Abstract
Purpose :
Alterations of the foveal central bouquet (CB) consisting of Muller cell and cone photoreceptors have been described in association with vitreomacular traction and epiretinal membrane (ERM). CB changes have not been previously described in the setting of cystoid macular edema (CME). This study uses spectral domain optical coherence tomography (SD-OCT) to test the hypothesis that CB abnormalities (CBA) may be present in early CME, providing pathophysiologic insight into various causes of CME.
Methods :
This is a retrospective, consecutive case series of 45 eyes from 33 patients with new central CME from Diabetic Macular Edema (DME), Central Retinal Vein Occlusion (CRVO), Irvine-Gass Syndrome (IG), Uveitis, and Retinitis Pigmentosa (RP). Eyes with foveal CME present for less than one month were included. Eyes with ERM were excluded. CBA was defined as any thickened or ill-defined appearance to the external limiting membrane (ELM), ellipsoid zone (EZ) or interdigitation zone, in a ~100 um circular area in the central fovea, with or without subretinal fluid (SRF) or vitelliform material. Comparisons were made using Students t-test and Fisher’s exact test.
Results :
CBA was observed in 73% (8/11) of Uveitis eyes, 60% (3/5) of IG eyes, 67% (6/9) of CRVO eyes, and in no cases of DME or RP. Among all groups, eyes with CBA had significantly greater baseline central retinal thickness (CRT) (p=0.014) vs. eyes without CBA. Compared to eyes without CBA, those with CBA had significantly higher rates of SRF (p<0.001), outer nuclear layer (ONL) cysts (p=0.017), having larger ONL vs. inner nuclear layer (INL) cysts (p<0.001), and having a large central subfoveal ONL cyst (p<0.001). There was no association between CBA and worse visual acuity; however, larger ONL vs. INL cysts (p=0.012), and SRF fluid (p=0.004) were associated with worse visual acuity.
Conclusions :
Early CME from CRVO, Uveitis, and IG may be associated with CBA. Eyes with CBA had significantly more subfoveal outer retinal changes, and greater CRT, compared to eyes without CBA. These findings highlight that causes of CME associated with inflammatory pathophysiology and significant retinal thickening may involve Muller cell and/or cone photoreceptor dysfunction in the central fovea.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.