One previous study by Nesterov et al.
8 reported the presence of a significantly shorter scleral spur in POAG eyes compared to normal eyes; however, we found that the method of Nesterov and Batmanov
17 actually measured the height of scleral spur, not the length, as their values for the scleral spur length in normal eyes were similar to the values of the scleral spur height reported by Hamanaka et al.
6 In our attempt to replicate the values of Nesterov and Batmanov
17 for their interpretation of the scleral spur length, sometimes called the diameter by Nesterov and Batmanov,
17 we used the method of Hamanaka
6 to measure the scleral spur height in normal eyes (
Fig. 1B), and we obtained a value (0.081 ± 0.003 mm) that was similar to the Nesterov and Batmanov
17 value of scleral spur length in normal eyes (0.085 ± 0.003 mm, 1-sample
t-test,
P = 0.276), but significantly different from the values of Hamanaka
6 of the scleral spur height in normal eyes (0.093 ± 0.022 mm, 1-sample
t-test,
P = 0.039). The difference between the Hamanaka
6 value and ours could be a result of differences in sample patient population. These values are very different from the value of scleral spur length obtained by our method and that of Moses and Arnzens.
20 In POAG eyes, although both of the studies by Nesterov et al.
8,17 and our interpretation of the method of Nesterov and Batmanov
17 obtained significantly smaller values, there was a significant difference between their and our observations (1-sample
t-test,
P < 0.0001). Again, this difference could be a result of differences in patient population or our relatively small sample size compared to the report of Nesterov and Batmanov.
17 Nevertheless, the method of Nesterov and Batmanov
17 actually measures the height of the scleral spur (as described by Hamanaka,
6 from its tip to the level of the posterior end of SC). Thus, their method (
Fig. 1B) does not provide as accurate a measure of the actual scleral spur length as our method developed in this study. Using the method devised in this study, which measures the length of the scleral spur more accurately and takes into account its curvature, we were able to come to the same conclusion as Nesterov and Batmanov,
17 that POAG eyes have significantly shorter scleral spurs compared to normal eyes (
P < 0.0001,
Fig. 2A).