Purpose: To investigate the choroidal thickness in eyes with tilted disk syndrome within/without posterior staphyloma.
Methods: Twenty-one eyes examined in 16 patients with tilted disk syndrome were included. The thicknesses of the choriocapillaris, the medium-to-large choroidal vessels, and total choroids found 1 mm and 3 mm superior and inferior to the fovea and in the area with the thinnest choroid were measured using enhanced-depth imaging optical coherence tomography or high-penetration optical coherence tomography. The results were compared with the findings on indocyanine green angiography.
Results: The mean thicknesses of total choroid found 3 mm and 1 mm inferior (114.3 μm ± 77.8 μm, 145.0 μm ± 85.9 μm) to the fovea were significantly thinner than those found superior (174.5 μm ± 89.7 μm, 145.0 μm ± 85.9 μm) to it. The minimal choroidal thickness of 80.5 μm ± 67.1 μm was obtained at a mean 1.04 mm below the fovea at the upper edge of the posterior staphyloma. The thickness of the layer of choriocapillaris was not significantly different according to the regions but the layer of medium-to-large choroidal vessels found 3 mm and 1 mm inferior to the fovea was significantly thinner than that found superior to the fovea. The ratio of choriocapillaris to medium-to-large vessels found 1 mm superior also was significantly smaller than those found inferior. The diameter of medium-to-large choroidal vessels on ICGA was not significantly different in the areas although less number of vessels were seen around the area inferior to the fovea.
Conclusion: In the eyes of patients with tilted disk syndrome, the choroid is thinnest at approximately 1 mm inferior to the fovea at the upper edge of the posterior staphyloma rather than at the bottom of the posterior staphyloma. Thinning of the layer of medium-to-large choroidal vessels seems to be associated with the thinning of choroid thickness.