Author’s reply

Abstract

Drs. Gimbel, van Westenbrugge, and Penno make important points with regard to the clinical implications of our paper. As we did stress, our study was theoretical. Not withstanding this design, however, we did find a correlation in refractive outcome between the two eyes of an individual patient. This suggests that the first eye result may be applied to improve the outcome of the second eye in some patients. Such a correlation has been supported by other investigators (Nguyen LH, et al. Invest Ophthalmol Vis Sci 2000[Suppl]:41, S687). This finding implies the need for clinical studies specifically directed at this issue if we want to definitively answer the question, but does not address the clinical significance of such a between-eye correlation. Other factors, including general safety of bilateral procedures found in current clinical studies, anisometropia between surgery, and patient dissatisfaction with needing two operative sessions, may mitigate any advantage gained.Analysis in those clinical studies to date that show no difference in refractive outcomes between simultaneous and sequential LASIK, although well designed and executed, are population based and are not specifically designed to look at individual patients in whom this between-eye correlation may be clinically important. Rather, clinical trials specifically addressing the potential difference between simultaneous and sequential treatments with regard to the predictive ability of the first eye on second eye refractive outcome are necessary to uncover or dispel any actual clinical significance of our findings. In the absence of such further study, careful clinical judgment should be used in the decision to perform simultaneous or sequential surgery on an individual patient. Drs. Gimbel, van Westenbrugge, and Penno make important points with regard to the clinical implications of our paper. As we did stress, our study was theoretical. Not withstanding this design, however, we did find a correlation in refractive outcome between the two eyes of an individual patient. This suggests that the first eye result may be applied to improve the outcome of the second eye in some patients. Such a correlation has been supported by other investigators (Nguyen LH, et al. Invest Ophthalmol Vis Sci 2000[Suppl]:41, S687). This finding implies the need for clinical studies specifically directed at this issue if we want to definitively answer the question, but does not address the clinical significance of such a between-eye correlation. Other factors, including general safety of bilateral procedures found in current clinical studies, anisometropia between surgery, and patient dissatisfaction with needing two operative sessions, may mitigate any advantage gained. Analysis in those clinical studies to date that show no difference in refractive outcomes between simultaneous and sequential LASIK, although well designed and executed, are population based and are not specifically designed to look at individual patients in whom this between-eye correlation may be clinically important. Rather, clinical trials specifically addressing the potential difference between simultaneous and sequential treatments with regard to the predictive ability of the first eye on second eye refractive outcome are necessary to uncover or dispel any actual clinical significance of our findings. In the absence of such further study, careful clinical judgment should be used in the decision to perform simultaneous or sequential surgery on an individual patient.