Ultra widefield fundus imaging for diabetic retinopathy.

For decades, the standard method for screening and grading severity of diabetic retinal disease has relied upon a montage of photographs using normal angle fundus cameras. With the development of ultrawide field (UWF) fundus imaging, more of the retina can be imaged with fewer pictures, less dependence on photographer skill, and, often, greater ease on the patient. Recent studies have shown comparability between traditional and UWF imaging for standard grading of diabetic retinopathy. Moreover, UWF images can detect peripheral pathology not typically seen in standard photographs, which may enlighten our understanding of disease severity and suggest new indications for treatment.

The association between drusen extent and foveolar choroidal blood flow in age-related macular degeneration.

PURPOSE: To investigate the relationship between drusen extent and foveolar choroidal blood flow in nonexudative age-related macular degeneration. METHODS: Total drusen area, average druse area, and total drusen number were determined using a computer program developed to quantify the extent of manually outlined drusen from fundus photographs of 157 patients (239 eyes) with nonexudative age-related macular degeneration. Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChBVel), volume (ChB Vol), and flow (ChBF low) in the center of the fovea. RESULTS: We found a significant inverse relationship between total drusen area and ChB Vol or ChB Flow. For every 1-mm2 increase in total drusen area, ChB Vol decreased by 0.0061 arbitrary units (P = 0.03) and ChBF low decreased by 0.23 arbitrary units (P = 0.049). Average druse area was also significantly inversely related to ChB Vol and ChBF low. For every 0.01-mm2 increase in average druse area, the ChB Vol decreased by 0.0149 arbitrary units (P = 0.001) and the ChB Flow decreased by 0.4951 arbitrary units (P = 0.003). Adjustment for age weakened the significance, although it remained strong for average druse area versus ChB Flow (P = 0.017) and ChB Vol (P = 0.004). The computer-aided quantification of drusen used in this study showed high intra- and intergrader agreement. CONCLUSION: In patients with nonexudative age-related macular degeneration, there is an association between increased drusen extent and decreased ChB Vol and ChB Flow. This suggests the presence of ischemia and possibly the reason why patients with high-risk drusen are prone to advanced disease.

Enhancement of DNA tumor vaccine efficacy by gene gun-mediated codelivery of threshold amounts of plasmid-encoded helper antigen.

Nucleic acid-based vaccines are effective in infectious disease models but have yielded disappointing results in tumor models when tumor-associated self-antigens are used. Incorporation of helper epitopes from foreign antigens into tumor vaccines might enhance the immunogenicity of DNA vaccines without increasing toxicity. However, generation of fusion constructs encoding both tumor and helper antigens may be difficult, and resulting proteins have unpredictable physical and immunologic properties. Furthermore, simultaneous production of equal amounts of highly immunogenic helper and weakly immunogenic tumor antigens in situ could favor development of responses against the helper antigen rather than the antigen of interest. We assessed the ability of 2 helper antigens (beta-galactosidase or fragment C of tetanus toxin) encoded by one plasmid to augment responses to a self-antigen (lymphoma-associated T-cell receptor) encoded by a separate plasmid after codelivery into skin by gene gun. This approach allowed adjustment of the relative ratios of helper and tumor antigen plasmids to optimize helper effects. Incorporation of threshold (minimally immunogenic) amounts of helper antigen plasmid into a DNA vaccine regimen dramatically increased T cell-dependent protective immunity initiated by plasmid-encoded tumor-associated T-cell receptor antigen. This simple strategy can easily be incorporated into future vaccine trials in experimental animals and possibly in humans.