Choroidal thickness changes stratified by outcome in real-world treatment of diabetic macular edema

Subfoveal choroidal thickness changes after intravitreal ranibizumab injections in different patterns of diabetic macular edema using a deep learning-based auto-segmentation

PURPOSE

To evaluate the effect of intravitreal injection of ranibizumab (IVR) on subfoveal choroidal thickness (SFCT) and its relationship with central macular thickness (CMT) and best-corrected visual acuity (BCVA) changes in eyes with center-involving DME (CI-DME) using a deep learning-based auto-segmentation.

METHODS

This prospective interventional case series included 68 eyes of 68 patients with CI-DME naive to treatment. Morphological optical coherence tomography (OCT) findings of DME were classified into three patterns of structural change: (i) diffuse retinal thickening (DRT), (ii) cystoid macular edema (CME), and (iii) serous retinal detachment (SRD). All patients underwent 3+prorenata IVR. The treated eyes underwent BCVA evaluation and OCT scanning at baseline and months 1, 3, and 6 after the first injection. Then, the choroid layer was measured using a deep learning-based auto-segmentation.

RESULTS

At baseline, the mean SFCT and CMT for SRD, DRT, and CME groups were 324.68 ± 65.58 μm and 624.37 ± 77.92 μm, 348.91 ± 45.81 μm and 443.5 ± 78.33 μm, 361.4 ± 64.62 μm, and 536.5 ± 66.02 μm, respectively. After anti-VEGF treatment, the SFCT and CMT have decreased by varying degrees. At 3 and 6 months of treatment, there were no significant changes among these groups. There was no correlation between baseline SFCT and the resulting BCVA (P = 0.670, P = 0.584). There was also no correlation between changes in SFCT and BCVA, CMT (P = 0.344, P = 0.336).

CONCLUSION

After treating CI-DME with IVR, SFCT and CMT significantly decreased. However, there were no significant changes among the SRD, DRT, and CME groups.

TRIAL REGISTRATION

Trial registration: ChiCTR, ChiCTR-ROC-17013360. Registered 13 November 2017, http://www.chictr.org.cn/ChiCTR-ROC-17013360 .

Response to 1-Year Fixed-Regimen Bevacizumab Therapy in Treatment-Naïve DME Patients: Assessment by OCT Angiography

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.