ARMD - Investigations

ARMD :Investigations & Management : 

ARMD :Investigations & Management Dr Gyanendra Lamichhane Lumbini Eye Institute Bhairahawa, Nepal

Introduction : : 

Introduction : Clinical examination alone usually sufficient to confirm the diagnosis For clinical subtle macular abnormalities especially sub-retinal fluid - stereoscopic slit-lamp biomicrscopy with a contact lens.

Fundus Fluorescein Angiography : : 

Fundus Fluorescein Angiography : If suspected of CNV. Not a useful screening test for eyes having drusen or geographic atrophy alone.

Drusen : : 

Drusen : appear as a window defect from early phase - Hard drusen : readily demonstrated on FFA. fluorescing brightly in early phase. fading soon after the background choroidal fluorescence. - Soft drusen : larger with less sharply defined edges. tends to become confluent. shows greater variation in size & shape. FFA - fill more slowly &lot brighter. remain fluorescent for a longer time.

Geographic Atrophy : : 

Geographic Atrophy : FFA – diffuse window defect . pigment clumping within. micro-reticular pattern.

Serous RPE detachment : 

Serous RPE detachment uniform bright hyperfluorescence in early phase. continues into late phase.

Choroidal Neovascularization : 

Choroidal Neovascularization FFA – early hyper fluorescence of new vessels, deep to the retina . leakage during transit phase. progressive enlargement of leakage in size and intensity. late pooling of dye into sub- RPE /sub-retinal space.

Choroidal Neovascularization : : 

Choroidal Neovascularization : Types based on FFA : Well defined / Classical. Poorly defined / Occult.

Well defined CNV : : 

Well defined CNV : only 10 - 15 % progressive focal area of sub-retinal hyperfluorescence noted during /before A V phase . lacy pattern, with initial well defined borders. later irregular – leakage & diffusion into sub-retinal space.

Occult CNV : : 

Occult CNV : more common. early hyperfluorescence . not well defined . fluorescence blocked by blood , SRF diffuse ooze is seen . late leakage – typical (source- not visible).

Classification on FFA : Acc. to location : 

Classification on FFA : Acc. to location Subfoveal – CNV extends underneath the centre of FAZ Juxtafoveal – edge of CNV extends within 1-199 μm of the centre of FAZ Extrafoveal – extends no closer than 200 μm from centre of FAZ.

Fibrovascular PED : : 

Fibrovascular PED : irregular elevation of RPE which neither bright nor as discrete as classical CNV mid- phase stippled hyperfluorescence. late leakage and staining

Indocyanine Green Angiography : : 

Indocyanine Green Angiography : Infra red based digital imaging technique Advantages over FFA : Highly protein bound dye , leaks slowly from choriocapillaries. Greater degree of penetration through RPE, blood Uses – detection of occult CNV detection of recurrent CNV following Laser

Angiographic features : : 

Angiographic features : Focal /Hot spots : <1DD in size , well delineated Placoid hyperfluorescence : occult CNV >1DD may/may not well defined and not obscured by h’age Combination

Serous RPE detachment- : 

FFA ICG angiography Serous RPE detachment-

Serous RPE detachment- : 

FFA ICG angiography Serous RPE detachment-

Confocal scanning Laser fundus fluorescein with ICG : : 

Confocal scanning Laser fundus fluorescein with ICG : Method – 5oo mg of Fluorescein + 25 mg ICG (mixed together ) Heidelberg Retina Angiograph. Argon laser beam (488 nm) + diode laser beam (795 nm) delivered by single mode fibers . emission – 500 –700 nm and above 800nm. digital image

Confocal scanning Laser fundus fluorescein with ICG : : 

Advantages : high contrast image during all phases accurate correlation of findings low retinal irradiance less time consuming Confocal scanning Laser fundus fluorescein with ICG :

ARMD (DRY ) - management : 

ARMD (DRY ) - management AREDStudy - high doses of vitamins & zinc ( reduced risk of developing visual loss ) Criteria : 1 drusen > 125 μm in diameter/non- central geographic atrophy. drusen <125 μm but >63 μm area covered >360 μm dia. circle of soft drusens. If no soft drusens, area covered >656 μm. Patients with advanced ARMD / visual loss due to ARMD in other eye.

ARED Study : 

ARED Study Dosage : Vit. C 500mg Vit. E 400IU Beta-carotene 15mg Zinc as zinc oxide 80 mg Copper 2mg as cupric oxide Dosage is 5 times usual intake of Vit.C & Zinc 13 times RDA of Vit A Contraindication : Smokers/former smokers Lasers – faster reabsorption of drusen

ARMD (WET ) - management : 

ARMD (WET ) - management Treatment modalities : Photocoagulation Photodynamic therapy Surgical Radiation

Photocoagulation : MP Study : 

Photocoagulation : MP Study CNV based on signs & symptoms. Goal of Rx :To decrease risk of additional severe VA loss Argon blue-green (488-514 nm ) Argon green (614 nm) Krypton red (647 nm)

Photocoagulation : : 

Photocoagulation : Indications : Classic CNV with welldefined borders. Occult CNV (with classic associated , entire lesion well defined ) Laser might not be indicated Only occult CNV Boundaries of entire CNV not well defined

Preparation of patient : : 

Preparation of patient : Information Not a cure regarding side effect – permanent blank area increased distortion/ decreased VA FFA not older 72 hrs ( ideal < 24hrs).

Extrafoveal CNV : : 

Extrafoveal CNV : Location : foveal edge of CNV 200-2500 μmfrom FAZ centre. Pattern : cover CNV contiguous blockage , 100 μm beyond. recurrence : 54% at 5yrs

Juxta foveal : 

Juxta foveal Location : foveal edge of CNV 1-199 μm from FAZ centre. If CNV blocked by blood Pattern : non foveal side- cover CNV contiguous blockage , 100 μm beyond. foveal side - cover CNV If CNV >100 μm from FAZ + blood - cover blood contiguous blockage , 100 μm beyond. recurrence : 76% at 4yrs

Sub foveal : 

Sub foveal new : </= 3.5 MPS disc area. pattern : cover CNV contiguous blockage , 100 μm beyond. recurrence : 51% at 2yrs Recurrent :</= 6 MPS disc area. pattern : cover CNV contiguous blockage , 100 μm beyond, re-tt of laser scars . recurrence : 48% at 2yrs Rx results in immediate loss of vision.

Recurrence : : 

Recurrence : risk of recurrence is greatest – fellow eye – active CNV / scarring. incomplete treatment. less intense burns. cigarette smokers. lesion proximity to FAZ centre.

Recurrence : : 

Recurrence : Signs : decreased VA. persistence / increased SRF. new areas of hypopigmentation at tt scar edge. new late hyperfluorescence at tt scar edge. adjacent stippling of RPE on FFA. contiguous RPE detachment. new flecks of sub-retinal blood /lipid.

Photodynamic therapy : PDT/OPT : 

Photodynamic therapy : PDT/OPT Rx of classic sub-foveal CNV. Verteporfin –a light activated drug attaches to lipoproteins present in actively proliferating capillaries of CNV Laser causes photoactivation Verteporfin converts oxygen into highly energized oxygen singlet that damages endothelial cells of CNV Verteporfin (6mg/m2 of body surface)

Slide 33: 

15 min later a diode laser at 689 nm in slit lamp delivered 50 J/cm by continuous application of laser at 600 mw/cm2 for 83seconds. Treatment spot size was1000 μm larger than GLD Avoidance of direct sunlight for 48 hrs Verteporfin therapy reduces the risk of moderate to severe vision loss

Surgical : : 

Surgical : Full macular translocation with 360 0 retinotomy : Rx of sub foveal CNV

Radiotherapy : : 

Radiotherapy : photon therapy with EBR – sub foveal CNV. Dosage – 14.4 Gy (with 8 Mv photons ) in 8 fractions with 1.8Gy /day field size – 5.5 x 4.5 cm Drawback – enlargement of NVM 5-7 times

Newer modalities : : 

Newer modalities : Limited macular translocation followed by laser , with transposition of rectus muscles – for small , well defined subfoveal CNV. also viable for pt. already undergone PDT Intra vitreal injection of rt-PA ( recombinant tissue plasminogen activator), expansile gas SF6 for submacular h’age . Perfusion treatment trails – alter blood flow .

Newer modalities : Dry : 

Newer modalities : Dry Rheopheresis : elimination of high mol. wt. proteins from plasma. helps by reducing blood viscosity   RBC , platelet aggregation  impovement of microcirculation  recovery of retinal function.

Rehabilitation : : 

Rehabilitation : Patient education – importance of routine central vision testing Amsler grid – not sensitive and specific. Sunglasses. Low visual aids – hand held magnifiers large print reading material bright illumination CCTV Family education.

Thank You ! : 

Thank You !