Refractive Predictability between Standard and Total Keratometry during the Femtosecond Laser-Assisted Cataract...

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Refractive Surgery

Background:

• Femtosecond laser-assisted cataract surgery (FLACS) is a modern approach to cataract removal.
• Intraocular lens (IOL) calculation accuracy is crucial for achieving desired visual outcomes.
• Monofocal IOLs with enhanced intermediate function offer a broader range of vision.

Purpose of the Study:

• To compare the accuracy of IOL calculation formulas using standard keratometry (K) versus total keratometry (TK) in FLACS.
• To evaluate formula performance with a specific monofocal IOL designed for enhanced intermediate vision.

Main Methods:

• Retrospective review of 125 eyes undergoing FLACS with a specific monofocal IOL.
• IOL refractive power calculated using Barrett Universal II, SRK/T, Haigis, and Holladay 2 formulas with both K and TK data.
• Absolute prediction error (APE) compared between predicted and actual postoperative refractive outcomes.

Main Results:

• Mean APE ranged from 0.29 to 0.39 diopters (D), with no significant difference between K and TK measurements across formulas.
• The Barrett Universal II formula yielded the lowest mean APE.
• 70-80% of patients achieved refractive outcomes within 0.5 D of the target.
• No statistically significant difference in the percentage of eyes within 0.5 D APE between K and TK.

Conclusions:

• Keratometric measurements, including posterior corneal curvature (TK), did not offer additional advantages for this specific IOL in FLACS.
• Standard keratometry (K) is sufficient for accurate IOL calculations with this IOL type in FLACS.