Response to O’Brart: ‘Is accelerated cross-linking the way forward? Yes or No’

Sir,

We welcome the comments of O’Brart¹ regarding our controversy articles ‘Is Accelerated cross-linking the way forward? Yes or No’.^{2, 3}

We agree that the presence of a demarcation line cannot be taken in isolation as a measure of treated versus untreated cornea; however, there is substantial microscopic, biomechanical and clinical evidence^{4, 5, 6} to support the hypothesis that this line described by Seiler and Hafezi⁷ does indeed demarcate between cross-linked and uncross-linked cornea. Further work is clearly warranted.

Although Reinstein et al⁸ have published elegant work demonstrating the epithelial changes in early keratoconus, this work is yet to be widely reproduced. For the large majority of workers in the field, changes in posterior corneal elevation detected using slit scanning or Scheimpflug imaging remains the mainstay of early diagnosis and is still considered to be the principle area of initial morphological change.^{9, 10, 11, 12}