Comparison of adaptive optics scanning light ophthalmoscopic fluorescein angiography and offset pinhole imaging

Abstract

Recent advances to the adaptive optics scanning light ophthalmoscope (AOSLO) have enabled finer in vivo assessment of the human retinal microvasculature. AOSLO confocal reflectance imaging has been coupled with oral fluorescein angiography (FA), enabling simultaneous acquisition of structural and perfusion images. AOSLO offset pinhole (OP) imaging combined with motion contrast post-processing techniques, are able to create a similar set of structural and perfusion images without the use of exogenous contrast agent. In this study, we evaluate the similarities and differences of the structural and perfusion images obtained by either method, in healthy control subjects and in patients with retinal vasculopathy including hypertensive retinopathy, diabetic retinopathy, and retinal vein occlusion. Our results show that AOSLO OP motion contrast provides perfusion maps comparable to those obtained with AOSLO FA, while AOSLO OP reflectance images provide additional information such as vessel wall fine structure not as readily visible in AOSLO confocal reflectance images. AOSLO OP offers a noninvasive alternative to AOSLO FA without the need for any exogenous contrast agent. 458-461 (1990). 21. T. Hara, M. Inami, and T. Hara, "Efficacy and safety of fluorescein angiography with orally administered sodium fluorescein," Am.

Adaptive Optics Ophthalmoscopy

“…In one patient with a central retinal vein occlusion, they showed regression of a microaneurysm in response to VEGF treatment. A related paper reporting on the same patient presented 5 different ways the AO can visualize an individual microaneurysms (Chui et al 2014). Fig.…”

“…Scale bar is 0.5 deg. (B) from (Chui et al 2014) This figure shows a close up of one location indicated by the dashed white box in (A) imaged using in 4 different modes in the same AOSLO system (B.i) fluorescein angiography (B.ii) confocal (B.iii) motion contrast (B.iv) offset pinhole. A video recorded with offset pinhole AOSLO can be seen here.…”

Human retinal microvascular imaging using adaptive optics scanning light ophthalmoscopy

“…Fluorescein angiography (FA), coupled with confocal AOSLO, has enhanced the success of imaging the retinal microvasculature of the macula (Fig. 1b) and peripapillary retina [21, 22]. Although confocal AOSLO FA is considered safe and has been used to show perfusion and non-perfusion of the retinal capillaries in healthy controls and patients with vasculopathies [23–25], it requires an additional light source for fluorescein excitation and administration of oral fluorescein, making it more invasive with some risk of patient discomfort and potential side effects such as nausea and itching.

Fig.

…”

“…Microvascular perfusion maps are generated by extraction of moving elements from registered nonconfocal AOSLO videos, such as the intravascular flow of erythrocytes against the background of static tissue [2]. Nonconfocal AOSLO imaging provides structural images and perfusion maps comparable to those of confocal AOSLO FA with additional structural information such as fine structural components of vascular walls [22]. Figure 2 shows in vivo visualization of retinal vascular mural cells (Fig.…”

Multilevel Segmentation of Fundus Images using Dragonfly Optimization

“…The early signs of diabetic retinopathy as manifested in retinal images include micro-aneurysms, hemorrhages and exudates. Clinicians commonly use retinal images for the screening differential diagnosis of retinal diseases such as retinal edema, diabetic retinopathy, age-related macular degeneration, malarial retinopathy, glaucoma, cataracts, exudates, lesions, prediction of strokes in hypertension patients and so on [2][3][4].…”