Reproducibility of intraocular lens decentration and tilt measurement using a clinical Purkinje meter
Purpose: To determine the reproducibility of intraocular lens (IOL) decentration and tilt measurements with a new Purkinje meter instrument. Setting: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. Methods: 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. Results: 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. Conclusions: 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. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.