Reproducibility of intraocular lens decentration and tilt measurement using a clinical Purkinje meter

To determine the reproducibility of intraocular lens (IOL) decentration and tilt measurements with a new Purkinje meter instrument.

Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.

After pupil dilation, images of pseudophakic eyes with a plate-style IOL (Akreos Adapt) were obtained using a recently developed Purkinje meter. Intraocular lens decentration and tilt were evaluated by analyzing the captured images using a semiobjective method by marking the reflexes in the images and automatic calculation using a dedicated software program. In study 1, examiner 1 examined the eyes first followed by examiner 2. Ten minutes later, examiner 1 performed a second measurement, after which the intraexaminer and interexaminer reproducibility were determined. In study 2, a Purkinje meter was used to measure pseudophakic eyes with slitlamp finding of clinical IOL decentration, IOL tilt, or both. The results were compared with retroillumination photographs and slitlamp findings.

In study 1, there was high intraexaminer reproducibility for decentration (r = 0.95) and tilt (r = 0.85) and high interexaminer reproducibility for decentration (r = 0.84) and tilt (r = 0.75). In study 2, even in extreme cases of decentration and/or tilt, the Purkinje meter measurements were possible and appeared to correlate well with slitlamp findings.

Acquisition of images in pseudophakic eyes with the Purkinje meter was simple and rapid. The method was highly reliable for 1 examiner and between 2 examiners.