Implementation of the Frequency Scatter Index in Clinical Commercially Available Double-pass Systems

Area of Science:

• Ophthalmology
• Optical Engineering
• Biomedical Optics

Background:

• Intraocular scattering impacts visual quality.
• Previous methods used specialized double-pass instruments.
• A robust index, the frequency scatter index (FSI), was previously developed.

Purpose of the Study:

• To evaluate an adaptation of the FSI for clinical double-pass systems.
• To assess the FSI's utility in quantifying intraocular scattering in patients with nuclear cataracts.
• To determine the FSI's robustness against ocular aberrations.

Main Methods:

• Prospective observational study on 52 nuclear cataract patients and 11 controls.
• Used conventional double-pass systems to measure scattering.
• Calculated Spearman correlation between FSI and objective scatter index (OSI).
• Simultaneous measurements with double-pass and Hartmann-Shack sensor in controls.

Main Results:

• Strong correlation (ρ = 0.929, p < .0001) between FSI and OSI in cataract patients.
• OSI correlated with wavefront error and full width at half maximum (p < .05).
• FSI showed no significant relationship with wavefront error or full width at half maximum (p > .05).

Conclusions:

• The adapted FSI is a reliable index for measuring intraocular scattering.
• FSI is less affected by ocular aberrations compared to OSI.
• FSI is applicable to conventional double-pass instruments in clinical settings.