RESUMO
PURPOSE: To evaluate the effectiveness of intravitreal bevacizumab treatment in patients with diabetic macular edema (DME) by assessing retinal changes using AngioTool software (version 0.6a(02.18.14), National Cancer Institute, Bethesda, Maryland). METHODS: A total of 27 eyes in patients with treatment-naïve DME were included in this prospective study. OCT-A images with a scan area of 6 × 6 mm were obtained. The DME patients with a central macular thickness (CMT) of ≥300 µm received nine bevacizumab injections within 12 months. The demographic, systemic, and ocular parameters, including the best-corrected visual acuity (BCVA) and CMT, were assessed. Explant area, vessels area, vessels percentage area, total number of junctions, total vessels length, average vessels length, the total number of endpoints, and mean lacunarity in the superficial capillary plexus (SCP) were calculated by using AngioTool software. RESULTS: Twenty-nine eyes of DME patients were subjected to the final analysis. Bevacizumab treatment reduced CMT from 401.84 ± 84.54 µm to 328.93 ± 87.17 µm and improved BCVA from 65.18 ± 8.21 at baseline to 72.63 ± 7.43 letters among participants of the study. The anti-VEGF therapy showed no statistically significant changes in parameters calculated by AngioTool software in the study group of patients. CONCLUSION: The fixed-regimen intravitreal bevacizumab therapy was effective in treating DME. AngioTool software is an additional tool that could be used to assess vascular networks. However, the use of OCTA is unlikely to alter DME treatment regimens significantly or to find significant predictors. Perhaps using wide-angle devices or software will give a complete picture of the disease and prove to be more helpful.
RESUMO
PURPOSE: To evaluate the effectiveness of intravitreal bevacizumab treatment in patients with diabetic macular edema (DME) by assessing retinal changes using optical coherence tomography angiography (OCT-A). METHODS: This prospective study was performed in patients with treatment-naïve DME. The eyes of patients were imaged using a swept-source OCT system with a scan area of 6 × 6 mm. The DME patients with a central macular thickness (CMT) of ≥300 µm received nine bevacizumab injections within 12 months. The demographic, systemic, and ocular parameters, including the best-corrected visual acuity (BCVA), CMT, microaneurysm (MA) count, and foveal avascular zone (FAZ) area in both superficial capillary plexus (SCP) and deep capillary plexus (DCP), as well as vessel density in SCP, were assessed in the patients. In addition, the response (good or poor) of the DME eyes to bevacizumab treatment and the final visual acuity (BCVA of 75 letters) were analyzed. RESULTS: Seventy-seven eyes of DME patients were subjected to the final analysis. Bevacizumab treatment reduced CMT from 425.06 µm (±77.15) to 350.25 µm (±82.04) and improved BCVA by about 8.61 letters (from 64.73 to 73.34) in the patients. The mean number of MAs in SCP decreased from 3.51 ± 2.07 to 2.31 ± 1.15 (p < 0.001) and in DCP from 17.12 ± 11.56 to 12.21 ± 6.99 (p < 0.001), whereas the area of FAZ increased in SCP from 328.22 ± 131.38 to 399.70 ± 156.98 (p < 0.001) and in DCP from 571.13 ± 396.01 to 665.89 ± 412.77 (p = 0.001). The final BCVA letter score and CMT were statistically significant in both poor and good responders, as well as in BCVA < 75 and BCVA ≥ 75 groups. CONCLUSION: The fixed-regimen intravitreal bevacizumab therapy was effective in treating DME. Apart from noninvasive visualization of microvascular damage, OCT-A showed limited usefulness in predicting treatment response. Although the study showed that the number of MAs was significantly reduced during treatment, which is an OCT-A predictor of a good response to bevacizumab treatment at a 12-month visit, commonly observed artifacts may reduce the usefulness of OCT-A.