Abstract
Purpose :
To evaluate, non invasively, modifications of specific retinal inflammatory biomarkers (intraretinal hyper-reflective spots-HRS; subfoveal neuroretinal detachment-SND; and increased foveal autofluorescence-IFAF) after intravitreal steroid or anti-VEGF treatment in diabetic macular edema (DME).
Methods :
Retrospective analysis of images and clinical charts of 72 eyes(72 patients) with naive center-involving DME who underwent either a single intravitreal dexamethasone implant-IVDex (23 eyes) or 3 monthly intravitreal ranibizumab-IVR injections(49 eyes) . All patients had good quality fundus color photo, spectral-domain(SD)-OCT and fundus autofluorescence (FAF), best corrected visual acuity (BCVA) recorded before and one month after treatment. The following parameters were evaluated on SD-OCT linear B-scan at 0°: total number of HRS counted in the area of 3000 µm centered on the fovea and presence of SND. FAF images were evaluated for area of IFAF. All measurements were performed by 2 masked graders, independently. t-Student test for paired data was used for evaluation of changes induced by treatment, whereas analysis of covariance was used for comparison of changes between two treatment groups. Pearson’s linear correlation coefficient was used to evaluate relationship between BCVA or central retinal thickness (CRT) and HRS, SND and IFAF.
Results :
BCVA and CRT significantly improved in all patients, (p<0.05 for both groups). Mean number of HRS decreased by 32,4±12,1spots after IVDex and 24.9±14spots after IVR, (p<0.001 for both). HRS decrease was significantly higher in IVDex treated eyes vs IVR treated eyes, p=0.03. SND resolved in 85.7% of IVDex treated eyes (p=0.014) and in 53.3% IVR treated eyes(p=0.005). Mean iFAF area decreased by 0,27±0,23 mm2 after IVDex and 0,17±0,10 mm2 after IVR, (p<0.05 for both). A significantly higher decrease in IFAF area was observed in IVDex vs IVR treated eyes, p=0.017. Higher baseline values of HRS and IFAF area and presence of SND were correlated with better functional and morphologic outcome in IVDex vs IVR treated eyes.
Conclusions :
HRS, SND and increased FAF may represent new clinical biomarkers of chronic inflammation in DME. Higher number of HRS, larger area of iFAF and presence of SND may indicate a significant inflammatory condition in DME, and thus more responsive to a “broad spectrum” anti-inflammatory treatment.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.