Accuracy and reproducibility of axial length measurement in eyes with silicone oil endotamponade

Aim: To assess the accuracy and signal quality of axial length measurements by partial coherence laser interferometry (PCI) for optical biometry in eyes with conventional silicone oil (SO) or heavy silicone oil (HSO) as endotamponade. Methods: We included 26 eyes with SO endotamponade (SO, n = 15; HSO, n = 11) using a Zeiss IOLMaster for measurement of axial length the day before and at least 6 weeks after SO removal. We analysed the intra-individual deviation between both measurements and signal-to-noise ratio (SNR) as a marker for signal quality. We included 16 contralateral eyes without history of vitreoretinal surgery to act as the control group. Results: The mean axial length was 24.76 (SD 2.07) mm (SO 24.63 (SD 2.12) mm, HSO 24.93 (SD 2.10) mm, control 24.95 (SD 2.61) mm) before and 24.75 (SD 1.96) mm after oil removal with a mean intra-individual deviation of 0.13 (SD 0.11) mm (SO 0.13 (SD 0.12) mm, HSO 0.13 (SD 0.09) mm, control 0.02 (SD 0.01) mm) while SNR at baseline was 5.7 (SD 3.5) (SO 6.6 (SD 4.0), HSO 4.4 (SD 2.2), control 8.6 (SD 3.9)). Conclusion: In our analysis, optical biometry using PCI generated results with acceptable accuracy and signal quality for measurement of axial length in SO-filled eyes.