Treatment of subfoveal choroidal neovascularisation in age related macular degeneration: focus on clinical application of verteporfin photodynamic therapy

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Abstract
Age related macular degeneration (AMD) is a degenerative disease usually occurring in people over the age of 50 years. Macular involvement can cause vision impairment and result in legal blindness due to atrophic or neovascular complications.1 The definition of specific lesions associated with AMD has led to classifications of the condition and its severity.1 The “dry” or non-neovascular form of AMD is characterised by drusen or abnormalities of the retinal pigment epithelium (RPE) such as atrophy, or hypopigmentation or hyperpigmentation. “Wet” or neovascular AMD is manifested by choroidal neovascularisation (CNV).2 The prevalence of non-neovascular AMD is greater than that of neovascular AMD. However, 10–20% of patients with non-neovascular AMD progress to neovascular AMD.34 Severe vision loss usually occurs when CNV extends under the centre of the foveal avascular zone (subfoveal CNV).5 Neovascular proliferation from the choriocapillaris extends through Bruch's membrane, invades the space under the RPE and leaks serous fluid, including lipid or blood, into this space.6 This neovascular process is associated with the development of fibrous tissue which replaces the normal architecture of the outer retina, often leading to severe, irreversible loss of central vision.7 Neovascular AMD, although present in less than 20% of all patients with AMD, is responsible for approximately 90% of cases with severe vision loss.8 It occurs in up to 200 000 individuals in the USA each year,9 with approximately 500 000 new cases throughout the world. Without treatment, most affected eyes have poor central vision (⩽20/200) within 2 years.10 The prevalence of AMD has been estimated in several epidemiological studies and ranges from 2% to over 10%, depending on the working definition of AMD, the grading system used, and the age and environment of the study population.3 All the studies, however, point to the …