Macular Degeneration: Enzmann V

Wolf-Schnurrbusch UE, Stuck AK, Hess R, Wolf S, Enzmann V. · Department of Ophthalmology, Inselspital, University of Bern, Bern, Switzerland. · Retina. · Pubmed #19584655 No free full text.

Abstract: PURPOSE: To evaluate whether complement Factor P (properdin) was present in surgically removed choroidal neovascular membranes of patients with age-related macular degeneration (AMD) and to investigate whether associated pre- and postoperative clinical characteristics can be correlated. METHODS: The study population consisted of 26 AMD patients (26 eyes) with the exclusion criterion of prior treatment of the choroidal neovascular membranes. Factor P was detected immunocytochemically on paraffin sections (7 microm) by a polyclonal rabbit antihuman antibody. RESULTS: Eleven of 22 assessable membranes showed a positive reaction for Factor P. The average percentage of Factor P-positive cells per membrane ranged from 0.65% to 4.09%. The duration of visual loss was significantly longer (8.6 +/- 2.7 vs. 3.9 +/- 0.8 months), and the size of postoperative measured area of atrophic retinal pigment epithelium was larger (27.6 +/- 7.6 vs. 15.0 +/- 6.9 mm2) in patients with Factor P-positive membranes compared with Factor P-negative ones. CONCLUSION: Factor P was expressed in 50% of choroidal neovascular membranes of patients with AMD. The group with Factor P-positive membranes differed significantly from the Factor P-negative group in key clinical outcomes. Additional studies need to investigate the role of Factor P in the development of AMD for potential therapeutic intervention.

Wolf-Schnurrbusch UE, Enzmann V, Brinkmann CK, Wolf S. · Klinik und Poliklinik für Augenheilkunde, Inselspital, University of Bern, Bern, Switzerland. · Invest Ophthalmol Vis Sci. · Pubmed #18378583 links to  free full text

Abstract: PURPOSE: To investigate the appearance of geographic atrophy in high-resolution optical coherence tomography (OCT) images, the fundus autofluorescence (FAF) pattern, and infrared images simultaneously recorded with a novel combined OCT-scanning laser ophthalmology (SLO) system. METHODS: Patients aged over 50 years with geographic atrophy secondary to dry age-related macular degeneration (ARMD) were assessed in a prospective cross-sectional study by means of simultaneous spectral OCT-SLO (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany). The integrity of the retinal layers was analyzed in the apparently normal areas, the junctional zone between the normal retina and the geographic atrophy, and the atrophic area. The presence and integrity of the external limiting membrane, the photoreceptor inner segments, the outer segments, and the retinal pigment epithelium were assessed. RESULTS: Fifty-two eyes of 52 patients (28 women, 24 men) aged 51 to 92 years were examined. Retinal layer alterations were documented, not only in atrophic zones, but also in junctional zones surrounding the geographic atrophy. Disintegration of the retinal layers began in the RPE and adjacent retinal layers, such as the photoreceptor inner and outer segments and external limiting membrane. CONCLUSIONS: Novel imaging modalities will provide further valuable insight into ARMD pathogenesis. The key to understanding the morphologic change lies in in vivo depiction of retinal layers by spectral OCT technology in combination with other imaging modalities such as FAF.

Atmaca-Sonmez P, Li Y, Yamauchi Y, Schanie CL, Ildstad ST, Kaplan HJ, Enzmann V. · Department of Ophthalmology & Visual Sciences, University of Louisville, 301 E. Muhammad Ali Blvd., Louisville, KY 40202, USA. · Exp Eye Res. · Pubmed #16949576 No free full text.

Abstract: Stem cell regeneration of damaged tissue has recently been reported in many different organs. Since the loss of retinal pigment epithelium (RPE) in the eye is associated with a major cause of visual loss - specifically, age-related macular degeneration - we investigated whether hematopoietic stem cells (HSC) given systemically can home to the damaged subretinal space and express markers of RPE lineage. Green fluorescent protein (GFP) cells of bone marrow origin were used in a sodium iodate (NaIO(3)) model of RPE damage in the mouse. The optimal time for adoptive transfer of bone marrow-derived stem cells relative to the time of injury and the optimal cell type [whole bone marrow, mobilized peripheral blood, HSC, facilitating cells (FC)] were determined by counting the number of GFP(+) cells in whole eye flat mounts. Immunocytochemistry was performed to identify the bone marrow origin of the cells in the RPE using antibodies for CD45, Sca-1, and c-kit, as well as the expression of the RPE-specific marker, RPE-65. The time at which bone marrow-derived cells were adoptively transferred relative to the time of NaIO(3) injection did not significantly influence the number of cells that homed to the subretinal space. At both one and two weeks after intravenous (i.v.) injection, GFP(+) cells of bone marrow origin were observed in the damaged subretinal space, at sites of RPE loss, but not in the normal subretinal space. The combined transplantation of HSC+FC cells appeared to favor the survival of the homed stem cells at two weeks, and RPE-65 was expressed by adoptively transferred HSC by four weeks. We have shown that systemically injected HSC homed to the subretinal space in the presence of RPE damage and that FC promoted survival of these cells. Furthermore, the RPE-specific marker RPE-65 was expressed on adoptively transferred HSC in the denuded areas.