Background: Understanding the changes that occur in the choroid is of paramount importance in various uveitis entities. B-scan ultrasonography and indocyanine green angiography can be used to study choroid. Currently, spectral-domain optical coherence tomography is used as the standard noninvasive technique to study the choroid by enhanced depth imaging. Our aim was to study the structural visibility of the choroid using spectral-domain optical coherence tomography in the same area of interest in patients with uveitis with posterior segment manifestations using conventional, enhanced depth imaging (EDI), and combined depth imaging (CDI) techniques.
Results: Fifty-eight (58) eyes of 48 patients between age group 9 and 82 years were confirmed cases of uveitis. Out of the 48 patients, 21 (43.75%) were males while 27 (56.25%) were females. Sixteen eyes (27.59%) had intermediate uveitis, 33 (56.9%) had posterior uveitis, and 9 eyes (15.51%) had panuveitis. For posterior vitreous, there was substantial agreement for all the three groups (kappa value of 0.77, 0.73, and 0.72 in groups 1, 2, and 3, respectively). For vitreo retinal interface and inner choroid, there was perfect interobserver agreement, and for outer choroid, there was substantial to almost perfect interobserver agreement (kappa value of 0.71, 0.81, and 0.86 in groups 1, 2, and 3, respectively). Chi-squared test was done to compare the three groups. The method of scanning had a significant effect on the visualization of posterior vitreous and the outer choroid (p < 0.01) and did not have an effect on the visualization of vitreoretinal interface, inner retina, outer retina, and inner choroidal layers (p > 0.05).
Conclusion: The CDI technique alone might provide a good structural visibility compared to normal and EDI scanning done separately in patients with uveitis with posterior segment pathology. CDI OCT technique is thus able to visualize all posterior structures in a single image in patients with uveitis with posterior segment manifestations.
Keywords: CDI; Combined depth imaging; EDI; Enhanced depth imaging; OCT; Optical coherence tomography; Spectral-domain optical coherence tomography (SD-OCT); Uveitis.