Among a series of patients with age-related macular degeneration (ARMD), a few individuals could be identified showing larger amplitudes of pattern reversal visual evoked potentials (prVEP) after stimulation of a central 3° field compared to stimulation of a 13° field although in the majority of ARMD patients and in normals, VEP amplitudes increased with increasing field size. An analysis of prVEPs recorded after stimulation of different macular zones showed that the 3° central area and the perifoveal zone contributed differently to the 13° response or macular response. Perifoveal activity in this subgroup of ARMD patients seemed to mask the foveal contribution to the macular prVEP. The cortical magnification factor in ARMD may be higher than in normal controls. Small-field stimulation techniques are therefore also recommended in patients with central retinal pathology.

Repetitive treatment with membrane differential filtration is able to improve visual function in patients with diabetic retinopathy. The present study suggests that repetitive membrane differential filtration treatment could be a useful adjunct along with laser treatment to influence the clinical course of diabetic maculopathy.

196 plateletapheresis procedures using the cell separator Haemonetics V 50 were performed applying 8 cycles under varying conditions. The anticoagulant ACD-A was used in a whole-blood to anticoagulant ratio of 8:1. The flow rate was selected for a range of 40-70 ml/min and the centrifuge speed was established at 4,800 and 4,400 rpm. The PWC factor was chosen between 0 and 4. 162 procedures could be statistically evaluated. 34 aphereses were accompanied with technical complications. The mean yield was (4.3 ± 1.05) × 10¹¹ platelets, and the average of extraction efficiency (EE) was 53.9 ± 8.2 %. An analysis of variance confirmed that a higher flow rate decreased the EE (p < 0.002) and also the leukocyte counts (p < 0.0005). Increasing the PWC factor led to a higher EE; however, the leukocyte counts of the platelet concentrate were also increased (p < 0.0005). The g force has an essential effect. A high g force of the centrifuge permits to obtain a large quantity of platelets which is combined with a higher leukocyte contamination, Decreasing the centrifuge speed to 4,400 rpm by using PWC factors of 0 and 4 with different flow rates (50 and 60 ml/min) decreased the EE and the leukocyte counts in the product.