Macular function impairment in eyes with early age-related macular degeneration.

PURPOSE: To study different aspects of macular function in eyes with early age-related macular degeneration (early AMD: drusen with or without retinal pigment epithelium alterations) and normal visual acuity, to obtain a complete evaluation of macular function impairment in early AMD and to study the relationship between macular function and the ophthalmoscopic signs of early AMD. METHODS: Forty-seven subjects with early 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 neovascular AMD in the fellow (nonstudy) eye (group 2). Thirty-six age-matched healthy subjects were used as controls. Thirty degree stereoscopic fundus photographs and fluorescein angiography were performed to grade macular lesions. Macular recovery function, central visual field sensitivity, spatiotemporal contrast sensitivity, and the Farnsworth-Munsell 100 hue test were used to study different aspects of macular function. RESULTS: Except for color vision, all macular function tests were significantly impaired in eyes of patients with early AMD compared to those in control subjects. No functional difference was found between groups 1 and 2. The increase in drusen number negatively influenced macular recovery function. Increasing drusen confluence reduced macular recovery function as well as central visual field sensitivity and some selected spatial frequencies of spatiotemporal contrast sensitivity. Geographic atrophy of the retinal pigment epithelium and focal hyperpigmentation reduced macular recovery function and contrast sensitivity at the highest spatial frequency. CONCLUSIONS: Macular recovery function central visual field sensitivity, and spatiotemporal contrast sensitivity are adequate and reliable indicators of macular function impairment in early AMD. Macular recovery function is the test that best reflects the ophthalmoscopic characteristics of early AMD because its deterioration parallels the worsening of typical fundus lesions. Function tests are valuable in the evaluation of patients with early AMD, particularly when interventional trials are planned.

The effect of external eye irradiation on choroidal circulation.

BACKGROUND: The effect of external beam radiation therapy (teletherapy) on the choroidal circulation is poorly known. Eyes irradiated with teletherapy represent a good model to study, without confounding factors, the pathophysiologic and clinical aspects of radiation-induced chorioretinal damage. This study used fluorescein and indocyanine green choroidal angiography to investigate the late effects of external eye irradiation on the choroidal circulation. METHODS: Fluorescein angiography and indocyanine green choroidal videoangiography were performed on patients with radiation retinopathy because of external eye irradiation for orbital and paranasal sinus malignancies. Patients were divided into two groups according to the treatment field (anterior unilateral or bilateral). RESULTS: Indocyanine green angiograms showed areas of choriocapillaris hypoperfusion in all eyes-unilateral or bilateral irradiation-affected by radiation retinopathy. Late indocyanine green choroidal staining was found in five eyes (28%) of the patients who received unilateral anterior irradiation. In the same group, nine eyes (52%) had signs of choroidal precapillary occlusion and four eyes (23%) had rubeosis iridis without retinal neovascularization. One case of subfoveal choroidal neovascularization was documented in the bilateral irradiation group. CONCLUSIONS: Radiation side effects are not limited to the retinal vessels but also involve choroidal circulation. The damage to the choroid is primarily vascular, and its clinical aspects depend on the treatment fields. Anterior irradiation may be a critical factor for the appearance of unusual rubeosis iridis and neovascular glaucoma.

Macular drusen and the sensitivity of the central visual field.

Macular drusen are one of the earliest signs of age-related macular degeneration but little information is available on the functional aspects of macular area in patients with drusen. To determine if drusen are associated with changes in central visual field sensitivity, one eye of each of 35 subjects (mean age 64.9 years) with bilateral drusen and visual acuity of 1.0 (20/20) underwent automated static threshold perimetry of the central 10 degrees. 16 normal subjects (mean age 65.8 years) were used as controls. 30 degrees fundus photographs were graded in a masked fashion for the clinical characteristics of drusen: type, size and number. The mean sensitivity (MS) of the central 10 degrees was significantly lower in eyes with drusen compared to normal eyes (p = .0001). After grading drusen eyes for size (> or = 63 mu) and type (presence of soft drusen), MS significantly deteriorated when large and soft drusen were present. These results suggest that central visual field sensitivity is precociously affected in eyes with drusen and that testing central visual field sensitivity may be useful as functional parameter in long term studies on the evolution of age-related macular degeneration.