AGE RELATED MACULAR

DEGENERATION

DEFINITION

Macular degeneration, often age-related macular degeneration (AMD or ARMD), is a medical condition that usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina.

CHARACTERISTIC FEATURES Age : above 50 yrs - senile macular

degeneration

bilateral

CLINICAL TYPES

Non Exudative ARMD- mild to moderate gradual loss of vision central shadowing

Exudative ARMD-

rapidly progressivemarked loss of vision

PATHOPHYSIOLOGY-DRUSENS-FA

Degree of hyperfluorescence depends on: Extent of overlying RPE atrophy (window

defect) Amount of staining Lipid content

RISK FACTORS Heredity Nutrition Smoking Hypertension Exposure to sunlight Hyperopia Blue eyes Cataract

NON EXUDATIVE ARMD

Dry or geograhic

Accounts for 90% ARMD

atrophy of the retinal pigment epithelial layer

  vision loss through loss of photoreceptors (rods and cones) in the central part of the eye

LESIONS ON OPHTHALMOSCOPE Early : 1-Maular drusens-small to medium sized 2-Focal hyperpigmentation 3-Pale area of RPE atrophy

Intermediate : 1-drusens-large sized 2-sharply cirumscribed circular RPE atrophy

Advanced : 1-Enlarged atrophi areas 2- preexisting drusens disappear 3- visible larger choroidal vessels

Initial drusen and non-specific RPE changes

Late RPE (geographic) atrophy

EXUDATIVE ARMD

Wet or neovascular type

Accounts for 10%

due to abnormal blood vessel growth (choroidal neovascularization) in the choriocapillaris, through Bruch's membrane, ultimately leading to blood and protein leakage below the macula.

irreversible damage to the photoreceptors

and rapid vision loss if left untreated

LESIONS Pigment epithelial detachment (PED)

Choroidal neovascularization (CNV)

SIGNS OF PIGMENT EPITHELIAL DETACHMENT

Circumscribed, dome-shaped elevation

Sub-RPE fluid may be clear or turbid

SIGNS OF CHOROIDAL NEOVASULARISATION

Pinkish-yellow subretinal lesion with fluid

Subretinal blood or lipid

DIAGNOSIS

To see Amsler grid Snellen chart typial signs eluidated on slit-lamp

biomicroscopy Fundus flurescene angiography

Iodocyanine angiography Optical coherene tomography

FLUORESCEIN ANGIOGRAM

Hyperfluorescence from RPE window defect –Atrophic ARMD

ICG ANGIOGRAM OF PIGMENT EPITHELIAL DETACHMENT

Early, well-defined hypofluorescence

Later, thin surrounding hyperfluorescent ring No increase in size of lesion

MANAGEMENT-NON EXUDATIVE No effective treatment Measures tried- 1-dietary supplements & antioxidants 2-smoking cessation 3-Advice amsler grid regularly 4-low viosion aid

MANAGEMENT-EXUDATIVE Intraviteral anti-VEGF therapy Bevacizumab Ranibiuzumab Pegaptanib Photodynamic therapy-PDT Transpupillary thermotherapy Double frequeny YAG 532NM

photocoagulation Surgical treatment