Upload
thessaloniki-international-vitreo-retinal-summer-school
View
199
Download
1
Embed Size (px)
DESCRIPTION
http://www.tvrs.gr/
Citation preview
Surgical Management of Diabetic Retinopathy
Thomas Aaberg Jr. M.D.Retina Specialist of Michigan
Michigan State University
Management of complications from Proliferative diabetic
retinopathy
Pars plana vitrectomy is the procedure of choice for vitreous hemorrhage and tractional retinal detachment
Pars plana vitrectomy-Indications
Persistent vitreous hemorrhage Tractional/combined rhegmatogenous
retinal detachment Premacular hemorrhage Bridging retinal fibrosis Persistent diabetic macular edema
Pathogenesis Review:Surgical Intervention for TRD
Hypoxia and angiogenic factors, eg. VEGF
Neovascular and fibrovascular proliferation that extends from the retina into the vitreous cavity
Cycle of proliferation and regression along the posterior margin of capillary non-perfusion
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 814
Pathogenesis Review:Surgical Intervention for TRD
Neovascular proliferation usually begins: at the optic nerve along temporal
vascular arcades mid-periphery at the
posterior margin of capillary non-perfusion
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 814
Pathogenesis Review:Proliferative Diabetic Retinopathy
Initially “bare” Later, fibrous tissue appears Vitreoretinal adhesions form Cycle of proliferation and
regression
Pathogenesis Review:Surgical Intervention for TRD
Growth of fibrovascular tissue is dependent on posterior vitreous surface Changes in vitreous occur, often resulting
in partial posterior vitreous detachment Vitreous typically remains attached at
anterior retina/vitreous base and at each area of fibrovascular proliferation
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 815
Pathogenesis Review:Surgical Intervention for TRD
Contraction of fibrovascular tissue growing along posterior vitreous surface can cause vitreous changes and antero-posterior traction.
In the absence of vitreous separation, widespread adhesions to the retinal surface may develop
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816
Pathogenesis Review:Surgical Intervention for TRD
Contraction forces may lead to: Hemorrhage into vitreous
gel or preretinal space Tractional retinal
detachment (TRD) Distortion of retina/macula Antero-posterior and
tangential traction
Traction on the optic nerve Retinal tears
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816
Surgical Management
A review of the past,And where we are today.
Surgical Intervention for TRD
PurposeReverse pre-existing complications
causing visual lossAlter course of retinopathy and remove
posterior vitreous surface
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816
Surgical Intervention for TRD
Posterior vitreous surface is of great importance in pathogenesis and complications of proliferative diabetic retinopathy and must be addressed during vitreous surgery
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816
Surgical Intervention for TRD
Surgical objectivesRemove visually significant opacitiesExcise posterior hyaloidRemove and/or segment preretinal or
epiretinal fibrovascular tissue Identify & treat retinal breaksHemostasisPanretinal photocoagulationTamponade as needed
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816
DDiabetic
RRetinopathy
VVitrectomy
SStudyA MultiA Multi--Center Collaborative Clinical TrialCenter Collaborative Clinical TrialSupported by Contracts fromSupported by Contracts fromThe National Eye Institute The National Eye Institute
PortlandPortland
San FranciscoSan Francisco
Los AngelesLos Angeles
MinneapolisMinneapolis
MadisonMadisonChicagoChicago
MilwaukeeMilwaukee
DetroitDetroit
AlbanyAlbanyBostonBoston
New YorkNew YorkPhiladelphiaPhiladelphia
BaltimoreBaltimore
DurhamDurham
AtlantaAtlanta
MiamiMiami
More rapid recovery of useful vision (important if fellow eye
has poor vision)
Greater chance for recovery of good vision (at least Type I DM
who were younger and had more severe PDR)
Suggestive increase in frequency of NLP in Type II and mixed
DM groups (older patients with less PDR)
Early Vitrectomy in Eyes with Recent Severe Diabetic Vitreous
Hemorrhage
Diabetic Retinopathy Vitrectomy Study
Eyes (n = 370) with fibrovascular proliferation and 20/400 or better VAResults: 20/40 or better VA at 4 yearsEarly surgery: 44% eyesDeferred surgery: 28% eyes
Early Vitrectomy for Severe Proliferative Diabetic Retinopathy in Eyes with Useful Vision. Results of a Randomized Trial--. Diabetic Retinopathy Vitrectomy Study (DRVS) report #3. Ophthalmol 1988; 95(10):1307-1320
Results of Vitrectomy for diabetic TRD involving macula
Improved VA: 26% - 72% cases
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 824-825
Results of Vitrectomy for combined diabetic TRD and rhegmatogenous
detachment
Retinal reattachment: 80%
Improved Vision: 50%
Rates of success can vary based on patient population, pathology and access to health care
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 825Photo courtesy of Edgar L. Thomas, MD
Diabetic Vitrectomy: Advanced Surgical Techniques
Step 1: Pre-operative Care
Advanced Diabetic Vitrectomy Begins Pre-operatively
Maximize systemic health/stability Concentrate on renal statusWork with primary care physician,
endocrinologist, nephrologist Properly educate patient Pathophysiology Extent of disease Proper patient expectations
Immediate Pre-Operative Anti-VEGF … Yes or No Literature supporting
both pro and con Personally I use IF: I know the patient will be
compliant I know the surgical case is
a GO There is active NV not just
traction or hemorrhage.
Why be concerned about anti-VEGF use?
Immediate concern: Delayed surgery may
lead to progressive severe vitreoretinal contraction
Longer term concern: Rebound proliferation
once anti-VEGF effect dissipates.
Step 2: Surgical Planning
Game changing advances in surgical instrumentation.
Surgical Planning/Decisions
Anesthesia: General vs Local Gauge: 20 vs 23 vs 25 vs 27 Lens disposition Pseudophakic Phakic Unencumbered view of pathology Compromises view Keep or remove the lens with or without an IOL
Bimanual versus “uni”-manual approach
Chosen Surgical Gauge was largely dictated by number of available
instruments Vitrectomy probesHigh speed cuttersDifferent edge profiles
20 gauge
20 gauge
25 gauge
25 gauge
Advances in Surgical Instrumentation20 gauge
Forceps
Advances in Surgical Instrumentation20 gauge
Scissors
Advances in Surgical Instrumentation20 gauge
Illuminated instruments
Currently nearly all instruments are available in 25 and 23 gauges
Photos courtesy of E.Thomas, MD and Alcon
25 gauge - system
Advances in Surgical Instrumentation25 gauge - system
Vitrectomy cutter
Trochar canula inserter
Canula
InstrumentsPhotos courtesy of E.Thomas, MD and Alcon
Advances in Surgical Instrumentation
25 gauge
Forceps
Scissors
Picks
Illuminated instrumentation and chandeliers … a critical advance
20 gauge chandelier and set-up Illuminates one area preferentially
Photos courtesy of Synergetics and James Andrews
Illuminated instrumentation and chandeliers … a critical advance
Photos courtesy of Synergetics and James Andrews
29-gauge chandelier and Xenon light source
Another critical surgical advance:Perfluorocarbon Liquid
Properties Non-toxic Clear liquid High density Low viscosity; easy
to inject and remove Visualize liquid
interface Volatility
Perfluorocarbon Liquid: The Third Hand
Benefits Keep heme off
macular region Assist in dissection
and removal of posterior hyaloid Stabilize the retina
during membrane dissection and delamination
Perfluorocarbon Liquid: The Third Hand
Benefits Identify residual
posterior hyaloid and membranes Drain subretinal
fluid through peripheral break Allow for
controlled retinotomies
Perfluorocarbon Liquid: The Third Hand
Complications Subretinal PFC may pass through posterior
breaks with traction Residual PFC at end of surgerymore common in hemorrhages
Advances in Surgical Instrumentation:Wide Angle Viewing
Contact AVI Volk
Noncontact BIOM Merlin
Advances in Surgical InstrumentationWide Angle Viewing
Benefits Improved panoramic visualizationMore easily visualize extent of tractional forces Improved management of peripheral retinal
pathology Bimanual surgery Enhances phakic fluid air exchange and
placement of scatter laser treatment
Step 3: Surgical Techniques
Single Instrument Vitrectomy
Bimanual Surgery
Endo-illumination by chandelier Single chandelier Dual chandelier Illuminated infusion cannula Illuminated instruments
Surgical Intervention for TRD Surgical TechniquesVitrectomyRemove core vitreousIncise posterior vitreous surfaceRelieve A-P traction
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816-817
Surgical Techniques for surface membranes
SegmentationDivide fibrovascular tissue
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 816-824
Surgical Techniques for surface membranes
En blocUse some posterior vitreous A-P traction
to elevate edge of fibrovascular tissue
Diagrams from Gardner TW and Blankenship GW. Proliferative diabetic retinopathy: principles and techniques of surgical treatment. In Ryan SJ ed. Retina, Bert Glaser, ed. Vol 3 Surgical Retina. St. Louis, 1994, Mosby, p. 2420-2421
Surgical Techniques for surface membranes
Modified En Bloc Delamination After releasing
pathology from the vitreous base, use an instrument to induce A-P traction and create a cleavage plane.
Surgical Techniques for surface membranes
Modified En Bloc Delamination Identify cleavage plane Scissors to transect
fibrovascular bridges Hemostasis Endodiathermy or
bipolar diathermy PRP Tamponade as needed
Hemostasis Critical in the diabetic
patient Fibrin deposition Secondary membranes Immediate post-
operative vitreous hemorrhages
Tactics Raise intraocular
pressure Intraocular diathermy Intraocular Thrombin
Surgical Intervention for TRD
First-Is it necessary? Break No-breaks
Second-Which agent? Air SF6 C3F8 Silicone oil Monocular Aphakia
Tamponade
Factors relevant to tamponade agent Extent of pathology Patient
compliance/physical abilities Lens Status Monocular vs
Binocular Travel
Surgical intervention for TRD
Major ComplicationsRetinal tearsRetinal detachmentPVRCataractEndophthalmitis
Vitreous Surgery. In Michels RG, Wilkinson CP and Rice TA eds. Retinal Detachment. St. Louis, 1990, Mosby, p. 825
Management of Tractional Retinal Detachment
Summary Tractional Retinal Detachment Pathogenesis
Surgical intervention Surgical objectives/techniques Progress in instrumentation Perfluorocarbon liquidsWide angle viewing High speed vitrectomy 25 gauge - sutureless
Pharmacotherapeutic interventions Plasmin Vitrase
Premacular hemorrhage Pre-Operative Vision = CF
Post vitrectomy Vision = 20/30