In this presentation, Dr. Graham Barrett provides his top 5 pearls for complex intraocular lens (IOL) calculations:

• High myopia: with Barrett Universal II, do not use modified axial length or modified constants.
• True K radial keratotomy (RK): taking partial history (post-RK refraction) into account improves outcomes.
• Measured posterior cornea provides the most accurate mode of True K, particularly if refractive history is unavailable.
• True K toric calculator v2.5 includes integrated K + keratoconus.
• Toric IOL selection after refractive surgery: custom True K toric calculator v2.5 is required for accurate prediction.