Choroidal thickness and vascular density after rhegmatogenous retinal detachment

To study choroidal thickness (CT) and luminal areas of choroidal vessels in the setting of fovea-off rhegmatogenous retinal detachment (RRD).

Twenty-seven eyes with RRD were prospectively studied before and after pars plana vitrectomy and SF6 tamponade, using swept-source optical coherence tomography (SS-OCT). CT was measured pre- and postoperatively both subfoveally and in attached macular areas. Postoperatively, the CT in previously detached or attached Early Treatment Retinopathy Diabetic Study (ETRDS) macular areas and the choroidal luminal areas were assessed.

The preoperative median subfoveal CT of 260 μm (interquartile range (IQR) = 151) was significantly reduced to 200 μm (IQR = 110) 1 month postoperatively (p < 0.001). Corresponding to attached macular areas, the preoperative median CT of 184 μm (IQR = 116) was significantly reduced to 155 μm (IQR = 103) 1 month postoperatively (p = 0.03). No significant changes in CT occurred from 1 to 12 months postoperatively, either in previously detached, median 163 μm (IQR = 74) to 173 μm (IQR = 127), (p = 0.484), or in attached, 148 μm (IQR = 110) to 159 μm (IQR = 142), (p = 0,766) EDTRS areas. Median luminal areas of inner choroidal microvasculature and large choroidal vessels were 58.5% (IQR = 1.4) and 61.4% (IQR = 2.2) at 1 month, respectively, and stayed unchanged until 12 months postoperatively.

CT reduction 1 month after vitrectomy for fovea-off RRD was more pronounced subfoveally than beneath attached macular areas. This finding could represent a normalization of a subfoveal choroidal swelling due to increased fluid absorption during RRD. From 1 month and onwards, the CT and luminal areas remained unchanged.