AGE-RELATED MACULAR DEGENERATION (AMD) 1. Drusen 2. Drusen and AMD 3. Atrophic AMD 4. Exudative AMD Pigment epithelial detachment (PED) Choroidal neovascularization (CNV)

Drusen Histopathology Hard Soft Larger, ill-defined spots Small well-defined spots May enlarge and coalesce Usually innocuous Increased risk of AMD

`` FA of drusen Degree of hyperfluorescence depends on: Extent of overlying RPE atrophy (window defect) Amount of staining Lipid content

Drusen and AMD - progression Atrophic AMD Exudative AMD

Atrophic AMD Progression Initially drusen and non-specific RPE changes Late RPE (geographic) atrophy

Atrophic AMD Fluorescein angiogram Management Hyperfluorescence from RPE window defect Low-vision aids if appropriate

Signs of Pigment epithelial detachment Sub-RPE fluid may be clear or turbid Circumscribed, dome-shaped elevation

FA of pigment epithelial detachment Early, well-defined hyperfluorescence Progressive increase in hyperfluorescence No increase in size of lesion

ICG angiogram of pigment epithelial detachment Early, well-defined hypofluorescence Later, thin surrounding hyperfluorescent ring No increase in size of lesion

Possible subsequent course of PED Spontaneous resolution Geographic atrophy CNV RPE rip

Choroidal neovascularization (CNV) Less common than atrophic AMD but more serious Metamorphopsia is initial symptom Most lesions are not visible clinically Suspicious clinical signs Subretinal blood or lipid Pinkish-yellow subretinal lesion with fluid

Angiographic classification of CNV Well-defined (classical) Occult Extrafoveal > 200 m from centre of FAZ Poorly defined Juxtafoveal < 200 m from centre of FAZ Obscured by PED, blood or exudate Subfoveal - involving centre of FAZ

FA of classical CNV Very early ‘lacy’ filling pattern Leakage into subretinal space and around CNV Late staining

ICG angiogram in PED with occult CNV PED is hypofluorescent CNV is hyperfluorescent (hot spot)

Possible subsequent course of CNV Haemorrhagic sensory and RPE detachment Subretinal (disciform) scarring Massive subretinal exudation Exudative retinal detachment

Potential indications for laser treatment of CNV Classic extrafoveal CNV on FA Occult extrafoveal CNV on ICG Pre-treatment FA of classic CNV

Technique of laser photocoagulation of CNV Perimeter is treated with overlapping 200 m (0.2-0.5 sec) burns Entire area is covered with high energy burns Late staining around margin is normal Lack of leakage following successful treatment

Results of laser photocoagulation of CNV Initial risk of severe visual loss reduced by over 50% Frequent subsequent recurrence with subfoveal involvement Recurrence of CNV several months after initially successful treatment