J Retin.  2022 May;7(1):9-15. 10.21561/jor.2022.7.1.9.

Optical Coherence Tomography Angiography in Refractory Diabetic Macular Edema

• Lee HJ
• Hwang DDJ

• KMID: 2552159
• DOI: http://doi.org/10.21561/jor.2022.7.1.9

Abstract

Purpose
To evaluate the characteristics of patients with diabetic macular edema (DME) unresponsive to intravitreal bevacizumab injection using optical coherence tomography angiography (OCTA) taken before the administration of combined intravitreal bevacizumab and posterior subtenon triamcinolone injection.
Methods
This retrospective study included 16 eyes of 16 patients with DME that did not respond to intravitreal bevacizumab injection. We defined refractory DME as ≥ 300-μm CMT (central macular thickness) and a < 30-μm CMT reduction after three consecutive bevacizumab injections or increased CMT after two consecutive bevacizumab injections. Vessel density (VD) of the superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP) was measured using OCTA before combination therapy with intravitreal bevacizumab and posterior subtenon triamcinolone injection. We evaluated whether there are factors that can predict treatment response to combination therapy.
Results
VD of the SCP and DCP before injection was 38.10% ± 2.67% and 36.08% ± 3.45%, respectively. The larger the VD difference between the SCP and DCP before injection (SCP VD–DCP VD), the greater the decrease in CMT and improvement in visual acuity 1 month after injection (p = 0.035, p = 0.025, respectively).
Conclusions
OCTA in patients with DME unresponsive to bevacizumab injection showed that a greater VD difference between the DCP and SCP was associated with a greater decrease in CMT and improvement in visual acuity after combined intravitreal bevacizumab-subtenon triamcinolone injection therapy.

Keyword

Diabetic retinopathy; Intravitreal injections; Macular edema; Tomography; optical coherence; Triamcinolone acetonide