Correlation between fluorescein angiography and spectral-domain optical coherence tomography in the diagnosis of cystoid macular edema

Aims To compare the ability to detect cystoid macular edema (CME) and its late complications between spectral-domain optical coherence tomography (SD-OCT) and fluorescein angiography (FA).

Methods Retrospective, observational, case series. 85 Eyes who had FA and SD-OCT performed on the same day at first visit and/or at follow-up visits were included. FA and SD-OCT images were evaluated for the evidences associated with CME and other structural changes of macula. FA and SD-OCT images were then superimposed to determine the relationships of diagnostic features between the two images. Main outcome measure was the correlation between FA and SD-OCT findings of macula in patients with CME.

Results The common causes of CME in our study were retinal vein occlusion (RVO, 63%), diabetic retinopathy (DR, 21.18%) and posterior uveitis (3.53%). CME associated with RVO, age-related macular degeneration and DR were missed by FA in 18.52%, 33.33% and 33.33% of cases, respectively. Subretinal fluid was undetectable by FA in 54.55%, which mainly were in the RVO group. SD-OCT gave earlier CME diagnosis than FA in three (3.53%) eyes. Residual CME at follow-up visits were missed by FA in one (1.18%) eye. Late complications of long-standing CME (secondary macular hole (two eyes), secondary subretinal fluid (five eyes), retinal pigment epithelium detachment (one eye) and photoreceptor atrophy (one eye)) were detectable only by SD-OCT.

Conclusions SD-OCT demonstrated greater sensitivity than FA in detecting CME, particularly those associated with RVO, DR and age-related macular degeneration. SD-OCT was also more sensitive than FA for detecting subretinal fluid and late complications of long-standing CME.