Accuracy Of Iol Power Calculation In Eyes With A Myopic Target

To compare the results of nine formulas and find the most accurate one when targeting myopia between -2.00 D and -3.00 D.

A retrospective study conducted in Clinica Oculistica of Hospital San Martino.

A study at San Martino Hospital in Genoa, Italy, from Nov 2022 to Nov 2023 focused on myopic patients undergoing phacoemulsification and IOL implantation with a -2.50 to -3.00 diopters target. Patients meeting preoperative criteria, excluding certain conditions, were included. Optical biometry with OA-2000 determined ocular parameters. Same IOL (iSert 255, Hoya®, Japan) was implanted. IOL power calculations utilized various formulas, including Barrett Universal II, EVO 2.0, Haigis, Hoffer Q, Hoffer QST, Holladay I, Kane, and SRK/T with constants optimized for accuracy. Refractive outcomes were compared using Eyetemis software, assessing trueness, precision, and accuracy of spherical equivalent prediction error. 

The study analyzed 130 eyes (mean age 73.9 ± 8.8 years, 62.9% female) meeting inclusion criteria. Optimized constants for IOL power calculation were determined for various formulas. Statistical analysis showed no significant difference in spherical equivalent prediction error (SEQ-PE) among formulas but significant differences in precision and accuracy.Holladay 1 formula exhibited lower precision and accuracy compared to Kane, BUII, Hoffer QST and EVO 2.0 (p<0.01). 

Statistically significant differences emerged under the 0.50 D threshold between the BUII and the Holladay 1 (p<0.01); further statistically significant differences were present under 0.75 D threshold as BUII and the Hoffer QST formulas were superior to Holladay 1 (p<0.05)

A good accuracy in intentional myopic target is achievable thanks to the use of newer formulas like EVO 2.0, Kane and Hoffer QST, and older formulas like Barrett UII, Haigis and Hoffer Q.

Holladay 1 and SRK/T show less performing results and, thus, other formulas should be preferred.