CHOROIDAL STRUCTURE IN RP

Purpose: To investigate the choroidal structures in the enhanced depth imaging optical coherence tomographic images in eyes with retinitis pigmentosa (RP) and to determine correlations between the choroidal structures and visual functions. Methods: The enhanced depth imaging optical coherence tomographic images of 100 eyes with typical RP and 60 age-, sex-, and axial length–matched normal eyes were binarized using ImageJ. The cross-sectional luminal and stromal areas of the inner and outer subfoveal choroid of 1,500-µm width were measured. The inner choroid included the choriocapillaris and medium vessel layer, and the outer choroid included the larger vessel layer. Results: In the inner choroid, the luminal area and the ratio of luminal/total choroidal area (L/C ratio) were significantly smaller in RP than in controls (P = 0.010, P < 0.001, respectively), whereas the stromal area was not significantly different (P = 0.114). The inner choroidal L/C ratio was significantly correlated with the best-corrected visual acuity, mean deviation, foveal sensitivity, width of the ellipsoid zone, and central foveal thickness in RP after adjusting for the axial length, age, and sex (all P < 0.005). Conclusion: The significant correlations between the inner choroidal structures and the visual functions and retinal structures indicate that the choroidal structures are altered in association with the progression of RP