Macular Degeneration: Roth F

Eter N, Bindewald A, Roth F, Holz FG. · Augenklinik, Universität, Bonn. · Ophthalmologe. · Pubmed #15459788 No free full text.

Abstract: Optical coherence tomography (OCT) represents a fast and noninvasive examination technique that generates two-dimensional sections of the posterior pole in vivo. Although this method is now widely applied in the diagnosis of various heterogeneous macular diseases, its role in patients with age-related macular degeneration (AMD) is less well established. OCT allows for quantitative as well as qualitative assessment of various AMD phenotypes. Qualitative assessment comprises the evaluation of intra- or subretinal fluid, intraretinal cystoid spaces, and retinal pigment epithelial detachments. However, together with the clinical findings and fluorescence angiography, it can provide useful additional information including monitoring of treatment effects.

Roth F, Bindewald A, Holz FG. · Department of Ophthalmology, University of Bonn, Ernst-Abbestrasse 2, 53127 Bonn, Germany. · Graefes Arch Clin Exp Ophthalmol. · Pubmed #15309554 No free full text.

Abstract: PURPOSE: To review current knowledge of key pathogenetic pathways in age-related macular disease (AMD). METHODS: Experimental evidence and clinical observations are reviewed. RESULTS: A number of common downstream pathophysiologic pathways appear to be relevant in AMD manifestations irrespective of primary heterogeneous etiologies. These include sequelae of oxidative damage, retinal pigment epithelium (RPE) cell dysfunction with accumulation of lipofuscin and impairment of lysosomal functions, deposition of subsequently incompletely degraded material at the basal RPE cell side and alterations in Bruch's membrane extracellular matrix, immunologic responses to extracellular material (drusen) with subsequent growth of drusen, induction of choroidal neovascularization as a result of imbalance between anti-angiogenetic and proangiogenetic factors as well as cell death (geographic atrophy) without prior neovascular events. CONCLUSIONS: Understanding is expanding regarding the sequence of events that lead to early and late lesions in AMD. Therapeutic approaches that focus on the molecular mechanisms are more likely to succeed than currently available treatment options as exemplified by the management of choroidal neovascularisations.

Bindewald A, Stuhrmann O, Roth F, Schmitz-Valckenberg S, Helb HM, Wegener A, Eter N, Holz FG. · Department of Ophthalmology, University of Bonn, Ernst-Abbe-Strasse 2, D-53127 Bonn, Germany. · Br J Ophthalmol. · Pubmed #16299141 links to  free full text

Abstract: BACKGROUND: With the advent of digital confocal scanning laser ophthalmoscopy it is possible to detect low levels of fluorescence. Here we used a novel confocal scanning laser ophthalmoscope (cSLO) to determine lower limits of dye required for fluorescein (FL) and indocyanine green (ICG) angiography. METHODS: A cSLO (Heidelberg retina angiograph 2, Heidelberg Engineering, Dossenheim, Germany) with an optically pumped solid state laser (488 nm) for FL and a diode laser (790 nm) for ICG angiography (FL/ICG-A) was used. 62 FL-As were performed in 53 patients and 45 ICG-As were performed in 39 patients with neovascular age related macular degeneration. The volume and overall dye content of bolus injections was gradually tapered (FL: 500 mg, 250 mg, 200 mg, 166 mg, 100 mg; ICG: 25 mg, 20 mg, 15 mg, 10 mg, 5 mg, 2.5 mg), while dye concentrations were kept constant at 100 mg/ml for FL and at 5 mg/ml for ICG. Images were obtained 1, 5, 15, and 30 minutes after dye injection. Image quality was evaluated by two independent readers using standardised criteria. RESULTS: For amounts down to 166 mg for FL and to 5 mg for ICG, sufficient image quality was achieved during all phases following injection. Only late phase images showed less contrast compared to typically used dye amounts, which was irrelevant for interpretation and clinical management. CONCLUSIONS: With the increased sensitivity of this novel cSLO system, amounts of injected dye during FL-A can be reduced to one third for FL and to one fifth for ICG without relevant loss of image quality or information compared to conventionally used dye levels. These amounts can be used for routine angiography and allow relevant savings for units performing FL-A.

Bindewald A, Jorzik JJ, Roth F, Holz FG. · Augenklinik und Poliklinik, Universität, Bonn. · Ophthalmologe. · Pubmed #15490188 No free full text.

Abstract: BACKGROUND: Fundus autofluorescence (FAF) originates from age- and disease-dependent accumulation of lipofuscin in the lysosomal compartment of the retinal pigment epithelium (RPE). FAF imaging is a noninvasive method to detect intrinsic RPE fluorescence in vivo. We describe features of a novel confocal scanning laser ophthalmoscope (cSLO) for FAF imaging and compare images to the previous cSLO system.METHODS: FAF images were obtained with a cSLO using an optically pumped solid state laser (OPSL) instead of an argon laser for generation of excitation light at 488 nm. For detection of emitted FAF signals >500 nm a barrier filter was used.RESULTS: The novel cSLO allows FAF imaging with a resolution of up to 5 microm/pixel to delineate normal and pathological features in various retinal pathologies including early-stage and advanced atrophic or neovascular age-related macular degeneration, macular edema, and retinal dystrophies. Further technical improvements include an internal fixation target and an enlarged optical focus adaption range.CONCLUSIONS: Improved image quality using the novel cSLO for FAF imaging is of clinical relevance for diagnosis and precise phenotyping of retinal diseases. This method may also be useful to monitor therapeutic effects targeting RPE lipofuscin accumulation as a common pathogenetic pathway in various degenerative and hereditary retinal diseases.

Bindewald A, Roth F, Van Meurs J, Holz FG. · Universitäts-Augenklinik, Bonn. · Ophthalmologe. · Pubmed #15316735 No free full text.

Abstract: Neovascular age-related macular degeneration (AMD) has become the leading cause for severe visual loss in all industrialized nations. Surgical excision of choroidal neovascularizations (CNV) is technically feasible but invariably associated with inadvertent removal of corresponding retinal pigment epithelium (RPE) and subsequent atrophy of the choriocapillaris, with the latter two layers being a prerequisite for normal photoreceptor function. To cover the RPE defect both heterologous and homologous RPE cell suspensions have been injected into the subretinal space. The lack of functional improvement has been attributed to various factors including RPE cell dedifferentiation, failure of adherence to Bruch's membrane as well as development of a regular RPE cell monolayer. Therefore, techniques for translocating intact autologous RPE cell sheets have been sought and preservation of foveal neurosensory functions has recently been successfully demonstrated. Besides translocation of a full-thickness RPE/Bruch's membrane/choroid patch outside the macular area, superfluous choroidal tissue may be ablated intraocularly using an excimer laser prior to translocation. Besides recent pharmacological approaches including anti-VEGF agents, these surgical developments open new perspectives for patients with neovascular AMD.