Purpose To evaluate the interobserver and intraobserver reliability of a commercially available, portable, ultrasonic pachymeter. Methods For the interobserver variability study, 42 healthy subjects underwent repeated ultrasonic pachymetry under topical anaesthesia performed by two observers. For the intraobserver study, another 30 further healthy subjects underwent repeated pachymetry by one of the observers. Agreement was analysed by means of Bland-Altman plots and by determination of the intraclass correlation coefficient. Results For the interobserver variability study, the mean measurement difference between observers was 0.7 lm (95% CI À0.8-2.2 lm) and the intraclass correlation coefficient was 0.9958 (95% CI 0.9922-0.9977). The Bland-Altman plot showed narrow limits of agreement with respect to central corneal thickness (CCT). For the intraobserver variability study, the mean difference between the repeated measurements was 0.9 lm (95% CI À3.1-1.3 lm). The intraclass correlation coefficient was 0.9934 (95% CI 0.9863-0.9969). A Bland-Altman plot again showed narrow limits of agreement with respect to CCT. The mean CCT for 72 subjects was 538 lm (95% CI 528-545 lm). Conclusions Measurements of CCT using the BVI Pocket Pachymeter were repeatable and had excellent interobserver reliability. Measurement variation amounted to less than 0.2% assuming a mean CCT of 538 lm.

Purpose:  To study the effect of ethnicity on pulsatile ocular blood flow (POBF). Methods:  Eighty subjects from the staff and student population at Anglia Polytechnic University were examined. Forty subjects (20 males, 20 females) were Asian (originating from the Indian subcontinent) and 40 (20 males, 20 females) were white people. The subjects underwent a complete ophthalmic examination including refraction, slitlamp examination and biomicroscopic fundoscopy. Subjects with ocular pathology were excluded from the study. Subjects underwent POBF measurement on a randomly selected eye with an Ocular Blood Flow Analyzer (Paradigm Medical Industries, Salt Lake City, UT, USA). The Analyzer probe was mounted on a slitlamp and all measurements were performed by an experienced observer (PG). Results:  The median age of the Asian subjects was 22 years (males 22 years; females 22 years) and of the white people was 24 years (males 26 years; females 23 years). The racial groups were comparable for age (Mann–Whitney U = 686.5, p = 0.27), refraction (Mann–Whitney U = 735.5, p = 0.4658) and IOP (Mann–Whitney U = 856, p = 0.5899). The mean POBF values in the Caucasian and Asian groups were 1033 µL min−1 (95% CI: 940–1125 µL min−1) and 1061 µL min−1 (95% CI: 958–1165 µL min−1), respectively. The difference in POBF between the ethnic groups did not reach statistical significance (Mann–Whitney U = 0.07, p = 0.7987). Females had a higher mean POBF than males (Mann–Whitney U = 1163; p = 0.0005) but there was no interaction with race (two‐way anovaF = 1.09; p = 0.2997). Conclusions:  There was no significant difference between the mean POBF values for subjects originating from the Indian subcontinent and Caucasian subjects. The previously reported gender difference in mean POBF was confirmed. We suggest that reported differences in POBF values in different races may arise from instrumental factors.