Intraocular Lens Power Calculations in Short Eyes Using 6 Formulas
Purpose
To compare the accuracy of refractive prediction of six IOL power calculation formulas in eyes with axial length (AL) ≤22 mm.
Methods
We will evaluate six IOL power calculation formulas: Hoffer Q, Holladay 1, Holladay 2, Haigis, Olsen, Barrett. Consecutive cases that had cataract surgery from January 2011 to August 2014 with AL ≤22 mm will be reviewed. Inclusion criteria are: 1) biometric measurements with Lenstar (Haag-Streit AG), 2) no previous ocular surgery or intraoperative or postoperative complications, and 3) postoperative best-spectacle corrected visual acuity of 20/30 or better. Manifest refraction will be obtained at 3 weeks or longer postoperatively. The refractive prediction error will be calculated as the difference between the actual refractive outcome postoperatively and the predicted refraction. Lens constants in each formula will be optimized. The median absolute refractive prediction error will be calculated.
Results
Currently we are in the process of reviewing and collecting data. Refractive prediction error and median absolute prediction error will be compared among formulas. The effect of anterior chamber depth and lens thickness on the accuracy of refractive prediction will be explored.
Conclusion
Accuracy of refractive prediction using these IOL power calculation formulas will be discussed.