PURPOSE To validate a scale for grading vitreous haze in uveitis using digitized photographs and standardized scoring. DESIGN Evaluation of clinical research methodology. METHODS Calibrated Bangerter diffusion filters inducing incremental decrements of spatial contrast were placed in front of the camera lens while photographing a normal eye to simulate vitreous haze. The photographs were digitized and an ordinal scale was created from 0 (none) to 8 (highest level of opacification at which fundus details could be seen). The scale steps correspond approximately to decimal Snellen visual acuities of 1.0, 0.8, 0.4, 0.2, 0.1, 0.04, 0.02, 0.01, and 0.002, with approximately 0.3 log step between each step. For validation, digitized fundus photographs of uveitis patients were displayed on a computer monitor for comparison with the standard photos. Three observers graded the test set twice under standard conditions. Interobserver and intraobserver variability and κ values for agreement greater than chance were calculated. RESULTS Variance component analysis determined that 87.7% of the variance in grades was attributable to the test item rather than to grader or session. The intraclass correlation between graders and grading sessions varied from 0.84 to 0.91. Simple agreement within 1 grade between graders and sessions occurred in 90 ± 5.5% of gradings. κ values averaged 0.91, which is considered near perfect. CONCLUSIONS A 9-step photographic scale was designed to standardize the grading of vitreous haze in uveitis patients using fundus photographs. The scale is potentially adaptable to clinical trials in uveitis.

Purpose-To investigate the relationship between drusen extent and foveolar choroidal blood flow in non-exudative AMD.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 non-exudative AMD. Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChB Vel ), volume (ChB Vol ), and flow (ChB Flow ) 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 mm 2 increase in total drusen area, ChB Vol decreased by 0.0061 arbitrary units (AU; p=0.03) and ChB Flow decreased by 0.23 AU (p=0.049). Average druse area was also significantly inversely related to ChB Vol and ChB Flow . For every 0.01 mm 2 increase in average druse area, the ChB Vol decreased by 0.0149 AU (p=0.001) and the ChB Flow decreased by 0.4951 AU (p=0.003). Adjustment for age weakened the significance, though 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 inter-grader agreement.Conclusion-In patients with non-exudative AMD, 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.