What crucial parameter must be considered when fitting a contact lens for an aphakic patient?

When fitting a contact lens for an aphakic patient, one of the most crucial parameters to consider is the presence of ultraviolet (UV) inhibitors in the lens. Aphakia, which refers to the absence of the eye's natural lens typically due to cataract surgery, greatly increases a patient's risk of UV-related eye damage because they no longer have the protective filtering qualities of the natural lens. Therefore, selecting a contact lens that includes a UV inhibitor helps shield the retina from harmful ultraviolet radiation, which can decrease the risk of conditions such as retinal damage or other UV-induced complications.

While other factors like contact lens material, contact lens solution, and edge thickness are important in the overall fitting and comfort of the lenses, they do not directly address the increased vulnerability to UV light that aphakic patients experience. This highlights the particular importance of UV protection in the choice of contact lenses for these individuals.