Abstract
Purpose: :
The aim of the study was to correlate fluorescein angiographic (FA) and optical coherence tomography (OCT) findings with the functional loss assessed with microperimetry in patients with untreated diabetic macular edema (DME).
Methods: :
Twenty eyes of 19 diabetic patients with diabetic macular edema were evaluated in this prospective case series. In all patients, ETDRS best corrected visual acuity was assessed, automated fundus tracking microperimetry (MP; MP1, Nidek Spa), spectral domain OCT (Cirrus, Zeiss Meditec) and fluorescein angiography (HRA2, Heidelberg Engineering) were performed. Microperimetric findings were than projected onto the corresponding late phase fluorescein angiographic images using Computer Assisted Design (CAD) software and further correlated to morphologic changes in SD-OCT.
Results: :
In all patients, SD OCT allowed for direct correlation of morphologic retinal changes to functional assessed in microperimetry, as well as to pathophysiological imaged by FA. A functional deficit secondary to diabetic retinal alterations assessed by microperimetry did not correlate to the corresponding amount and pattern of dye leakage seen in late phase FA images. However, morphologic findings in OCT, such as location and volume of cysts or presence of neuro-retinal detachment, had a direct predictive value for functionality. Furthermore, the level of integrity of the neuro-sensory retinal layers imaged by OCT corresponded to functional changes in MP in a more reliable way than the corresponding vascular leakage in FA.
Conclusions: :
Leakage as seen in FA alone does not reflect the presence and extent of functional loss in patients with diabetic macular edema. This is probably due to FA’s lack of ability to visualize morphologic alterations, such as neuro-retinal detachments and disturbed retinal layer integrity. Microperimetry proved to be the most essential diagnostic tool in evaluating a retinal functional loss secondary to diabetic retinopathy.
Keywords: diabetic retinopathy • imaging/image analysis: clinical • perimetry