Final answer:
For the success in fitting Ortho-K, corneal thickness and corneal topography are essential as they allow for fine control over reshaping the cornea to correct vision in the majority of patients, while initial eye color is not relevant.
Step-by-step explanation:
Essential for success in fitting Ortho-K (Orthokeratology), which is a method of corneal reshaping to reduce refractive errors like myopia, is the determination of factors that influence the efficacy of the treatment. One such factor is the corneal thickness. This thickness is important because it implies that the shaping of the cornea can be very finely controlled, enabling the correction of normal distant vision in more than 90% of patients. Another crucial factor is corneal topography, which provides detailed information about the curvature of the cornea, essential for creating the Ortho-K lenses that are tailored to the individual's eye structure.
Initial eye color is not relevant to the success of Ortho-K treatments. Initial refractive error does make a difference, as Ortho-K is best suited for certain ranges of myopia, hyperopia, and astigmatism. However, factors such as corneal thickness and corneal topography take precedence in terms of fitting efficacy because these physical corneal characteristics directly affect how the lenses can shape the cornea, thus affecting the final visual outcome.