d

e

Fig. 3.12 (a, b) Color (a) and red-free (b) photographs of the posterior pole of a young diabetic patient with poor visual acuity, showing hyperemic disk with neovascularization, multiple radial superficial hemorrhages, a cotton wool spot adjacent to the fovea, and whitening of retinal vessels in the temporal side, from occlusive vasculitis. (c) FA of the posterior pole showing hyperfluorescence of the optic disk due to neovascularization of the disk, enlargement of the foveal avascular zone with amputation of the retinal vessels, and retinal ischemia temporally to the fovea. (d, e) EDI OCT horizontal (d) and diagonal (e) scans display reduced retinal thickness and disorganization of the retinal layers

3.2.3Fundus Photography

Fundus photography played a central role in the screening and monitoring of the evolution of DR. The diagnosis and grading of DME are assessed by the detection of its surrogate markers, such as hard exudates. Stereoscopic photos are employed in clinical trials for the assessment of clinically significant macular edema (CSME).

3.2.4Microperimetry

Fundus microperimetry permits an accurate evaluation of the macular sensitivity and fixation pattern and has been tested in patients with DME [30]. Morphological and functional correlations have been described between microperimetry and other different examination, including best-corrected visual acuity (BCVA), FA, OCT, and fundus autofluorescence [31–34]. Besides, the role of microperimetry is increasing as a useful tool in the monitoring of DME after different treatments [31–33].

c

Fig. 3.13 (a) Color fundus photograph showing microaneurysms and vascular ectasia surrounded by circinate lipid, consistent with vasogenic DME. (b) FA early frame of the posterior pole revealing multiple leaking microaneurysms scattered throughout the macula and a number of intraretinal hemorrhages. (c) EDI OCT shows cystoid macular edema, associated to a large central cyst, multiple smaller cystoid spaces, and irreversible changes in the IS-OS junction. The choroid is clearly visible, showing a reduced choroidal thickness

3.2.5Multifocal Electroretinogram

Multifocal electroretinogram (mfERG) is widely used to assess the functional activity of eyes with different pathologies and to monitor the effect of the therapy [35– 37]. A macular dysfunction has been detected in DME, and useful correlations within other diagnostic tools have been described.

3.2.6Other Imaging Under Investigation

Different examinations and correlations between imaging have been performed to improve the better understanding of the retinal anatomy and functional activity in DME, including fundus autofluorescence, macular pigment optical density, and scanning laser ophthalmoscopy (SLO) in the retromode and adaptive optics

[38–41].