Tritan colour contrast sensitivity function in refractive multifocal intraocular lenses

Area of Science:

• Ophthalmology
• Vision Science
• Optometry

Background:

• Intraocular lenses (IOLs) are crucial for vision correction after cataract surgery.
• Multifocal IOLs offer improved near and distance vision but can affect visual quality.
• Tritan color contrast sensitivity (CCS) is important for visual function and can be affected by optical designs.

Purpose of the Study:

• To compare tritan color contrast sensitivity (CCS) in patients with refractive multifocal IOLs versus monofocal IOLs.
• To evaluate the impact of glare on tritan CCS for both types of IOLs.
• To assess the performance of multifocal IOLs in distance and near focus modes under varying light conditions.

Main Methods:

• Tritan CCS was measured using the Moorfields Vision System in eyes with multifocal (n=15) and monofocal (n=11) IOLs.
• Measurements were conducted under mesopic conditions at different spatial frequencies (0.5–22.8 cpd).
• Testing included conditions with and without glare, and for multifocal IOLs, both distance and near focus were assessed.

Main Results:

• Without glare, multifocal IOLs showed significantly worse tritan CCS at low spatial frequencies (0.5, 1.0 cpd) compared to monofocal IOLs.
• With glare, multifocal IOLs performed worse than monofocal IOLs at 0.5 and 1.0 cpd.
• Monofocal IOLs demonstrated superior performance across multiple spatial frequencies (0.5–6.0 cpd) under glare conditions.

Conclusions:

• Refractive multifocal IOLs significantly influence tritan color contrast sensitivity compared to monofocal IOLs.
• The presence of glare exacerbates the reduction in tritan CCS with multifocal IOLs.
• Monofocal IOLs provide better tritan CCS, particularly under challenging lighting conditions.