Abstract:AIM: To explore and compare the effect of corneal epithelial thickening on predictability of 7 common intraocular lens(IOL)calculation formulas: the Barrett Universal II, Haigis, Holladay 2, Kane, EVO, Hill-RBF and SRK/T.
METHODS: Patients undergoing phacoemulsification and IOL implantation surgery from July 2023 to September 2023 were included. Before the surgery, biometry data was obtained by IOLMaster 700 and epithelial thickness was determined using optical coherence tomography. A monofocal IOL(Hoya iSert 250)was inserted into the capsular bag. The postoperative refraction was measured 3 mo after the surgery. The median epithelial thickness of 57.0 μm was set as a grouping criterion: ≥57.0 μm(thick group)and Symbol|@@57.0 μm(thin group). The percentage of eyes within prediction errors of ±0.25 D, ±0.50 D, ±0.75 D and ±1.00 D, mean absolute error(MAE), and median absolute error(MedAE)were reviewed.
RESULTS: Fifty-nine eyes of 59 patients(34 females, 25 males, mean age 68.85±8.71 y)were included in the study. The thin group included 30 eyes and the thick group included 29 eyes. Among all 59 eyes, Barrett Universal II showed the highest percentage of prediction error within ±0.50 D(83%), followed by Hill RBF(81%). Kane(71%)and EVO(73%)exhibited the lowest percentages. When calculating the percentage of eyes with absolute error within ±0.25 D using seven IOL calculation formulas, most formulas showed significant declined accuracy in the thick group compared with the thin group(U=6.00, PSymbol|@@0.05). Hill RBF showed better accuracy in eyes with thickened epithelium, with higher percentage of prediction error within ±0.25 D(52%)and ±0.50 D(83%).
CONCLUSION: The accuracy of IOL calculation is associated with corneal epithelium thickening. Hill-RBF has better validity in eyes with thickened corneal epithelium.
