Name

Évolution postopératoire des membranes épirétiniennes idiopathiques associées à des kystes intra-rétiniens selon la présence d'une diffusion sur l'angiographie à la fluorescéine préopératoire

Idiopathic epiretinal membranes may be associated with the presence of intraretinal cystoid spaces on preoperative optical coherence tomography. Its pathophysiology and the mechanisms leading to fluid accumulation are not yet fully understood. The purpose of the study was to describe the postoperative course of idiopathic epiretinal membranes according to the location of intraretinal cystoid spaces and the presence of preoperative blood-retinal-barrier breakdown on fluorescein angiography. 

A retrospective study of all consecutive eyes operated for primary epiretinal membranes over a 5-year period was conducted in Lariboisiere Hospital (Paris, France). Postoperative outcomes of eyes with intraretinal cystoid spaces and with leakage on fluorescein angiography were compared to those without leakage.

The records of 989 consecutive eyes who underwent vitrectomy for primary epiretinal membranes were reviewed: a total of 269 (27.2%) eyes showed preoperative intraretinal cystoid spaces. A postoperative follow-up period of at least 3 months was observed for 111 eyes that were included. A fluorescein angiography was performed preoperatively in 41 out of the 111 eyes. Preoperatively, cystoid spaces were observed in the inner nuclear layer only in 55 (49.5%) eyes, in the Henle fiber layer only in 23 (20.7%) eyes and both in the inner nuclear layer + Henle fiber layer in 33 (29.7%) eyes. Among the 41 eyes with preoperative fluorescein angiography, 25 (60.9%) eyes showed a leakage in the late phase. The proportion of leakage was significantly higher in epiretinal membranes with intraretinal cystoid spaces in the inner nuclear layer only (n=77.8%, 15/18, p=0.05). No leakage was observed in epiretinal membranes with foveoschisis. Six months after peeling, intraretinal cystoid spaces completely disappeared in 36.0% eyes. Regarding the 25 eyes imaged with leakage on preoperative fluorescein angiography, the postoperative visual acuity, the central macular thickness and the proportion of eyes with complete disappearance of intraretinal cystoid spaces did not differ from eyes without leakage (p=0.8, p=0.27 and p=0.9, respectively). An acute postoperative macular edema was observed in 8 (19.5%) eyes. Factors associated with acute postoperative macular edema were the presence of preoperative dye leakage (p=0.007) and preoperative location of cystoid spaces mainly in the inner nuclear layer or combined in the inner nuclear layer + Henle fiber layer (p=0.03).

Idiopathic epiretinal membranes associated with preoperative intraretinal cystoid spaces in the inner nuclear layer only or combined in the inner nuclear layer + Henle fiber layer appear to be associated with an increased risk of postoperative macular edema especially as they are associated with preoperative angiographic leakage secondary to breakdown of the blood-retinal-barrier. In contrast, the absence of leakage in most cases of epiretinal membranes associated with preoperative foveoschisis suppose a tractional mechanism with a lower incidence of post-surgical edema. 

In this series of eyes with idiopathic epiretinal membranes and cystoid spaces, preoperative fluorescein angiography showed leakage in 61 % of eyes. After peeling, eyes with leakage had functional and anatomic outcomes similar to those achieved with eyes without leakage. However, this presence of leakage on preoperative fluorescein angiography was associated with a higher risk of postoperative macular edema.