Effectiveness, Sensitivity, and Specificity of Intraocular Lens Power Calculation Formulas for Short Eyes

OBJECTIVES: To compare intraocular lens (IOL) power calculation formulas in terms of absolute error (AE) and receiver operating characteristic curves in eyes with axial length (AL) shorter than 22.0 mm. MATERIALS AND METHODS: The data of hyperopic patients who underwent uneventful phacoemulsification with IOL implantation in MW-med Eye Centre, Cracow, Poland between October 2015 and June 2019 were retrospectively reviewed. IOL power was calculated using Holladay1, SRK/T, Hoffer Q, Holladay2, Haigis, and Barrett Universal II formulas. The power of the implanted lens was based on Hoffer Q. Three months after phacoemulsification, refraction was measured and AE was calculated. The percentage of patients with full visual acuity without any correction and the percentage of hyperopic patients was determined for each formula. Receiver operating characteristic curves with cut-off points for AL were drawn for each formula and the area under the curve was evaluated. RESULTS: Fifty-six patients (62 eyes) whose ocular AL ranged between 20.58 mm and 21.97 mm were included in the study. Hoffer Q formula yielded the lowest mean AE (0.09±0.08 D), the highest percentage of patients with full visual acuity without correction (75.8%), and the lowest rate of postoperative hyperopia (8.1%). However, the SRK/T formula had the largest area under the curve (0.667). CONCLUSION: The Hoffer Q formula gave the lowest level of AE in the study and seems to be recommendable for IOL power calculation for hyperopic eyes. Further studies are needed on the use of receiver operating characteristic curves in assessing the effectiveness of IOL power calculation formulas.