Age-Related Macular Degeneration

Kiran Panesar, BPharmS (Hons), MRPharmS, RPh, CPh

Disclosures

US Pharmacist. 2015;40(6):22-26. 

In This Article

Stages of ARMD

Early stages of ARMD are characterized by a macula that has yellowish subretinal deposits (drusen) and/or increased pigment. Patients with early ARMD have stable visual acuity for many years, and loss of vision is gradual.[5] Although there are various classification systems for ARMD, the Age-Related Eye Disease Study (AREDS) classification (Table 1) is most commonly used.[6]

Advanced ARMD causes a significant loss of vision. There are two types of ARMD: dry and wet.

Dry ARMD

The dry form of ARMD is also known as nonexudative, nonneovascular, or atrophic ARMD. This is the more common form of ARMD, seen in about 90% of cases.[7] Vision loss in dry ARMD is gradual and usually is associated with moderate visual impairment, as well as functional limitations including fluctuating vision, difficulty reading, and limited vision at night or under conditions of reduced illumination. Upon examination, the macula shows areas of depigmentation.[5]

Wet ARMD

Wet ARMD, which is also referred to as exudative or neovascular ARMD, accounts for about 10% of cases.[7] However, its presence usually indicates a more advanced disease state, and it is associated with rapid distortion and a sudden loss of central vision over a period of weeks to months.[2] A number of studies have demonstrated that, in patients with wet ARMD, the eyes have two times the expected prevalence of vitreomacular adhesion and are less likely to have a posterior vitreous detachment.[8] Fluid and exudate may accumulate underneath the retina in patients with neovascular ARMD, resulting in severe macular edema.[5,7] If left untreated, the neovascular membrane forms a big scar in the macular area, resulting in a sudden decrease in central vision.[7] Choroidal neovascularization (CNV) is an advanced stage of wet ARMD that can lead to the development of polypoidal choroidal vasculopathy. The condition progresses from drusen to the development of CNV, whereby the choriocapillaries cross Bruch's membrane and spread laterally within the planes of these lesions.[9]

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