diabetic retinopathy vitrectomy

1. Surgery for Proliferative Diabetic
Retinopathy
Dr Mamta Manik

2. Introduction
• Diabetic retinopathy is now one of leading causes
of potentially irreversible blindness in working age
population.
• Large number of eyes, however, progress toward
complications requiring surgical management
despite aggressive and valuable interventions.
• PPV was first introduced by Machemer et al. in
1970
• There have been vast improvement both in surgical
technique and outcomes

3. ETDRS Classification of Diabetic
Retinopathy

4. Epidemiology
• Cumulative incidence of PDR after 20 yr duration
is about 14%.
• Wisconsin epidemiologic studies, the prevalence
of proliferative retinopathy was 60% after 25
years of diabetes in younger diabetic patients,
but in older diabetics it varied from 20 to 30%.
• Prevalence of blindness (VA <3/60 better eye)
approximately 5% (range 3-7%) and may be as
high as 8%

5. Pathophysiology
• Initial insult is retinal ischaemia leading to the production
of angiogenic factors
• Interaction between several angiogenic factors with
vascular endothelial growth factor (VEGF) being
prominent.
• New vessels proliferate in the vitreoretinal interface, with
varying degrees of fibrous tissue proliferation
• Development of posterior vitreous detachment and/or
contraction of these fibrovascular membrane
• Vitreous haemorrhage, tractional retinal detachment,
and combined tractional–rhegmatogenous retinal
detachment

7. Pan Retinal Photocoagulation
mainstay of tt of PDR
Avoids the need of vitrectomy

9. Indications of Vitrectomy
• Media opacity
– Severe Nonclearing Haemorrhage
• Vitreous
• Subhyaloid
• Premacular
– Anterior Segment Neovascularization with Vitreous Haemorrhage
• Tractional defects
– TRD involving or threatening Fovea
– Combined tractional and rhegmatogenous detachment
– Progressive fibrovascular proliferation despite adequate laser
– Epiretinal membrane or opacified vitreous face causing visual loss
• Complication of previous vitrectomy surgery
• Ghost cell/ Hemolytic glaucoma
• Anterior hyaloid fibrovascular proliferation despite adequate laser

10. Vitreous haemorrhage
• Grading scale
– Grade 0 No vitreous haemorrhage entire retina seen
– Grade I
• Some hemorrhage present, which obscures between a total of 1 to 5 clock hours of
retina.
• Laser photocoagulation (PRP) can be successfully performed
– Grade II
• Hemorrhage obscures between a total of 5 to 10 clock hours of central and/or
peripheral retina, or
• large hemorrhage is located posterior to the equator, with varying clock hours of
anterior retina visible.
• Laser is feasible, but a full panretinal photocoagulation (PRP) can not be placed
– Grade III
• red reflex is present,
• no retinal detail seen posterior to the equator,
• precluding any photocoagulation
– Grade IV Dense VH with no red reflex present

11. Vitreous Haemorrhage
• Early vitrectomy, within 1–4 months from onset,
results in earlier recovery of vision and better
functional outcome after 2 and 4 years
• Benefit is greater in patients with type 1
diabetes mellitus, compared to type 2.
– Macular edema is more common in type II
– PVD more common in type II
• Dense premacular (subhyaloidal) hemorrhage

13. Timing of vitrectomy
• Duration of hemorrhage,
• Type of diabetes (I or II)
• Severity of retinopathy
• Status of the fellow eye ( Blind or rapidly
progressive visual loss)
• Premacular or intragel Hg
• Prior laser treatment (early if no laser done)

14. Favorable factors
• Preoperative visual acuity of 5/200 or better.
• Absence of NVI OR NVG.
• Minimal cataract.
• PRP of at least one fourth of the fundus

15. Tractional Retinal Detachment

16. Indications
• Tractional macular Detachment
• Peripheral tractional detachment threatening macula
• Vitreopapillary traction
• Traction involving Papillomacular bundle
Visual improvement has been reported in 59 to 80% of
cases, but vision equal to or greater than 20/200 is
achieved in only 21 to 58%

17. MACULAR TRACTION RETINAL
DETACHMENT
• Charles and Flinn studied the natural history
of diabetic extramacular traction retinal
detachment.
• They found a progression to macular
detachment in only 13.8% of eyes at 1-year
follow-up.

18. Favorable factors
• Age <50 years,
• Preoperative panretinal photocoagulation
• Visual acuity >5/200;
• No or few iris neovascularizations or retinal
proliferations;
• Macular detachments <30 days, and
• No iatrogenic breaks.6,25

19. COMBINED TRACTION-RHEGMATOGENOUS
RETINAL DETACHMENT
• Extramacular rhegmatogenous detachments
frequently progress to involve the macula,
leading to rapid and severe visual loss.
• Thus, surgical repair is indicated in combined
detachments, whether or not the macula is
involved.

20. Severe fibrovascular proliferation
• Major threat to profound loss of vision
• Early vitrectomy
– Severe fibrovascular proliferation & moderately
severe Neovascularization despite extensive PRP
– Severe fibrovascular Proliferation
• Stable or improved vision in 78% cases

21. Macular Edema and Traction
• May occur after extensive PRP or premacular
haemorrhage
• Vitreopapillary traction
• Diabetic epiretinal membranes

22. Neovascular Glaucoma
• Extensive PRP or cryotherapy.
• Intravitreal anti- VEGF, may be helpful as short-
term adjunct to PRP or when PRP fails to cause
regression of rubeosis
• Opaque optical media, as vitreous hemorrhage or
cataract, controlled PRP can only be performed
after vitrectomy and/or cataract extraction
• Silicone oil tamponade prevents recurrent
vitreous hemorrhage and may induce regression
of rubeosis

23. Preoperative evaluation
• Optimal blood glucose management may be
protective against perioperative infection.
• Patients should be well informed about
adjustments of medications, especially those for
blood glucose and blood pressure control.
• Anticoagulants as well as antiplatelet medications
must be stopped or substituted at the surgeon’s
suggestion.
• Patients on dialysis, surgery has to be arranged
between dialysis sessions.

24. Preoperative Evaluation
• Correlate the history of visual decrease with
possible anatomic changes
• B Scan
– Opacified media preventing fundus visualization,
as cataract, intracameral or intravitreal
hemorrhage
– Most relevant information, as the presence or
absence of vitreoretinal adhesions, vitreoschisis,
retinal detachment, or other subretinal opacities

25. Pre-Operative Anti-Vegf
• Preoperative antiangiogenic drug decrease the
risk of recurrent intravitreal hemorrhage or
neovascular glaucoma with rubeosis iridis.
• Preoperative injections 7 days prior to surgery
– Improve the outcome and
– Facilitate surgical manipulations in diabetic
tractional detachment.

26. Pre-Operative Anti VEGF
• Potential adverse effect because fibrovascular
membrane contraction can lead to rapid
development or progression of tractional
retinal detachment.
• Timing of vitrectomy surgery may therefore be
critical to avoid this complication..

27. Cataract
• Cataract extraction alone or with primary lens
implantation, followed by vitrectomy
• Combined operation in single procedure
• Advantage is much better intraoperative access
to the vitreous base
• Procedure of choice is phacoemulsification
• All three sclerotomies are performed and trocars
inserted before cataract surgery to avoid
pressure changes

29. Instruments
1. 3-4 Port trocar
2. 120D lens , for peeling: 60D front lens
3. Vitreous cutter
4. Fluid needle
5. Eckardt forceps
6. horizontal scissors or vertical scissors
7. Membrane pic or knob spatula
8. Endodiathermy
9. Laser therapy
10. Scleral depressor
Dye
Triamcinolone or Trypan blue or BBG
Tamponade
air, 12–14% C3F8 or silicone oil

30. Surgical Steps
Vitreous Haemorrhage
1. 3-Port system
2. Core vitrectomy
3. Posterior vitreous
detachment and
peripheral vitrectomy
4. Endodiathermy
5. Panretinal
photocoagulation
6. Tamponade
7. Removal of the trocar
cannulas
Tractional Detachment
1. 4-Port system
2. Core vitrectomy
3. Peripheral vitreous rhexis
4. Bimanual dissection of
tractional membranes
5. Apply PRP
6. Tamponade
7. Removal of the trocars

31. In combined procedure
• Infusion is turned on only when the cutter is in
the eye and vitreous removal can be started
simultaneously.
• Otherwise, the infusion pressure will move
the lens implant anteriorly and iris
incarceration into the wound can occur

32. Posterior hyaloid status
• Eyes with complete PVD
• Eyes with incomplete posterior hyaloid
separation
• Eyes with subtotal vitreous adhesion

33. Triamcinolone Acetonide
• Facilitate identification of the vitreous cortex,
• Due to its anti-inflammatory potential it may
also help to prevent fibrin exudation in
proliferative diabetic retinopathy.
• Intravitreal doses of 2–4 mg of triamcinolone
acetonide will offer sufficient staining with no
retinal toxicity.

34. PVD Present
• Opening made in posterior hyaloid
• Blood might be pooled at the posterior pole, usually
unclotted, and can be aspirated now with a soft-
tipped fluid needle or Cutter

36. PVD & Peripheral vitrectomy
• If tractional membranes are present at the
posterior pole, do not induce PVD because it
may cause breaks in the central retina
• Try to remove all peripheral vitreous with
remaining blood in it (this may wash out
postoperatively and be an additional source of
postoperative vitreous haemorrhage)

37. Incomplete post hyaloid Separation
• Tractional membranes are present on the
posterior pole.
• PVD should not be induced with the usual
method of suction over the posterior pole and
pulling on the vitreous face
• In most cases of PDR, a partial vitreous
detachment is present (i.e vitreous is still
attached at the disc but partially detached in the
mid-periphery) or
• Create peripheral Vitreous detachment

38. • Create an opening of the posterior hyaloid and
remove the vitreous along the posterior vitreous
face on a constant level in a circular fashion
(peripheral vitreous rhexis).
• Do not vitrectomize the area where the vitreous
is attached.
• Carefully vitrectomize further from the periphery
toward the beginning of the tractional
membranes
• Address the membranes

39. Membrane Dissection
Commonly used:
(1) segmentation,
(2) delamination,
(3) “en bloc” dissection,
(4) combined.

40. Membrane Dissection
• Segmentation
– Membrane is
segmented by cutting
bridging tissue between
foci of fibrovascular
adhesion
• Delamination
– Connections between
the posterior hyaloid and
fibrovascular tissue and
the internal limiting
membrane are cut

41. Segmentation

42. Delamination

43. Membrane Dissection
• “En bloc” technique
removal of the vitreous
and associated
vitreoretinal membranes
as a single unit
• Combination technique

44. Fibrovascular tissue that is firmly attached to the disc is reduced
with the vitreous cutter

45. Bimanual Membrane Surgery

46. Subtotal posterior vitreous adhesion
• Access to the subhyaloidal space is difficult.
• Gentle suction to find lesser adherent areas
vitreous (subhyaloidal hemorrhage)
• Vitrector, sharp blade or subretinal pick is used
to create an opening into the subhyaloidal
space.
• Safest areas for such manoeuvres are around
the optic disc
• Dissection is performed centripetally

47. Combined tractional and
rhegmatogenous detachment
• Dissection of tissue is started usually in an area
distant from the detached retina
• Preparation of tissue from the centre to the
periphery is advisable.
• Perfluorocarbon can be used to stabilize the
posterior retina.
• Peripheral retinectomies are needed in eyes
where reoperations become necessary and
severe anterior hyaloid fibrovascular proliferation
has developed

48. Endodiathermy
• Cauterize retinal bleeding sites with
endodiathermy.
• Start with relatively low energy, as too vigorous
endodiathermy may create breaks in ischemic
retinal tissue.
• Avoid diathermy on the disc; this may cause
destruction of nerve fibre bundles
• In Bimanual system aspirate the blood with one
hand and cauterize the bleeding source with
endodiathermy

49. Pan Retinal Photocoagulation
• Complete PRP intraoperatively
• Use the scleral depressor and apply a dense
PRP up to the ora serrata

50. Tamponades
• Prolonged tamponade in cases of retinal
breaks with traction, retinal detachments or
diffuse hemorrhage
• Gases as SF6, C2F6, or C3F8
• Silicone oil is of choice in reoperations or
severe cases, if a longer tamponade is
required,

51. Diabetic Vitrectomy Results

52. Complications
• Intraoperative
– Corneal edema
– Lens touch
– Pupillary constriction
– Intraocular haemorrhage
– Retinal break or
detachment
– Subretinal PFCl or Silicone
oil
• Postoperative
– NVI and NVG
– Cataract
– Fibrinoid Syndrome
– Postoperative Vitreous
cavity haemorrhafe
– Anterior Hyaloidal
fibrovascular proliferation

53. Post vitrectomy Vitreous Hg
• Recent study suggest decrease from 75% in
1980 to 30% today
• Early POVH in 1st 4 weeks postoperatively
• Late POVH > 4 weeks

54. Early vitreous cavity haemorrhage
• Common complication after diabetic vitrectomy (30–75%)
• Source
– Dissected fibrovascular tissue and
– Dispersion of erythrocytes from residual peripheral vitreous
gel.
• Preventive strategies
– Careful dissection of fibrovascular membranes with complete
haemostasis (by diathermy or direct pressure)
– Intraocular tamponade with C3F8
– Air and SF6 no role although variable findings have been
reported.1,2,3
– Intravitreal anti-VEGF therapy with bevacizumab administered
1 week .6,7,8
• Clear spontaneously within 2–6 weeks.
• If persists > 6wks resurgery

55. Delayed Vitreous cavity Haemorrhage
• If POVH persists > 6 weeks or occurs after 4 week PO following initial period
of clear vitreous cavity
• Causes
– Residual fibrovascular membranes,
– Reproliferative retinal neovascularisation,
– Sclerotomy entry site neovascularisation (fibrovascular ingrowth).8,9
• Preventive strategy
– Laser photocoagulation if existing panretinal photocoagulation is inadequate.10
– Cryotherapy to the peripheral retina and
– Cryotherapy to sclerotomy entry sites.9
• Fail to clear spontaneously
– Vitreous cavity washout,
– Dissection of residual or reproliferative fibrovascular membranes,
– Silicone oil tamponade.

56. Postoperative vitreous cavity
haemorrhage
• More in phakics as lens acts as a barrier
between vitreous cavity and treabecular
meshwork
• Spontaneous clearing of haemorrhage
(moderate to severe) in 3.8 weeks in apakics
compared to 11.6 wks in phakics

57. Fibrinoid syndrome
• Breakdown of the blood–retina barrier with in
intraocular fibrin deposition.
• Massive fibrin formation in the vitreous cavity
(the fibrinoid syndrome)
– Tractional retinal detachment,
– Pupillary block,
– Ciliary body detachment,
– Hypotony
– Rubeosis iridis with neovascular glaucoma

58. • Risk Factors
– Young Age
– Lensectomy,
– Extensive dissection,
– Intensive panretinal photocoagulation or
– Scleral buckle surgery
• Treatment
– topical corticosteroids
– tPA injection in AC
– PST
– Substantial fibrin deposition repeated vitrectomy,
fibrin removal and silicone oil injection.

59. Anterior Hyaloidal Fibrovascular
Proliferation
• Most severe complication
• 13% of cases
• Growth of neovascular tissue onto the
vitreous base, the anterior retina, ciliary body,
lens capsule and iris.
• Patients may present with rubeosis iridis,
vitreous hemorrhage, peripheral tractional
retinal detachment or hypotony

60. • Risk factors
– Male gender,
– Type I diabetes,
– Phakic patients,
– Insufficient panretinal photocoagulation,
– Severe ischemia with recurrent neovascularizations,
– Previous surgery with placement of a scleral buckle.
• Treatment cataract extraction, lensectomy, extensive
laser or cryopexy, and anterior dissection with eventual
retinectomy
• Endoscopic Vitrectomy
• Preoperative Anti vegf helpful

61. Recent Advances

63. Important Studies

64. DRVS Group I (VH)
• Severe vitreous hemorrhage (visual acuity
5/200 or less) ,
• 616 patients recruited
• Early vitrectomy (1 to 6 months after the
onset of hemorrhage)
• Conventional management
– vitrectomy was carried out 1 year later if
hemorrhage persisted;
– vitrectomy was carried out sooner if retinal
detachment -involving the center of the macula
occurred.

65. Results
• Final visual acuity of 20/40 or better in 25%
of cases (at 2-year follow-up), compared
with 15%
•
• Advantage for early vitrectomy remained
after 4 years of follow-up

66. DRVS group II (FVP)
• Severe fibrovascular proliferations with VA 10/200
or better
• 381 patients recruited
• Eligible eyes were assigned either to early
vitrectomy or to conventional management.
• Conventional management
– Photocoagulation when indicated,
– Vitrectomy if a severe vitreous hemorrhage occurred
and failed to clear spontaneously during a 6-month
waiting period or
– Retinal detachment involving the center of the macula

67. Result
• Rate of final vision equal to or greater than
20/40 was 44% for the early vitrectomy group
as compared to 28% in the conventional group
with 4 years follow up

68. Conclusion
• Most patients will regain or retain useful vision after
diabetic vitrectomy, although the visual outcome
remains unpredictable.
• Diabetic vitrectomy has been demonstrated to
significantly improve vision-related quality of life.
• Early vitrectomy for diabetic vitreous haemorrhage has
also been shown to be a highly cost-effective
intervention.
• Surgical outcome after diabetic vitrectomy has continued
to steadily improve with advances in vitreoretinal
surgical instrumentation and technique.
• Development of adjunctive pharmacotherapy should
enable further improvements in the future

69. References
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70. 8.West JF, Gregor ZJ. Fibrovascular ingrowth and recurrent haemorrhage following diabetic vitrectomy. Br J Ophthalmol 2000; 84:
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