Best fit formula approach in delayed sequential bilateral cataract surgery.

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Surgical Technology

Background:

• Cataract surgery requires precise intraocular lens (IOL) power calculation.
• Choosing the optimal IOL formula for the second eye after bilateral surgery can be challenging.

Purpose of the Study:

• To determine if the best-fit intraocular lens (IOL) power formula derived for the first operated eye (BF1) is also the most accurate for the second eye (BF2).

Main Methods:

• Retrospective analysis of 152 patients undergoing delayed bilateral cataract surgery.
• Evaluation of seven different IOL power formulas (Barrett Universal II, Castrop, Haigis, Hoffer Q, Holladay 1, Kane, SRK/T).
• Comparison of mean and median absolute prediction errors (MAE/MedAE) for formula selection strategies.

Main Results:

• The best-fit formula for the first eye (BF1) matched the best-fit formula for the second eye (BF2) in 56% of cases.
• Using BF1 for the second eye resulted in a lower median absolute prediction error (MedAE) of 0.22 diopters compared to random formula selection (0.33 D).
• BF1 was less accurate than using the optimal formula for each eye separately (0.1 D).

Conclusions:

• The best-fit formula for the first eye (BF1) provides a more accurate IOL power prediction for the second eye than random selection.
• BF1 serves as a practical and reliable option when surgeons are uncertain about the best formula for the second eye.