Double protocol therapy effectively improves visual acuity in Diabetic macular edema

Turkey: Recent research found that simultaneous double protocol therapy with Intravitreal Ranibizumab and Dexamethasone Implant Injections was effective in improving visual acuity and morphological changes for diabetic macular edema (DME) at 24 months. The study results were published in the journal Current Eye Research.  

Diabetic macular edema (DME) has a highly complex pathological process that can cause blindness in diabetic patients suffering from diabetic retinopathy. It is a consequence of diabetic retinopathy in the macular area and is secondary to retinal barrier rupture, brought about by metabolic changes of hyperglycemia. intravitreal anti-VEGF drug injections, intravitreal corticosteroid injections, focal laser photocoagulation, and vitrectomy are some of the various ways DME is treated. Mahmut Kay et al from Tinaztepe University, Izmir, Turkey conducted a study to compare the efficacy of simultaneously administered intravitreal dexamethasone implant (DEX implant) and ranibizumab (simultaneous double protocol) injections with ranibizumab monotherapy for diabetic macular edema (DME) at 24 months.

A prospective, consecutive, clinical interventional study was carried out on naïve eyes with DME. All the participants were randomized into two groups where 34 eyes received simultaneous double-protocol therapy and 34 eyes received ranibizumab monotherapy. Measuring the change in visual acuity at 24 months was the primary efficacy endpoint. The secondary efficacy endpoints were to evaluate the gain of ≥15 letters, morphological changes and central foveal thickness.

Eligibility criteria was based on the following: 

Key findings from the study: 

The mean baseline BCVA was 48 ± 23 letters in double protocol group and 52 ± 14 letters ranibizumab monotherapy group (p = 0.416).

When compared to the change from baseline at 12 months versus baseline at month 24, the mean number of ETDRS letters changed from +21.6 versus +20.2 and +9.6 versus +9.1, respectively in double protocol group and ranibizumab monotherapy group.

Nearly 65.4% of patients in double protocol group and 26.2% of patients in ranibizumab monotherapy group had gained ≥15 ETDRS letters in BCVA from baseline to 24 months (p < 0.001).

Double protocol group showed better integrity of external limiting membrane (ELM) and ellipsoid zone (EZ) when compared to ranibizumab monotherapy group at month 24.

Statistically significant increase was not found in epiretinal membrane in double protocol group at month 24, when compared with ranibizumab monotherapy group (p = 0.06 and p = 0.04 in the double protocol and ranibizumab monotherapy groups, respectively).

The mean central foveal thickness (CFT) reduced from 672 ± 293 μm to 278 ± 84 μm in double protocol group and from 631 ± 279 μm to 356 ± 108 μm in ranibizumab monotherapy group (p < 0.001 and p < 0.001) from baseline to 24 months.

Nearly 38% (13/34) of eyes in double protocol group and 18% (6/34) of eyes in ranibizumab monotherapy group had at least 5 mmHg of IOP elevation (p = 0.012) from baseline to 24 months.

From baseline to 24 months, two grades or more increased cataract density were detected 27% (6/22) of eyes in the double protocol group and in 12.5% (3/24) of eyes in the ranibizumab monotherapy group (p = 0.032). 

Thus, based on the improvements, double protocol therapy is an effective treatment option for DME with inflammatory biomarkers on OCT or/and decreased visual acuity. 

Further reading: Kaya M, Atas F, Kocak N, Ozturk T, Ayhan Z, Kaynak S. Intravitreal Ranibizumab and Dexamethasone Implant Injections as Primary Treatment of Diabetic Macular Edema: The Month 24 Results from Simultaneously Double Protocol [published online ahead of print, 2023 Jan 12]. Curr Eye Res. 2023;1-8. doi:10.1080/02713683.2023.2168013