DIABETIC RETINOPATHY DEMYSTIFIED

Dinesh mittal SONALEE MITTAL

DRISHTI THE VISION EYE HOSPITAL , VIJAYNAGAR INDORE

DINESH MITTAL

SONALEE MITTAL

Diabetic Retinopathy remains the leading cause of blindness among 25 and 75 years of age .

Diabetic Macular Odema the leading cause of decrease in

vision in Diabetic Retinopathy

•DR is a microangiopathy of retinal vasculature . •Earliest change thickening of basement membrane & loss of pericyte .

MICOANEURYSMS • hypercellular saccular outpoucings of cappilary wall

• deep red dots • first visible clinical sign of DR

sharply demarcated extravascular deposits of lipid material resultIng from spillage and incomplete resorption of lipoproteins .

often present at border between edematous & non edematous retina .

they may exist as circinate ring pattern around the

Hard exudates

Progressive capillary closure and resulting retinal ischaemia leads to

intraretinal microvascular abnormalities ( IRMA )

intraretinal haemorrhages and venous abnormalities ( eg venous beading )

Cotton wool spot

small white patches with wispy border

ischaemic area affecting nerve

fiber layer.

retinal thickening of the posterior pole and detected by slit lamp biomicroscopy or optical coherence tomography (OCT )

Diabetic macular odema ( DME )

3 zone of thick retina one disc area or larger any part of which is with in one disc diameter of center of macula

ETDRS defines CSME

1 thickening of retina at or with in 500 µm of center of macula 2 hard exudates at or with in 500 µm center macula with thick adjacent retina

Proliferative diabetic retinopathy ( PDR )

PDR formation of new vessels and fibrotic tissue on retina and optic disc contraction of fibrous tissue lead to tractional retinal detachment and viterous haemorrhage .

PDR with HRC s• NVD equal to or greater than 1/ 4 to 1/3 disc area • any amount of NVD with fresh vitreous / pre retinal haemorrhage • NVE equal to or greater than ½ disc area with fresh viterous /pre retinal haemorrhage .

Evaluation

• Previous history of diagnosis or treatment if any should be taken thoroughly. • Comprehensive eye examination

including VISUAL ACUITY , IOP measurement , • slit lamp examination of anterior

segment and dilated funduscopic examination

Evaluation• ophthalmoscopy in a dilated pupil

remains the standard for clinical diagnosis and further classification . • posterior pole examination is best

done with slit lamp biomicroscopy with accessory lenses .• imaging modalities commonly used

in the management are fundus photography , FA & OCT

OCT and FA are the most useful investigations in DME

• Confirm presence macular edema • Know type of macular edema • Assess macular thickness• Know response to intravitreal

pharmacotherapy• For follow up and documentation

OCT role in DME

FA role

•Type of leak focal or diffuse •Rule out macular ischaemia

Increasingly OCT is being used for evaluation of macular edema . Spectral domain ( SD OCT ) has replaced time domain OCT ( TD OCT ) .

Diabetic macular odema• Slit lamp biomicroscopy , color fundus

photography or ophthalmoscopy may not be able to detect mild DME . Here OCT is very helpful in measuring central foveal thikness.

• OCT has become gold standard in monitoring

the progression and treatment response in DME

• give micrometer sensitive measurements in central retinal thickness.

classification

• Mild non proliferative diabetic retinipathy

( NPDR ) Few microaneurysms or haemorrhages may be present .

classification

•Moderate NPDR Haemorrhages , microaneurysms , cotton wool spots ,

venous beading or IRMA may be present

.

classification

• Severe NPDR 4-2-1 rule Any one of following three features is considered diagnostic of severe NPDR all 4 quadrants contain severe intra retinal haemorrhages/ microaneurysms venous beading in 2 or more quadrants . IRMA in at least 1 quadrant .

PROLIFERATIVE DIABETIC RETINOPATHY

Early PDRNew vessels and criterion not met for high risk PDR PDR with HRCs• NVD ≥ than ¼ to 1/3 disc area.• NVD any amount with vitreous or pre retinal haemorrhage .• NVE ≥ than ½ disc area with fresh vitreous or pre retinal haemorrhage

Management•Modification of systemic risk factors • Intensive control of blood sugar• Control of blood pressure• Lowering of lipid levels• Exercise and food habbits

Management of DRPDR with HRCs

DRS study

do PRP pan retinal Photocoagulation

Severe NPDR & early PDR

ETDRS STUDY

consider for PRP

Early and mod NPDR

no PRP , regular follow up

PRP protocol•ETDRS ( early treatment diabetic retinopathy study ) protocol for full scatter laser provides useful guidelines •Size of burn 500 µm•Time .1 second

PRP protocol

•Intensity argon laser burn of moderate intensity

•Distance between spotsplaced one half to one burn apart

•Sittings divided between 2 or more sittings.

Management of macular odema

• If thickening involves centre of fovea then treat other wise wait .

• ETDRS recommends treatment if CSME is there. CSME

DRCR .net protocol Itreat centre involving DME with intravitreal inj of anti vegf agents till the macula is relatively dry followed by focal laser .

RANIBIZUMAB ( LUCENTIS ) .3 mg in .05 ml OrBEVACIMIZUMAB ( AVASTIN) 1.25mg in .05 ml.

• to reduce the burden and cost of injections usually three intravitreal anti vegf injections are given and then switched to as required PRN dosing .one can add intravitreal injection Triamcinolone 1mg / .025 ml

DRCR .net protocol I intravitreal anti vegf agents with early or deferred laser

Superior Over

laser alone

laser with steroids

steroids alone

or

or

DRCR .net protocol T

• all the three anti vegf agents RANIBIZUMAB , BEVACIMIZUMAB & AFLIBERCEPT are effective in management of DME . •RANIBIZUMAB is slightly better than BEVACIMIZUMAB but latter is more economical

Role of steroids in DME •Retisert , illuven, ozurdex dexamethasone implant & triamcinolone • ( 1mg and 4 mg ) are inferior to laser or intravitreal anti vegf agents

Role of steroids in DME • Intravitreal steroids has main complication of cataract and glaucoma .• In pseudophakic patients IV TA plus laser benefit is comparable to IV ANTI VEGF agents and superior to that seen in laser group

Modified ETDRS focal / grid laser protocol as used by DRCR .net

•Direct treatment of leaking microaneurysms in area of retinal thickening 500 to3000 µm centre of macula .• Spot parameter 50 µm , barely visible and .05 to .1 sec burn duration .

Grid treatment •500 to 3000 µm superiorly , nasally and inferiorly •500 to 3500 µm temporally from macular centre .•No burn in 500 µm of optic disc •Burn parameter two visible burns width apart

 

Pt. of PDR with HRCs with DME involving centre or having CSME

focal or grid laser followed by PRP .

Give intravitreal anti VEGF agents

Pt. of PDR with HRCs with DME involving centre or having CSME

GRID

PRPinjection