PURPOSE: To evaluate the accuracy of the measurements provided by a Scheimpflug camera combined with partial coherence interferometry for intraocular lens (IOL) power calculation.
SETTING: I.R.C.C.S.-G.B. Bietti Foundation, Rome, Italy.
DESIGN: Prospective case series.
METHODS: Consecutive patients scheduled for cataract surgery were enrolled. Preoperative biometry was performed with a Pentacam AXL. All patients received the same IOL (AcrySof SN60WF). Measurements were entered into the following formulas: Barrett Universal II, Emmetropia Verifying Optical 2.0, Haigis, Hoffer Q, Holladay 1, Holladay 2 with axial length adjustment, Kane, Ladas Super Formula (LSF) 2.0, Næser 2, Pearl-DGS, SRK/T, T2, and VRF. When refraction was measured at 1 month postoperatively, the mean prediction error (PE), the median absolute error (MedAE), and the percentage of eyes with a PE within ±0.25, ±0.50, and ±1.00 diopter (D) were calculated after constant optimization.
RESULTS: Ninety-one eyes of 91 patients were analyzed. Comparison of the mean PE and MedAE did not reveal any statistically significant difference. However, the Pearl DGS formula achieved the lowest MedAE (0.19 D), followed by the LSF 2.0 (0.22). Twelve of the 13 formulas obtained a PE within ±0.50 D in at least 80% of eyes (range 80%-87%) and 7 of them in at least 85%. Twelve formulas yielded a PE within ±0.25 D in at least 50% of eyes (range 51%-64%).
CONCLUSIONS: All the investigated formulas performed well using the Pentacam AXL measurements. The newest Pearl DGS formula version and LSF 2.0 showed promising results.