Intravitreal Ranibizumab Versus Intravitreal Ranibizumab Combined with Posterior Subtenon Triamcinolone Acetonide in Diabetic Macular Edema

Abstract

Objectives: This is a retrospective, comparative evaluation of the short-term efficacy and safety of intravitreal ranibizumab (IVR) and IVR combined with posterior subtenon triamcinolone acetonide (STA) in the treatment of diabetic macular oedema (DME).

Methods: A total of 79 pseudophakic eyes of 57 patients with DME who underwent IVR injection treatment were examined retrospectively. All of the patients were treatment-naive. In the study group (STA+IVR), consisting of 30 eyes of 39 patients, the STA and IVR were administered in the first treatment session simultaneously, followed by 2 consecutive monthly IVR injections. In the control group (IVR only) comprised 40 eyes of 27 patients, 3 consecutive monthly IVR injections were administered. Patients with serous retinal detachment (SRD) according to optical coherence tomography images were identified in both groups for subgroup analyses. The primary outcome measures were changes in central macular thickness (CMT), best corrected visual acuity (BCVA), and the intraocular pressure (IOP) at 1, 2, and 3 months post-injection.

Results: There was no statistically significant difference between the demographic characteristics of the patients' baseline BCVA and CMT measurements (p>0.05). For the IVR group, the mean pre-treatment CMT and BCVA was 421.20±89.10 μm and 0.42±0.24 logMAR, respectively. After the third injection, the mean was 308.12±59.07 μm and 0.20±0.12 logMAR, respectively. The combined treatment group baseline measurements were 454.50±122.52 μm and 0.54±0.29 logMAR, respectively. After the third injection, the mean was 294.22±50.33 μm and 0.27±0.21 logMAR, respectively. The decrease was statistically significant for both groups (p=0.001). Comparison of the CMT within groups revealed a statistically significant difference in favor of the combined group after the second injection (p=0.017). There was no statistically significant difference in the BCVA gains between groups (p>0.05). Patients with SRD were evaluated as a subgroup, and at the first month, the mean gain in CMT was -71.63±57.98 μm in the control group and -123.61±93.46 μm in the study group (p=0.048). The required anti-glaucomatous treatment was statistically significant in the combined group (p=0.008).

Conclusion: Both treatments provided improvement in BCVA and CMT and can be considered functional and anatomically effective treatment options for DME.

Keywords: Diabetic macular edema; posterior subtenon triamcinolone acetonide; ranibizumab.

Figure 1.

Measurement of SMD height with calipers in an OCT section.

Figure 2.

The distribution of CMTs over time among groups.

Figure 3.

Mean CMT gain in SRD patients among groups (CMT G1: CMT gain at the 1^st month, CMT G2: CMT gain at the 2^nd month, CMT G3: CMT gain at the 3^rd month).