Comparison of pulsatile ocular blood flow in Indians and Europeans

To compare pulsatile ocular blood flow (POBF) in Europeans and Indians and provide reference values for a group of healthy Indians.

Measurement with the POBF Tonograph was performed on healthy Indian subjects in India (n=252). A further 80 subjects (40 of Indian descent and 40 Europeans) underwent measurements in Cambridge, England. The instrument used for measurement was the same for both the studies.

The mean POBF in the Indians in India was found to be 1176 microl/min. The mean POBF value in the Europeans was found to be 1033 microl/min and that for Indians in England was 1061 microl/min. The difference between the POBF within groups was significant (one-way ANOVA P<0.05) with the POBF of Indians in India being higher than Europeans and Indians in the UK. The difference between the Europeans and Indians in the UK did not reach statistical significance.

POBF values in Indians living in India were found to be considerably higher than the previously published normal value of 650 microl/min in European studies and other studies for other racial groups. The reason for this apparent difference may be instrument-related rather than genetic because such a large difference was not observed when a comparison was performed in the UK. In addition, the results for both groups in our comparative study were still considerably higher than reported in previous studies. The POBF of Indians in India is slightly higher than the POBF of people of Indian ethnic origin in England.