Comparison of therapeutic effect for diabetic macular edema based on different optical coherence tomography patterns

Objective

To evaluate the efficacy of intravitreal ranibizumab (IVR) injection and/or laser photocoagulation on diabetic macular edema (DME) of different morphologic patterns based on optical coherence tomography (OCT).

Methods

A non-randomized controlled clinical trial was conducted.A total of 79 diabetic patients (108 eyes) who were diagnosed as DME in Affiliated Hospital of Nanjing University of Chinese Medicine from March 2017 to February 2018 were enrolled.The subjects were divided into diffuse macular edema (DRT) group (41 eyes), cystoid macular edema (CME) group (37 eyes) and serous retinal detachment (SRD) group (30 eyes) according to the morphological characteristics of OCT, and received intravitreal injection of 0.05 ml (0.5 mg) ranibizumab and/or laser photocoagulation according to treatment guidelines.Best corrected visual acuity (BCVA), central macular thickness (CMT) of the subjects were recorded before treatment and 1 month, 3, 6 and 12 months after treatment.The morphologic changes of macular edema and complications were recorded.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Affiliated Hospital of Nanjing University of Chinese Medicine (No.2017NL-13-03). Written informed consent was obtained from each patient before any medical examination and treatment.

Results

The 1-, 3-, 6- and 12-month post-treatment average BCVA (LogMAR) of the DRT, CME and SRD groups were improved in comparison with before treatment, and the average CMT of the three groups at various time points after treatment was reduced than that before treatment (all at P<0.05). For the 39 eyes who received IVR treatment, the 12-month post-treatment average BCVA (LogMAR) of the DRT group was 0.41±0.40, which was significantly better than 0.60±0.40 of the CME group (P=0.039). The 12-month post-treatment CMT of the DRT group was (286.05±109.56) μm, which was significantly thinner than (338.30±101.87)μm of the SRD group (P=0.045). For the 69 eyes who received IVR combined with laser photocoagulation treatment, the 6- and 12-month post-treatment average BCVA (LogMAR) of the DRT group were significantly better than those of the CME group (P=0.048, 0.043), and the average CMT at 12 months after treatment in the DRT group was (304.59±106.66)μm, which was significantly smaller than (369.34±107.80)μm in the SRD group, showing a statistical significance (P=0.041). During the follow-up, 5 eyes with SRD turned to DRT, and 3 SRD eyes turned to CME.No eye changing from DRT and CME to SRD was found.

Conclusions

Intravitreal ranibizumab injection and/or laser photocoagulation can significantly improve BCVA and reduce CMT of DME patients, and the efficacy is better in eyes with DRT than eyes with SRD or CME.

Diabetic retinopathy/therapy; Macular edema; Angiogenesis inhibitors; Monoclonal antibodies; Laser coagulation; Optical coherence tomography