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