Delayed Absorption of Subretinal Fluid after Retinal Reattachment Surgery and Associated Choroidal Features

Abstract

Purpose: The aim of this study was to investigate the incidence and associated clinical factors of delayed absorption of subretinal fluid (SRF) after surgery for rhegmatogenous retinal detachment.

Methods: This study involved 36 eyes of 36 consecutive patients who underwent successful surgery for rhegmatogenous retinal detachment. A complete ophthalmologic evaluation, including clinical fundus examination, optical coherence tomography, and indocyanine green angiography, was conducted before and after surgery. Delayed absorption was defined as the presence of residual concave SRF or an SRF bleb at 6 months after surgery. Clinical factors and choroidal features on indocyanine green angiography were compared according to the presence and absence of delayed absorption.

Results: Eighteen of 36 eyes (50%) showed delayed absorption. Macular involvement and worse preoperative visual acuity were significantly related to the presence of delayed absorption (p = 0.001 and p = 0.034, respectively). On indocyanine green angiography, preoperative choroidal vascular hyperpermeability was noted in 70% of eyes with delayed absorption and in 14% of eyes without it (p = 0.010).

Conclusions: Delayed absorption of SRF after retinal reattachment surgery was not rare, with a 50% of incidence in this study. Macula-off status was significantly related to the incidence of delayed SRF absorption, and choroidal features such as choroidal vascular hyperpermeability might be responsible in part, possibly through the resultant exudative property of choroid.

Keywords: Angiography; Choroidal vascular hyperpermeability; Optical coherence tomography; Rhegmatogenous retinal detachment.

Fig. 1. A case with delayed absorption of subretinal fluid (case 9). (A) Preoperative infrared fundus photography and optical coherence tomography imaging. (B) Preoperative indocyanine green angiography shows choroidal vascular hyperpermeability (arrows) around the macula. (C) Postoperative indocyanine green angiography of the same patient shows areas of hyperfluorescence around subretinal fluid (arrows). (D) A concave subretinal fluid bleb, which progressively decreased in height.

Fig. 2. A case with delayed absorption of subretinal fluid (case 16). (A) Preoperative infrared fundus photography and optical coherence tomography imaging. Preoperative indocyanine green angiography shows focal choroid vascular hyperpermeability (arrow) around the macula in the fellow eye (B) and in the affected eye with retinal detachment (C). (D) Postoperative 1-month indocyanine green angiography shows that preoperatively observed focal hyperfluorescence (arrow) remains in the fellow eye. (E) Patchy hyperfluorescence with choroidal vascular hyperpermeability are observed in the affected eye. (F) Concave subretinal fluid and a subretinal fluid bleb, which progressively decreased in height.

Fig. 3. Multimodal images of a case with persistent subretinal fluid (SRF) where postoperative photodynamic therapy resulted in complete resolution of SRF (case 36). (A) Preoperative infrared fundus photography and optical coherent tomography imaging show macula-off retinal detachment. (B) Indocyanine green angiography and optical coherent tomography taken 1 year postoperatively show concave SRF involving the fovea with thickened choroid. A mild degree of choroidal vascular hyperpermeability is noted from the temporal margin of the optic disk to the fovea. (C) A significant decrease in SRF was observed 3 months after photodynamic therapy. (D) Complete resolution of SRF was confirmed at 6 months after photodynamic therapy.