Macular Degeneration: Wang F

Zhou Q, Friedman DS, Lu H, Duan X, Liang Y, Yang X, Wang F, Wang N. · Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital University of Medical Sciences, China. · Ophthalmic Epidemiol. · Pubmed #18161614 No free full text.

Abstract: While many papers have been published regarding age-related eye diseases in Mainland China in the past two decades, the variable quality of those reports limit the conclusions that can be drawn. Many of these studies assessed blindness and low vision rates, and these estimates are likely accurate. However, due to lack of standardization of techniques for assessing cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy, estimates of the burden of these diseases on the population are less reliable. Owing to the rapid economic development of China in the last decade, resources to address eyecare problems are more likely to be available. Therefore, an accurate assessment of the burden of various eye diseases is needed in order to improve blindness prevention planning and program development.

Lujan BJ, Rosenfeld PJ, Gregori G, Wang F, Knighton RW, Feuer WJ, Puliafito CA. · Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA. · Ophthalmic Surg Lasers Imaging. · Pubmed #19320296 No free full text.

Abstract: BACKGROUND AND OBJECTIVE: To compare images of geographic atrophy (GA) obtained using spectral domain optical coherence tomography (SD-OCT) with images obtained using fundus autofluorescence (FAF). PATIENTS AND METHODS: Five eyes from patients with dry AMD were imaged using SD-OCT and FAF, and the size and shape of the GA were compared. RESULTS: GA appears bright on SD-OCT compared with the surrounding areas with an intact retinal pigment epithelium because of increased reflectivity from the underlying choroid. SD-OCT and FAF both identified GA reproducibly, and measurement of the area of GA is comparable between the two methods with a mean difference of 2.7% of the total area. CONCLUSION: SD-OCT can identify and quantitate areas of GA. The size and shape of these areas correlate well to the areas of GA seen on autofluorescence images; however, SD-OCT imaging also provides important cross-sectional anatomic information.

Lujan BJ, Wang F, Gregori G, Rosenfeld PJ, Knighton RW, Puliafito CA, Danis RP, Hubbard LD, Chang RT, Budenz DL, Seider MI, Knight O. · Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA. · Ophthalmic Surg Lasers Imaging. · Pubmed #18777875 No free full text.

Abstract: BACKGROUND AND OBJECTIVE: Measurements performed on fundus images using current software are not accurate. Accurate measurements can be obtained only by calibrating a fundus camera using measurements between fixed retinal landmarks, such as the dimensions of the optic nerve, or by relying on a calibrated model eye provided by a reading center. However, calibrated spectral domain OCT (SD-OCT) could offer a convenient alternative method for the calibration of any fundus image. PATIENTS AND METHODS: The ability to measure exact distances on SD-OCT fundus images was tested by measuring the distance between the center of the fovea and the optic nerve. Calibrated SD-OCT scans measuring 6 X 6 X 2 mm centered on the fovea and the optic nerve were analyzed in 50 healthy right eyes. The foveal center was identified using cross-sectional SD-OCT images, and the center of the optic nerve was identified manually. The SD-OCT scans were registered to each other, and the distances between the center of the optic nerve and fovea were calculated. The overlay of these SD-OCT fundus images on photographic fundus images was performed. RESULTS: Any image of the fundus could be calibrated by overlaying the SD-OCT fundus image, and the measurements were consistent with previously defined calibration methods. The mean distance between the center of the fovea and the center of the optic nerve was 4.32 +/-0.32 mm. The line from the center of the optic nerve to the foveal center had a mean declination of 7.67 +/- 3.88 degrees. Mean horizontal displacement and vertical displacement were 4.27 +/- 0.29 mm and 0.58 +/- 0.29 mm, respectively. CONCLUSIONS: The overlay of the SD-OCT fundus image provides a convenient method for calibrating any image of the fundus. This approach should provide a uniform standard when comparing images from different devices and from different reading centers.

Wang F, Wang H, Zhuang J, Xu Q. · Department of Ophthalmology, Shanghai Shibei Hospital, Shanghai 200435, China. · Yan Ke Xue Bao. · Pubmed #12579676 No free full text.

Abstract: PURPOSE: To explore the image features of exudative age-related macular degeneration (AMD) with B-scan. METHODS: Using NIDEK US-3300 model B-scan to observe 31 patients (54 eyes) with AMD. RESULTS: The membranous arc echo was found at the posterior polar and there was a shuttle absence of echo between the echo band and the wall of eyeball in the period of retinal pigment epithelium detachment. During the exudation and hemorrhage absorbed not comletely, mixed echo was seen. A small parenchyma body with protrusion was seen with stronger echo in the late phase when the exudation and hemorrhage were replaced by the scar tissues, it was like a convex lens or a triangle and the top pointed to the globe behind, but it was flat towards the vitreous. CONCLUSION: The B-scan examination is valuable in diagnosis, treatment and follow-up for exudative AMD.

Wang F, Rendahl KG, Manning WC, Quiroz D, Coyne M, Miller SS. · School of Optometry and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA. · Invest Ophthalmol Vis Sci. · Pubmed #12556414 links to  free full text

Abstract: PURPOSE: To develop a small-animal model of choroidal neovascularization (CNV) by injecting adeno-associated virus (AAV)-VEGF into the subretinal space (SRS) of rats. METHODS: An adeno-associated viral vector encoding human VEGF(165) was injected into the subretinal space (SRS) of Sprague-Dawley or Long Evans rats. Expression of VEGF was identified by RT-PCR and immunohistochemistry. Physiological and pathologic changes in the retina and choroid were evaluated by electroretinography, fluorescein angiography, light microscopy, and three-dimensional reconstruction of serial sections. RESULTS: Green fluorescent protein (GFP) and VEGF were expressed for at least 20 months in the retina and retinal pigment epithelium (RPE). Histologic sections showed extensive subretinal neovascularization, degenerating photoreceptors, and proliferating RPE at 5 weeks to 20 months after injection of AAV-VEGF. At 2 to 12 months after injection, leaking blood vessels were detected by fluorescein angiography. Electroretinogram a- and b-wave amplitudes were significantly decreased during this time. Three-dimensional reconstruction of serial sections demonstrated that choroidal blood vessels penetrated Bruch's membrane, one of them splitting into three branches in the SRS. In the current model, CNV was produced in 95% of the animals tested (19/20). It persisted for more than 20 months, a necessary requirement for modeling the development of CNV in age-related macular degeneration (AMD). CONCLUSIONS: In this study, a highly reproducible animal model of long-lasting CNV was developed. This model is being used to test antiangiogenic molecules to reduce or inhibit CNV and could be extended to primates.