Purpose
To relate the baseline anatomic features on spectral domain optical coherence tomography (SD-OCT) to visual acuity in patients with diabetic macular edema (DME).
Methods
Retrospective observational case series of patients with DME attending a retina clinic in (Belfast, UK). Best-corrected visual acuity (BCVA) was available along with SD-OCT of the macular retina. SD-OCT images were graded for intra retinal fluid (IRF) localisation and shape of DME, presence and location of hyper reflective dots and foci by retinal layer, intactness of external limiting membrane (ELM), ellipsoid zone (EZ), and the outer hyper reflective bands constituting Bruch’s, RPE and choriocapillaris complex, and the vitreomacular interface. Retinal thickness at the fovea(RTF) and at site of maximum retinal thickness(MRT) were measured. Statistical analysis consisted of Pearson’s coefficient to test correlations between BCVA and OCT metrics, one way<br /> analysis of variance (ANOVA) for associations between BCVA and categorical OCT features and chi square for associations between structural alterations and types of<br /> DME.
Results
60 eyes were analysed. Of the OCT metrics, MRT was most significantly associated with BCVA (p=0.006,). BCVA also correlated highly with categorical OCT parameters. The strongest associations with distribution of IRF was the intactness of the Bruch’s RPE complex, (chi square 17.73 p=0.007). The regression model with BCVA as the dependent variable entered the following explanatory variables (age, location of the IRF, evidence of vitreomacular abnormality, choroidal thickness at the fovea and disruption of Bruch's RPE complex) into the model with an adjusted R2 of 0.38.
Conclusions
Our study identified specific tomographic features as important biomarkers for the prediction of functional and morphological outcomes in DME.