[Age-related macular degeneration].

EPIDEMIOLOGICAL AND PATHOGENIC DATA: Age-related macular degeneration (ARMD) is the first cause of blindness in industrialized countries in patients over the age of 55. Its prevalence increases with age, affecting up to 25% of the population aged over 75. The pathogenesis of this disease is not well known. Not only aging, but also other varying degrees of genetic and environmental factors are implied.

METHODS

Precursors (first clinical signs of ARMD) can be observed on examination of the fundus: drusen (localized deposits of lipids and lipoproteins) and alterations in retinal pigment epithelium (RPE) (hypo- or hyperpigmentation). Two forms of complications are observed: atrophic (or "dry") and exudative (or "wet"). The atrophic form is defined by the presence of degeneration in the central RPE, choriocapillaris and photoreceptors, resulting from the enlargement and/or coalescence of small areas of peri-foveolar atrophy (or "geographic" atrophy). The exudative form, responsible for the majority of cases of blindness due to ARMD, is characterized by the appearance of choroidal new vessels, identifiable on fluorescein angiography and responsible for serous retinal detachment, edema and hemorrhage, leading to the destruction of the macular photoreceptors. FROM A THERAPEUTIC POINT OF VIEW: Treatment of the atrophic form is currently only palliative (visual aids and re-habilitation of low vision). Treatments of the exudative form having demonstrated their efficacy are laser photocoagulation and dynamic phototherapy with verteporfine, providing relative stabilization of visual acuity in around 2/3 of the eyes. Other treatments are under evaluation: anti-angiogenic treatments, surgical techniques (ablation of the new vessels, foveal translocation), new laser treatments (transpupillary thermotherapy, selective photocoagulation of the feeder vessels). Photoreceptor and pigment epithelium transplantations or implantation of microphotodiodes represent other long-term alternatives.