Abstract
Purpose: :
To determine what limits optical coherence tomography (OCT) image quality in silicone oil (SO)-filled eyes. Poor OCT image quality in SO-filled eyes limits post-operative monitoring and timely treatment of SO-associated problems such as proliferative vitreoretinopathy and macular edema. Because OCT requires matching of the optical properties of the reference and sample arms, OCT instruments employ various techniques to compensate for the optical dispersion of the vitreous. We hypothesized that the quality limitation in SO-filled eyes is due to differences in optical dispersion between SO and vitreous.
Methods: :
Fourteen eyes of 7 patients, who had vitrectomy and SO tamponade in 1 eye, were imaged with custom-made, ultra-high resolution SDOCT (depth resolution ~3µm). The fellow eye with native vitreous served as control. Dispersion compensation (DC) was introduced in the software for both real-time display and post-processing. The DC coefficients were tuned for best depth resolution.
Results: :
Tuning the second-order DC coefficient (C2) consistently improved images in all SO-filled eyes. The difference in C2 needed to produce best depth resolution was consistent and significant between SO-filled eyes and control eyes (p<0.001).
Conclusions: :
Differences in optical dispersion between SO and vitreous limited OCT image quality in SO-filled eyes. Adjustment in the second-order dispersion compensation coefficient was critical in achieving best OCT depth resolution when imaging through SO and significantly improved the clinical utility of SDOCT in SO-filled eyes.
Keywords: imaging/image analysis: clinical • image processing • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)