Accelerated reperfusion of poorly perfused retinal areas in central retinal artery occlusion and branch retinal artery occlusion after a short treatment with enhanced external counterpulsation. Treatment of vascular retinal disease with pentoxifylline: a controlled, randomized trial.
To date, no satisfactory therapy has become available for patients with acute central retinal artery occlusion (CRAO) or branch retinal artery occlusion (BRAO). Enhanced external counterpulsation (EECP) is a new noninvasive procedure that increases perfusion of inner organs. In the current study, the authors measured the impact of EECP on reperfusion in ischemic retinal tissue.
                In a prospective, randomized study, 20 patients with CRAO or BRAO were included. Ten patients were given hemodilution therapy and 2 hours of EECP, and 10 patients were given regular hemodilution therapy only. Quantification of changes in retinal perfusion was carried out by means of scanning laser Doppler flowmetry (in arbitrary units).
                Enhanced external counterpulsation caused no observable adverse events. A significant increase in perfusion occurred immediately after EECP in the ischemic retinal areas (57 +/- 19 arbitrary units versus 99 +/- 14 arbitrary units). In contrast, no change was measured in the group not treated with EECP (83 +/- 19 arbitrary units versus 89 +/- 44 arbitrary units). Forty-eight hours later, a significant increase in perfusion could be shown in the ischemic retina of both groups, and no significant difference of perfusion was found between the two groups any longer.
                The current study suggests that EECP could be a clinically useful and safe procedure in patients with CRAO or BRAO to accelerate recovery of perfusion in ischemic retinal areas. The aim of this study was to evaluate the effect of PXF (1800 mg daily) in patients with sudden loss of vision (SLV) in a 4-week trial, evaluating clinical outcome and retinal flow parameters. Inclusion criteria were SLV associated with thrombosis of the retinal artery; decrease in retinal blood flow (PSF: peak-systolic flow; EDF: end-diastolic flow velocity) and asymmetry between the two retinal arteries (>40%) documented by duplex scanning. All 10 included patients completed the study. The groups were comparable. No side effects were reported. A significant improvement in flow velocity (p<0.05) and a decrease in analogue score in both groups were observed. PSF increase was 550% in the PXF group vs 288% in the placebo group (262% difference). EDF increase was 400% in the PXF group vs 200% in the placebo group (200% difference). There was a significant difference in the analogue score decrease (33.3% difference larger in the PXF group; p<0.05). In conclusion, PXF treatment improved retinal flow after retinal artery occlusion better than placebo and should be considered as an important option in this condition.
The included studies in this review were small and from single centres. Neither study was completely clear about it's method of treatment allocation. One study described the use of pentoxifylline tablets (three 600 mg tablets daily) and the other the use of enhanced external counterpulsation (EECP) combined with haemodilution. Both studies indicated improved retinal perfusion in the non-control group but neither showed an improvement in vision. Large, well-designed RCTs are still required to establish the most effective treatment for acute CRAO. These studies should be looking at factors important to the patient i.e. improved vision with acceptable risk/side-effects.