Advances in retinal imaging for diabetic retinopathy and diabetic macular edema

Abstract

Diabetic retinopathy and diabetic macular edema (DME) are leading causes of blindness throughout the world, and cause significant visual morbidity. Ocular imaging has played a significant role in the management of diabetic eye disease, and the advent of advanced imaging modalities will be of great value as our understanding of diabetic eye diseases increase, and the management options become increasingly varied and complex. Color fundus photography has established roles in screening for diabetic eye disease, early detection of progression, and monitoring of treatment response. Fluorescein angiography (FA) detects areas of capillary nonperfusion, as well as leakage from both microaneurysms and neovascularization. Recent advances in retinal imaging modalities complement traditional fundus photography and provide invaluable new information for clinicians. Ultra-widefield imaging, which can be used to produce both color fundus photographs and FAs, now allows unprecedented views of the posterior pole. The pathologies that are detected in the periphery of the retina have the potential to change the grading of disease severity, and may be of prognostic significance to disease progression. Studies have shown that peripheral ischemia may be related to the presence and severity of DME. Optical coherence tomography (OCT) provides structural detail of the retina, and the quantitative and qualitative features are useful in the monitoring of diabetic eye disease. A relatively recent innovation, OCT angiography, produces images of the fine blood vessels at the macula and optic disc, without the need for contrast agents. This paper will review the roles of each of these imaging modalities for diabetic eye disease.

The Relationship Between Macular Cyst Formation and Ischemia in Diabetic Macular Edema

“…Larger FAZ areas have been observed in the superficial, deep, and summated capillary plexus in diabetic patients in several studies using OCT angiography (OCTA), which is one of the current retinal imaging methods and allows construction of microvascular flow maps. 24,25,26,27 Also, similar to our study, disorganization and loss of retinal capillaries was observed more precisely in the deep plexus with more severe DME in OCTA images. 28 Although enlargement of the cyst in both planes seems to be associated with macular ischemia, vertical enlargement and retinal thickness had a greater impact on the ischemic process.…”

Performance evaluation of two fundus oculi angiographic imaging system: Optos 200Tx and Heidelberg Spectralis

“…These results indicate that the imaging range of the Optos 200Tx is better than that of the Spectralis. Although the results of the present study suggest that the above two ultra-wide-angle equipment provide a comprehensive display of fundus lesions, including no perfusion area, microangioma, vascular leakage, neovascularization and retinal degeneration, when it comes to the peripheral retina, the Optos 200Tx was indicated to be more capable of displaying the above-mentioned fundus lesions ( 19 ). The Optos 200Tx is able to identify peripheral retinal lesions that are missed by the Spectralis, which is of great value for the guidance of clinical treatments, including laser therapy and intravitreal injection ( 19 ).…”

Telemedicine for diabetic retinopathy screening using an ultra-widefield fundus camera

“…Several prospective studies have shown very good correlation between different imaging modalities with UWF imaging. 15 Silva et al 16 have reported UWF imaging increased the identification of DR (38.4% vs 33.8%, P =0.0053) and vision threatening DR (14.5% vs 11.9%) compared to non-mydriatic fundus photography. Moreover, peripheral retinal lesions could be detected located outside the ETDRS 7-standard field in more severe assessment of the level of DR in 9% of patients and neovascularization elsewhere (NVE) which were not seen on ETDRS 7-field photography.…”