Modulation transfer function of implantable phakic intraocular contact lens (IPCL) for myopia and presbyopia.

Purpose: This study aimed to assess the optical quality of myopic and presbyopic IPCLs with different additional powers, and to investigate the effects of pupil size on the optical quality of these IPCLs using an in-vitro modulation transfer function (MTF) measurement system. Methods: Linear scatter functions (LSFs) were recorded using the OPAL Vector system and an eye phantom consisting of wet cells filled with a balanced salt solution. A myopic IPCL or a presbyopic IPCL was placed in the posterior chamber of this model. The MTF was calculated from the LSF using the fast Fourier transform techniques. The effective apertures were set at 2.0 to 5.0 mm in 1.0 mm steps. Results: The in-focus MTF values of the myopic IPCL and presbyopic IPCL with additional powers of + 2.0 and + 4.0 diopters at 100 cycles/mm for an effective aperture of 3.0 mm were 43%, 27%, and 24%, respectively. The in-focus MTF value of both myopic and presbyopic IPCLs was the highest when the effective aperture was set at 3.0 mm, and it gradually worsened when the effective aperture became larger than 3.0 mm at 20, 60, and 100 cycles/mm. Conclusions: Both myopic and presbyopic IPCLs provided excellent MTF values, but the additional power profile can deteriorate optical performance in presbyopic IPCL-implanted eyes, even with a low additional power. Pupil size can influence visual quality in IPCL-implanted eyes for both myopia and presbyopia. Key Messages: What is known: • Implantable phakic contact lens (IPCL) has been reported to be effective for the treatment of both myopia and presbyopia, with a noticeable advantage in reducing the patients' cost burden. • The optical properties of IPCL have not yet been thoroughly investigated, neither for myopic IPCLs nor for presbyopic IPCLs. What is new: • The MTF of presbyopic IPCL was slightly lower than that of myopic IPCL even with a low additional power. • The MTF values of both myopic and presbyopic IPCLs were the highest for a 3.0 mm-pupil size, with gradually worsened for a larger pupil size. [ABSTRACT FROM AUTHOR]