Prospective Evaluation of Morphological and Functional Changes after Repeated Intravitreal Dexamethasone Implant (Ozurdex®) for Retinal Vein Occlusion

Abstract

Aims: To evaluate changes in macular morphology and function after repeated intravitreal dexamethasone implant (Ozurdex®) for macular edema (ME) due to retinal vein occlusion (RVO). Methods: Consecutive treatment-naïve patients with ME secondary to RVO were treated with Ozurdex and followed up to 12 months to evaluate functional and morphological outcomes by means of best-corrected visual acuity (BCVA) and microperimetry and by enhanced depth imaging optical coherence tomography, respectively. Results: Thirty-five eyes of 35 patients were included for the analysis (26 central RVO, 9 branch RVO). During the 12-month study period, 8 of the 35 eyes (23%) underwent 1 intravitreal dexamethasone implant, 13 of the 35 eyes (37%) underwent 2, and 14 of the 35 eyes (40%) underwent 3 intravitreal dexamethasone implants. At 1 month from the 1st intravitreal dexamethasone implant, the mean BCVA, retinal sensitivity and central macular thickness (CMT) significantly improved compared to the baseline values. At 3 months, the mean BCVA improvement was no more significant, while retinal sensitivity further improved and CMT slightly worsened, remaining, however, significantly better than at baseline. At 12 months, those eyes that had undergone 2 retreatments showed a significant improvement of the mean BCVA, mean retinal sensitivity and CMT compared to the baseline values [0.61 ± 0.29 logarithm of the minimum angle of resolution (LogMAR) vs. 0.82 ± 0.33 LogMAR, p = 0.011; 12.94 ± 4.73 dB vs. 10.75 ± 3.27 dB, p = 0.043, and 321 ± 91 µm vs. 735 ± 169 µm, p = 0.001, respectively]. In those eyes that had undergone only 1 retreatment, a significant improvement was recorded only for the CMT (500 ± 224 µm vs. 695 ± 302 µm, p = 0.044). The mean retreatment interval between the 1st and the 2nd injection was 4.5 ± 1.1 months (range 3-7 months), and between the 2nd and the 3rd injection it was 4.1 ± 1 months (range 3-6 months). Conclusions: In eyes with ME secondary to RVO, Ozurdex produces functional benefits as early as 1 month after treatment/retreatment. Current optical coherence tomography and microperimetry findings confirm the concept that, in most cases, the optimum retreatment interval should be <6 months from the 1st injection.

Dexamethasone intravitreal implant in retinal vein occlusion: real-life data from a prospective, multicenter clinical trial

“…For patients who received a second implant in this study, the mean time between the first and second implant was 155 days (approximately 5 months). This interval is consistent with the interinjection interval of 4.5 months reported in a prospective evaluation of DEX implant in patients with treatment-naïve RVO [21], and with the interinjection interval of 5.6 months reported in the SHASTA study, a large retrospective evaluation in patients with BRVO and CRVO who received at least two DEX implant injections [9]. The mean interval between DEX implant treatments was approximately 5 months (151 days) for patients in the SHASTA study who received no other treatment for RVO-associated ME during the study period [22].…”

Treatment patterns of ranibizumab intravitreal injection and dexamethasone intravitreal implant for retinal vein occlusion in the USA

“…28 Similarly, a recent prospective study of 35 patients indicated that the optimal time for re-treatment for most patients with ME secondary to RVO is <6 months after the first dexamethasone treatment. 29 …”

Comparison of ranibizumab versus dexamethasone for macular oedema following retinal vein occlusion: 1‐year results of the COMRADE extension study

“…In addition, we observed greater fluctuation of mean CSRT in DEX-treated patients than in conjunction with ranibizumab over the entire study period. Previous studies have demonstrated that this factor is a typical feature of repeat DEX treatment in patients with RVO (Bandello et al 2015). However, while BRVO patients who underwent continued treatment with ranibizumab exhibited significantly better outcomes compared to DEX, this difference was no longer statistically significant by the end of the extension trial among patients with CRVO.…”

“…Previous studies have demonstrated that this factor is a typical feature of repeat DEX treatment in patients with RVO (Bandello et al 2015). Patients who received continued treatment with ranibizumab after completing the core study period (COMRADE-B, COMRADE-C) exhibited a sustained improvement in BCVA until month 12, whereas in the DEX-treated patients who entered the extension trial at a lower BCVA level, mean BCVA improved during the first 2 months after retreatment with DEX, but declined thereafter.…”