New bi-sign aspheric IOL and its application.

Area of Science:

• Ophthalmology
• Optical Engineering
• Vision Science

Background:

• Intraocular lenses (IOLs) are crucial for vision correction after cataract surgery.
• Spherical aberrations in the eye can degrade image quality.
• Aspheric IOL designs aim to correct these aberrations, but performance can vary.

Purpose of the Study:

• To introduce a novel bi-aspheric intraocular lens (IOL).
• To theoretically compare the bi-aspheric IOL with spherical and mono-aspheric IOLs.
• To evaluate retinal image quality in mesopic conditions and intermediate vision in photopic conditions.

Main Methods:

• Ray-tracing simulations were performed in pseudophakic eye models.
• Retinal image quality was assessed using modulation transfer function (MTF).
• Analyses considered various corneal asphericities, lens misalignments, and pupil diameters (3mm and 5mm).

Main Results:

• The bi-aspheric IOL demonstrated equal or superior retinal image quality compared to mono-aspheric and spherical IOLs across most conditions.
• Performance was maintained across a range of anterior cornea asphericities and lens misalignments.
• The bi-aspheric IOL showed enhanced intermediate image capability compared to the spherical IOL.

Conclusions:

• The bi-aspheric IOL design effectively balances internal and corneal aberrations.
• This lens design reduces the variability of retinal image quality.
• Positive longitudinal spherical aberration in the bi-aspheric IOL improves intermediate vision.