MACULAR FUNCTION IMPAIRMENT IN EYES WITH EARLY AGE-RELATED MACULAR DEGENERATION

Purpose. To study different aspects of macular function in eyes with e arly age-related macular degeneration (early AMD: drusen with or witho ut retinal pigment epithelium alterations) and normal visual acuity, t o obtain a complete evaluation of macular function impairment in early AMD and to study the relationship between macular function and the op hthalmoscopic signs of early AMD. Methods, Forty-seven subjects with e arly AMD and visual acuity better than 20/25 in at least one eye were studied: 34 patients had bilateral early AMD (group 1), 13 had neovasc ular AMD in the fellow (nonstudy) eye (group 2). Thirty-six age-matche d healthy subjects were used as controls. Thirty degree stereoscopic f undus photographs and fluorescein angiography were performed to grade macular lesions. Macular recovery function, central visual field sensi tivity, spatiotemporal contrast sensitivity, and the Farnsworth-Munsel l 100 hue test were used to study different aspects of macular functio n. Results. Except for color vision, all macular function tests were s ignificantly impaired in eyes of patients with early AMD compared to t hose in control subjects. No functional difference was found between g roups 1 and 2. The increase in drusen number negatively influenced mac ular recovery function. Increasing drusen confluence reduced macular r ecovery function as well as central visual field sensitivity and some selected spatial frequencies of spatiotemporal contrast sensitivity. G eographic atrophy of the retinal pigment epithelium and focal hyperpig mentation reduced macular recovery function and contrast sensitivity a t the highest spatial frequency. Conclusions. Macular recovery functio n, central visual held sensitivity, and spatiotemporal contrast sensit ivity are adequate and reliable indicators of macular function impairm ent in early AMD. Macular recovery function is the test that best refl ects the ophthalmoscopic characteristics of early AMD because its dete rioration parallels the worsening of typical fundus lesions. Function tests are valuable in the evaluation of patients with early AMD, parti cularly when interventional trials are planned.