Evaluation of the Accuracy of Two Marking Methods and the Novel toriCAM Application for Toric Intraocular Lens Alignment

J Refract Surg. 2018 Mar 1;34(3):150-155. doi: 10.3928/1081597X-20180115-03.


Purpose: To compare the accuracy of two common reference marking methods for toric intraocular lens alignment before and after using the novel toriCAM application.

Methods: In this prospective, randomized study, 22 participants were randomly allocated to two groups, either freehand or slit-lamp-assisted marking. Corneal markings at 0° and 180° were made using either method. The toriCAM application on a smartphone was then used to assess the rotational alignment of these markings and compared to the actual alignment as measured by the Zaldivar calipers on the iTrace Topographer (Tracey Technologies, Houston, TX) as a reference. The errors in marking with and without using the application were analyzed for all patients in each cohort and determined for each marking method.

Results: Twenty eyes of 11 patients were marked using the freehand method and 20 eyes of the other 11 patients were marked using the slit-lamp method. The mean absolute error of all markings before toriCAM adjustment was 3.18° ± 2.22°. This was significantly reduced to 1.28° ± 1.34° after using the application (P < .001). This improvement was also noted separately in the freehand and slit-lamp groups. Comparison of the freehand and slit-lamp methods did not show any statistically significant difference in accuracy at both time points.

Conclusions: The novel toriCAM application is able to significantly improve the accuracy of reference marking for both freehand and slit-lamp methods. [J Refract Surg. 2018;34(3):150-155.].

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Astigmatism / prevention & control
  • Female
  • Fiducial Markers*
  • Humans
  • Lens Implantation, Intraocular / methods*
  • Lenses, Intraocular*
  • Male
  • Middle Aged
  • Phacoemulsification / methods*
  • Prospective Studies
  • Pseudophakia / physiopathology
  • Reference Values
  • Refraction, Ocular
  • Reproducibility of Results
  • Visual Acuity / physiology