Short-term outcomes in patients with center-involving diabetic macular edema after a single dose of intravitreal bevacizumab

Abstract

Background A significant portion of diabetic macular edema (DME) is refractory to anti-vascular endothelial growth factor (anti-VEGF) agents. This study investigates morphological and functional outcomes to a single intravitreal bevacizumab (IVB) injection in patients with center-involving DME (ciDME) at 4–6 weeks and compares treatment responders and non-responders based on spectral domain optical coherence tomography (SD-OCT) features. Methods IRB approved observational, retrospective chart review of patients with ciDME, identified by ICD-10 code, who received IVB and underwent baseline and 4–6 weeks follow-up SD-OCT imaging between January 1, 2016 and January 19, 2021. Patients who had received previous treatment with anti-VEGF or intraocular steroids within 1 year were excluded. Variables included best-corrected visual acuity (BCVA), central subfield thickness (CST) and total macular volume (TMV). Eyes were classified as responders if CST reduction was greater than 10%. OCT scans were graded qualitatively by two masked graders using Imagivault software. Paired Student’s t-tests, Wilcoxon signed rank tests and Chi-Square tests were used for analysis. Results A total of 334 prospective subjects were identified, and after applying exclusion criteria 52 eyes from 46 patients (mean age 64.22 ± 8.12 years, 58.7% male) were included. Mean BCVA did not significantly change with treatment, 63.9 ETDRS letters (~ 20/50) at baseline and 65.9 ETDRS letters (~ 20/50) post-treatment (p = 0.07). Mean CST decreased from 466 ± 123 μm at baseline to 402 ± 86 μm post-treatment (p < 0.001). 22 (42.3%) of eyes were categorized as responders and 30 (57.7%) as non-responders. Average change in CST from baseline in responders was -164 μm (p < 0.001) and + 9 μm in non-responders (p = 0.47). Vitreomacular adhesion (VMA) was more prevalent in non-responders (28.7% vs. 4.8%, p = 0.03). In addition, cyst location in the inner nuclear layer (INL) was present more frequently in responders (95.5% vs. 73.3%, p = 0.037) as was subretinal fluid (45.5% vs. 13.3%, p = 0.01). Conclusion The short-term response to a single IVB was sub-optimal with structural but no functional improvements. Greater baseline CST, presence of INL cysts and subretinal fluid may represent factors indicative of a better treatment response.

Evaluation of bioclinical markers to predict short term response to intravitreal anti-VEGF in treatment-naive diabetic macular edema and the “Fried Egg” sign : a novel OCT feature

“…(6, 8, 11) A recent study by Turski A et al also showed a short term good response for anti-VEGF with higher CSFT. (11) We had a similar response to anti-VEGF treatment with higher CSFT and patients with SRF more likely to show good response at their rst and second injection.…”

“…(8) Several clinical and optical coherence tomography (OCT) markers have been studied to predict poor responders, namely hyperre ective dots (HRD), suspended scattering particles in motion (SSPiM), size and type of cysts, disorganization of inner retinal layers(DRIL), foveal vascular density and area of foveal avascular zone. (9)(10)(11)(12) Suspended scattering particles in motion (SSPiM) is a newly described OCT marker which is characterized by the presence of ow signals corresponding to non-vascular components on en face optical coherence tomography angiography (OCTA). The incidence and its response to treatment is not well understood.…”