Macular Degeneration: Loeffler KU

Fleckenstein M, Charbel Issa P, Helb HM, Schmitz-Valckenberg S, Finger RP, Scholl HP, Loeffler KU, Holz FG. · Department of Ophthalmology, University of Bonn, Bonn, Germany. · Invest Ophthalmol Vis Sci. · Pubmed #18487363 No free full text.

Abstract: PURPOSE: To describe morphologic variations in outer retinal layers in eyes with atrophic age-related macular degeneration (AMD) using high-resolution, spectral-domain optical coherence tomography (SD-OCT). METHODS: SD-OCT scans were obtained with a combined confocal scanning laser ophthalmoscope (cSLO) and SD-OCT for simultaneous tomographic and topographic in vivo imaging. A total of 81 eyes of 56 patients (mean age, 77.8 +/- 7.4 years) with geographic atrophy (GA) were examined. Morphologic alterations were analyzed and classified in the perilesional zone, at the junction between GA and nonatrophic retina, and in the atrophic area itself. RESULTS: In the perilesional zone, distinct morphologic alterations included elevations of the outer retinal layers, thickening, and spikes of the outer hyperreflective band as well as clumps at different neurosensory retinal levels. At the junction, highly variable transitions of the outer retinal layers were present with different degrees of loss of the normal hyperreflective bands. Within the actual GA, hyperreflective clumps at different retinal levels, segmented plaques of the outer band and elevations with variable reflectivity were visualized. CONCLUSIONS: SD-OCT imaging in eyes with GA revealed a wide spectrum of morphologic alterations, both in the surrounding retinal tissue and in the atrophic area. These alterations may reflect different disease stages or, alternatively, heterogeneity on a cellular and molecular level. Longitudinal studies using in vivo SD-OCT imaging may allow evaluation of the relevance of these phenotypic changes as potential predictive markers for the progression of disease (i.e., enlargement rates of GA over time) and may be used for monitoring of future therapeutic interventions.

Loeffler KU, Sastry SM, McLean IW. · Department of Ophthalmology, University of Bonn, Bonn, Germany. · Curr Eye Res. · Pubmed #11821983 No free full text.

Abstract: PURPOSE: To evaluate whether ocular changes indicating an increased exposure to UV irradiation are associated with the development of age-related macular degeneration (ARMD). METHODS: Using histology, we have investigated a possible association of ocular changes that might be attributed to actinic damage, namely pinguecula and scleral plaque, with findings of both atrophic and disciform ARMD. A total of 74 eyes, could be used for evaluation. RESULTS: Features of ARMD were present in 36 eyes (11 with disciform degeneration and 25 with an atrophic form). A pinguecula was identified in 36 eyes (small in 22 eyes, large in 14 eyes), and a scleral plaque was seen in 5 eyes. While scleral plaque showed an association with ARMD, there was no significant association between pinguecula and ARMD. CONCLUSIONS: Our results support the concept of solar radiation having an effect on the development of ARMD but also indicate that it is a multifactorial disease.

Sahm M, Loeffler KU, Seifert P, Spitznas M. · Department of Ophthalmology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. · Graefes Arch Clin Exp Ophthalmol. · Pubmed #11450495 No free full text.

Abstract: BACKGROUND: Ultraviolet radiation is thought to play a causative role in various ocular diseases such as macular degeneration, cataract, and possibly melanomas. Since most of the energy is absorbed by pigmented cells, the aim of this study was to examine and compare the reactions of different ocular melanocytic cells to ultraviolet light in vitro. MATERIALS AND METHODS: Bovine iris melanocytes, choroidal melanocytes, iris pigment epithelial cells, and retinal pigment epithelial cells were isolated and cultured. Semiconfluent cultures were exposed to ultraviolet radiation (280-380 nm). Cell number and melanin content were measured 10 days after radiation. Selected samples were examined by transmission electron microscopy. RESULTS: Following irradiation with ultraviolet light for 30 s, 60 s, and 120 s, the number of cells in culture decreased markedly. In contrast, total melanin content in the cultures of iris melanocytes, choroidal melanocytes, and iris pigment epithelial cells did not decrease despite the reduced number of cells. This finding suggested an increase in melanin per cell. However, the increase in average melanin content observed was not due to melanogenesis, because treatment with the melanogenesis inhibitor alpha-methyl-p-tyrosine did not reduce the melanin content of the cultures and electron-microscopic examination showed no morphological evidence of increased melanogenesis. CONCLUSION: In vitro, there was no convincing evidence of ultraviolet radiation-induced melanogenesis in ocular pigmented cells. Thus, it seems that ultraviolet radiation is a selection factor: more densely pigmented cells survive the treatment better than less pigmented cells.