In group A , the speed of sound of the treated corneas was 1677.38 10.70 ms ( -1 ) anteriorly and 1603.90 9.82 ms ( -1 ) posteriorly , while it was 1595.23 9.66 ms ( -1 ) anteriorly and 1577.13 8.16 ms ( -1 ) posteriorly in the controls .