Final answer:
In Ortho-K, evaluating sagittal depth examines the fitting relationship between an ortho-K lens and the cornea, ensuring effective vision correction and comfort.
Step-by-step explanation:
Evaluating sagittal depth in Ortho-K (Orthokeratology) is primarily associated with B) Evaluating the fitting relationship between lens and cornea. This evaluation does not directly measure the central corneal thickness, which is often done using pachymetry. Instead, it focuses on how well an ortho-K lens fits on the cornea based on the corneal curvature and sagittal depth, thereby ensuring effective and comfortable vision correction. It does not assess the curvature of the cornea (which can be done using a keratometer, as seen in Example 25.11), nor does it determine tear film quality. Ortho-K lenses are specially designed contact lenses that temporarily reshape the cornea to correct refractive errors such as myopia.