Comparison of Toric Intraocular Lens Calculations Between the IOLMaster 700 and Pentacam AXL

Abstract

Mohamed R. Gemae and Davin Johnson*

Purpose: To compare toric IOL (Intra Ocular Lenses) suggestions for power, toric, and IOL alignment between the IOLMaster 700 and Pentacam AXL (Axial Length).

Methods: This single-center retrospective chart review analyzed the charts of 62 patients (n=93 eyes) who underwent cataract surgery with a toric IOL between January and April 2022. For all patients, preoperative biometry was measured using both the IOLMaster 700 and Pentacam AXL, followed by IOL calculations performed on the Barrett Toric Online Calculator. The suggested IOL power and toric were defined as spherical equivalent power and toric power closest to plano and minimal residual astigmatism, respectively. Surgeons used lens suggestions as per IOLMaster 700 measurements, with Pentacam AXL being used as a confirmatory test. Patients with a history of laser refractive surgery, corneal disease, or in whom cataract density precluded measurements with either device were excluded. The outcome measures compared between devices were power, toric, and alignment suggestions.

Results: Power suggestions were within ± 0.5D in 94% of the eyes, and were identical in 54%. Toric suggestions differed by ± 1 toric step in 100% of eyes, and were identical in 67%. IOL alignment suggestions, however, were slightly more variable and differed by ± 5º in 38-55% of eyes. At one-month post-op, the mean absolute error in spherical equivalent was nearly identical between devices.

Conclusion: Our results show that IOLMaster 700 and Pentacam AXL show generally similar TORIC calculations with respect to spherical equivalent and suggested toric power. Small differences in alignment axis are frequent between the two devices and warrant further study.