Abstract
Purpose: :
To determine the ability to detect normal vitreous structures, evolving posterior vitreous detachment (PVD) and related vitreoretinal changes with spectral domain optical coherence tomography/scanning laser ophthalmoscope (SD-OCT/SLO).
Methods: :
A consecutive series of patients symptomatic for PVD or with clinical diagnosis of PVD were imaged with SD-OCT/SLO (OTI Inc, Toronto, Canada, or Heidelberg Spectralis, Heidelberg Engineering, Germany). A total of 162 eyes of 93 patients were analyzed. The vitreous body, cortex and posterior hyaloid and their relationship to the retina surface were carefully analyzed both at the posterior pole and in the periphery. In the same eyes, static and dynamic ultrasound (US) was performed by a masked operator to determine the stage of PVD. Statistical analysis was performed to compare the clinical evaluation with the imaging findings.
Results: :
Out of 162 eyes PVD was diagnosed by clinical exam in 95 eyes versus in 93 eyes detected by the OCT (Kappa coefficient 0.79, p<0.0001). A partial PVD was detected much more frequently by the OCT than by ophthalmoscope (45 eyes versus 7 eyes, McNemar test p<0.001). The US was performed in a subset of 30 eyes. A high agreement was found between the US and the OCT for both complete PVD (Kappa coefficient=0.933, p<0.0001) and incomplete PVD (Kappa coefficient=0.91, p<0.001). Out of 162 eyes studied by SD-OCT, hyepereflectivity corresponding to the vitreous cortex was detected in 142 eyes, while a decreased reflectivity, corresponding to the posterior precortical pocket, was detected in 45 eyes. The effects of PVD, including traction and avulsion of retinal vessels and pits of the nerve fiber layers along the arcades, and fine changes in the foveal structure, could be reliably visualized in detail only with the OCT. In all these eyes the OCT instrument allowed improved visualization of the vitreoretinal relationship including some peripheral lesions such as retinal breaks and retinoschisis.
Conclusions: :
SD-OCT/SLO provides unprecedented in vivo information about the physiological and pathological vitreous structure; it allows an extremely detailed analysis of changes of the vitreoretinal interface, both at the posterior pole and in the periphery and it is particularly useful to define focal changes and PVD.
Keywords: vitreous • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)