinal glia and pigment epithelium or direct contact between retinal glia and Bruch's membrane
  80. 80. Cryoretinopexy  Disadvantage dispersion of pigment epithelial cells, which can result in subretinal pigmentary changes after reattachment dispersion of viable pigment epithelial cells capable of causing PVR following cryopexy
  81. 81. Cryoretinopexy  Some study suggest cryopexy is risk factor of post-op PVR whereas others not show an association minimize cryotherapy-induced pigment epithelial cell dispersion by ○ not over treating ○ avoiding unnecessary scleral depression of treated areas  localization and examination with scleral depression should be performed before cryopexy
  82. 82. Cryoretinopexy : disadvantage  induce choroidal congestion &hyperemia although not permanent may complicate drainage of SRF through treated areas  breakdown of BRB cause post-op CME and ERD

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