Practical takeaway

Key result Anterior-chamber depth segmentation was incorrect in 34.78% of eyes. Predicted refractive change nevertheless stayed within ±0.50 D for every formula.

An ICL did not make the theoretical calculation of a future IOL clinically unstable. Automatic IOLMaster 700 segmentation should still be inspected, particularly when vault is low.

How it was tested

This prospective theoretical study included 92 eyes measured before ICL implantation and one year later. Predicted refraction for the same hypothetical IOL was calculated with ten variants of contemporary formulas.

What changed after ICL

  • Measured axial length increased 0.02 mm, K2 0.08 D and lens thickness 0.26 mm.
  • Anterior-chamber depth decreased 0.28 mm.
  • Segmentation errors were linked to low vault; the 0.491-mm threshold was derived in the same sample.
  • SRK/T and integrated Barrett Universal II most often stayed within ±0.25 D.

What the study does not prove

No cataract extraction was performed and actual postoperative refraction was not measured. The natural lens and ICL remained in place, so the study assessed change in a calculated prediction only. Findings also come from one biometer model and need external validation.