To determine whether scanning laser ophthalmoscope in the retromode (RM-SLO) is useful to evaluate the extent of diabetic macular edema (DME) and its functional characteristics.
Comparative case series of 37 eyes (27 patients with diabetes). Inclusion criteria were: center involving DME determined by optical coherence tomography; RM-SLO, optical coherence tomography, fluorescein angiography (FA), and microperimetry performed on the same day; no significant media opacities. Two masked retinal specialists independently graded all images. The full extent of DME areas and two grades (small and large) DME areas were separately evaluated. The relationship between the DME extent obtained by RM-SLO and FA was assessed by Pearson correlation coefficient, intraclass correlation coefficient, and Bland–Altman plot. T-test was used to compare DME extent to central retinal thickness and macular sensitivity.
The values of RM-SLO from the right and left prospective were highly correlated in the evaluation of the extent of DME (rho = 0.99, P < 0.0001). Mean DME area on RM-SLO was 5.7 + 5.6 mm2 (range, 0.3–18.2 mm2); mean DME area on FA was 6.4 + 5.9 mm2 (range, 0.3–19.7 mm2). The correlation between RM-SLO and FA in the evaluation of DME extent was highly significant (rho = 0.97, P < 0.0001), even when DME extent was divided in 2 major areas (intraclass correlation coefficient >0.8, P < 0.0001). The correlation between retinal sensitivity and DME area (RM-SLO) was significant (rho = −0.61, P = 0.0003).
The extent has become an important parameter for monitoring DME, with or without treatment. The extent of DME well correlates with functional data, mainly retinal sensitivity. Retromode SLO can be reliably and easily used in the evaluation of DME extent, avoiding the use of invasive FA.
Scanning laser ophthalmoscope in the retromode easily and noninvasively evaluates different aspects of diabetic macular edema, including the extent. The extent may become a new parameter in the clinical evaluation of diabetic macular edema allowing to identify new phenotypes and more tailored treatment to obtain better functional results.
*Department of Ophthalmology, University of Padova, Padova, Italy; and
†Fondazione G. B. Bietti, IRCCS, Roma, Italy.
Reprint requests: Edoardo Midena, MD, PhD, Department of Ophthalmology, University of Padova, Via Giustinianiani 2, Padova 35128, Italy; e-mail: email@example.com
Partially presented at the XXVIII Meeting of the Club Jules Gonin, Reykjavik Iceland, June 20–23, 2012.
None of the authors have any financial/conflicting interests to disclose.