Long-term efficacy and duration of action of dexamethasone implant, in vitrectomised and non-vitrectomised eyes with persistent diabetic macular oedema

Safety and Efficacy of Dexamethasone Intravitreal Implant Given Either First-Line or Second-Line in Diabetic Macular Edema

Diabetic macular edema (DME) is a common sight-threatening complication of diabetic retinopathy (DR) and the leading cause of severe visual impairment among the working-age population. Several therapeutic options are available for the management of DME, including intravitreal corticosteroids. They have been traditionally used as second-line treatment, due to the risk of intraocular pressure increase and cataract-related adverse events. However, attention has recently been focused on the primary or early use of intravitreal corticosteroids, due to growing evidence of the crucial role of inflammation in the pathogenesis of DME. Furthermore, intravitreal steroid implants offer the additional advantage of a longer duration of action compared to anti-vascular endothelial growth factor agents (anti-VEGF). This review aims to summarize the available evidence on the efficacy and safety profile of dexamethasone (DEX) intravitreal implant, with a specific focus on clinical scenarios in which it might be considered or even preferred as first-line treatment option by adequate selection of patients, considering both advantages and possible adverse events. Patients with contraindications to anti-VEGF, DME with high inflammatory OCT biomarkers, pseudophakic patients and phakic patients' candidates to cataract surgery as well as vitrectomized eyes may all benefit from first-line DEX implant. Additionally, DME not responders to anti-VEGF should be considered for a switch to DEX implant and a combination therapy of DEX implant and anti-VEGF could be a valid option in severe and persistent DME.

Vitrectomized vs non-vitrectomized eyes in DEX implant treatment for DMO-Is there any difference? the VITDEX study

OBJECTIVE

We aimed to compare visual and anatomical outcome in vitrectomized and non-vitrectomized eyes treated with dexamethasone (DEX) implant due to diabetic macular oedema (DMO).

DESIGN

Multicenter, retrospective, interventional study.

PARTICIPANTS

236 eyes from 234 patients with DMO with or without previous vitrectomy performed with follow-up of 12 months.

METHODS

Records were reviewed for cases of DMO treated with DEX implant in vitrectomized and not vitrectomized eyes. Best corrected visual acuity (BCVA), central subfoveal thickness (CST), and intraocular pressure (IOP) were recorded at baseline and 12 months after treatment with DEX implants. Correlations between vitreous status and visual and anatomical outcome, as well as safety profile were analysed.

MAIN OUTCOME MEASURES

BCVA and CST over follow-up period.

SECONDARY OUTCOMES

cataract rate formation, intraocular pressure increase, number of implants needed.

RESULTS

The non-vitrectomized group included 130 eyes (55.1%), the vitrectomized group included 106 eyes (44.9%). The groups were well balanced for age and gender (p = 0.540, and p = 0.053, respectively). Both groups showed statistically significant improvement in BCVA and CST (for all groups: p < 0.001). There was no significant difference between the groups in terms of change in vision (p = 0.89) and anatomy (p = 0.65). The mean number of DEX implants given during follow-up was 3.5 in both groups, and there was no significant difference between the groups (p = 0.81).

CONCLUSION

We demonstrated similar anatomical and functional efficacy of DEX implant in non-vitrectomized and vitrectomized eyes. Its efficacy was not influenced by full vitrectomy for diabetic retinopathy complications. Safety profile was well balanced between groups.

Efficacy and safety of the dexamethasone implant in vitrectomized and nonvitrectomized eyes with diabetic macular edema: A systematic review and meta-analysis

Purpose: To compare the efficacy and safety of the intravitreal dexamethasone (DEX) implant for the treatment of diabetic macular edema (DME) in vitrectomized and nonvitrectomized eyes.

Methods: We performed a literature search in four electronic databases (PubMed, EMBASE, MEDLINE, and Cochrane Library) from inception to 22 May 2022. Studies comparing the efficacy of the DEX implant in vitrectomized and nonvitrectomized eyes with DME with at least 3 months of follow-up were included. The main outcomes included comparison of the mean change in the best-corrected visual acuity (BCVA) and central macular thickness (CMT) from baseline to different follow-up endpoints between the vitrectomized and nonvitrectomized groups. The secondary outcomes were the mean duration of action for the first DEX implantation and the number of required injections throughout the follow-up period. Safety data were collected and compared.

Results: The final analysis included 7 studies involving 582 eyes, 208 vitrectomized eyes and 374 nonvitrectomized eyes. The mean between-group differences in BCVA improvement were not significant at any endpoint, with averages difference of −0.07 logarithm of the minimum angle of resolution (logMAR) (p = 0.088) at 1 month, −0.03 logMAR (p = 0.472) 3 months, −0.07 logMAR (p = 0.066) 6 months, and −0.04 logMAR (p = 0.486) 12 months. The mean between-group differences in CMT reduction were not statistically significant, with mean differences of 7.17 μm (p = 0.685) at 1 month, 20.03 μm (p = 0.632) 3 months, −1.80 μm (p = 0.935) 6 months, and −25.65 μm (p = 0.542) 12 months. However, the vitrectomized group had a significantly shorter duration of action during the first DEX implantation than the nonvitrectomized group, with a mean difference of 0.8 months (p = 0.005). No significant between-group differences were detected for the number of required injections or safety profile.

Conclusion: This meta-analysis showed similar efficacy and safety of the sustained-release DEX intravitreal implant for vitrectomized and nonvitrectomized eyes with DME. The intravitreal DEX implant could be considered an effective choice for DME treatment in eyes with prior vitrectomy.

The effect of pars plana vitrectomy with internal limiting membrane peeling on the durability of the intravitreal dexamethasone implant in the treatment of diabetic macular edema

Purpose

To evaluate the influence of pars plana vitrectomy with internal limiting membrane peeling on recurrence time of diabetic macular edema in eyes under treatment with dexamethasone intravitreal implant injections.

Material and methods

Twelve pseudophakic eyes of 12 patients with non-proliferative diabetic retinopathy and non-tractional diabetic macular edema were included. All eyes had already been treated with two or more dexamethasone intravitreal implant injections evidencing a recurrence time of three months or less (early recurrence). At baseline, they underwent pars plana vitrectomy with internal limiting membrane peeling, ending with dexamethasone intravitreal implant injection. Patients were then followed-up monthly, treated with a second injection at the first recurrence, and followed up to the second recurrence. Measurements of best corrected visual acuity, intraocular pressure, and central foveal thickness by spectral-domain optical coherence tomography were performed at each follow-up examination.

Results

Vitrectomized eyes showed a significant extension of recurrence time of diabetic macular edema, and specifically from 3.4 (3.2–3.7) to 6.5 (5.7–8.2) months after the first injection, and to 7.0 (5.7–8.2) months (p < 0.01) after the second injection (p < 0.01).

Conclusions and importance

Pars plana vitrectomy with internal limiting membrane peeling seems not to influence functional and anatomical results in eyes under treatment with dexamethasone intravitreal implant injections for diabetic macular edema, but appears to significantly extend the benefit of the drug.

CLINICAL FEATURES OF INTRAVITREAL DEXAMETHASONE IMPLANTATION IN VITRECTOMIZED EYES OF PATIENTS WITH DIABETIC MACULAR EDEMA

PURPOSE

To identify the clinical outcomes of intravitreal dexamethasone implantation (IVD) in previously vitrectomized eyes of patients with diabetic macular edema.

METHOD

We performed a retrospective observational study. We recorded central subfield thickness, best-corrected visual acuity, and intraocular pressure up to 12 months after IVD implant placement. We compared the duration of IVD action, intraocular pressure trends, and the prevalence of ocular hypertension after the first IVD treatment of nonvitrectomized and vitrectomized eyes. We also compared the central subfield thickness, best-corrected visual acuity, number of IVD treatments, and prevalence of ocular hypertension between the 2 groups after 12 months.

RESULTS

We found no significant between-group differences in the central subfield thickness, best-corrected visual acuity, or the prevalence of ocular hypertension during treatment. However, the duration of action of the first IVD treatment was significantly shorter in vitrectomized eyes, and these eyes required more IVD treatments during the 12-month follow-up period. The maximal average intraocular pressure was observed at 2 months after the first IVD treatment in the nonvitrectomized group, but 1 month after the first IVD treatment in the vitrectomized group.

CONCLUSION

These findings suggest that the IVD pharmacokinetics and pharmacodynamics differ between vitrectomized and nonvitrectomized eyes. Nevertheless, given the relatively long-lasting effectiveness of the treatment and the good clinical results, consecutive IVD treatments may be beneficial for patients with diabetic macular edema with previously vitrectomized eyes.

Comparison of Intravitreal Dexamethasone Implant and Ranibizumab in Vitrectomized Eyes with Diabetic Macular Edema

Purpose

This retrospective study aimed to compare the efficacy of intravitreal ranibizumab (IVR) and intravitreal dexamethasone implant (IDI) for pseudophakic vitrectomized eyes with diabetic macular edema (DME) in a single institution.

Methods

Pseudophakic vitrectomized eyes with treatment-naïve center-involved DME were enrolled, with one eye in each patient. They were divided into two groups: one group receiving IDI every 3 to 4 months and another group receiving IVR using 3 monthly plus treat-and-extend injections, all with monthly follow-up for 6 months. Switch of intravitreal drugs or deferred macular laser was not allowed. Primary outcome measures included change in central foveal thickness (CFT) in 1 mm by spectral-domain optical coherence tomography and best-corrected visual acuity (BCVA) at Month 6.

Results

Twenty-two eyes were included in the IDI group and 26 eyes in the IVR group. The baseline demographics, glycosylated hemoglobin level, intraocular pressure (IOP), BCVA, and CFT did not significantly differ (p > 0.05). Compared to baseline data, CFT decreased and BCVA improved significantly after either IDI or IVR at Month 6 (p < 0.05). Significantly better mean final BCVA (0.38 logMAR vs. 0.62 logMAR, p=0.04), more mean visual gain (−0.30 logMAR vs. −0.15 logMAR, p=0.02), lower mean final CFT (310.9 μm vs. 384.2 μm, p=0.04), and larger mean CFT decrease (−150.0 μm vs. −60.1 μm, p=0.03) were found in the IDI group compared to those in the IVR group. A smaller mean treatment number (2.6 vs. 5.6, p < 0.001) and higher rate of postinjection ocular hypertension requiring topical hypotensive agent therapy (27.3% vs. 0%, p=0.0002) were demonstrated in the IDI group than those in the IVR group.

Conclusion

We concluded that IDI and IVR can both effectively treat vitrectomized eyes with DME. Dexamethasone implants had significantly better visual/anatomical improvement, smaller treatment number, and higher rate of elevated IOP after injection than IVR in pseudophakic vitrectomized eyes with DME in a 6-month period.

The prognostic role of optical coherence tomography in diabetic macular edema patients undergoing early dexamethasone implant shift

PURPOSE

To determine the prognostic characteristics of optical coherence tomography (OCT) parameters by evaluating diabetic macular edema (DME) patients with early dexamethasone (DEX) shift after three doses of intravitreal ranibizumab (RNB) injection.

METHODS

Fifty-four eyes of 34 patients who had DEX implant after three doses of RNB were included in this retrospective study. Early DEX shift includes patients who received direct DEX implant replacement after three doses of RNB load. Baseline OCT values and factors affecting best corrected visual acuity (BCVA) and central macular thickness (CMT) response were analyzed with logistic regression analyses.

RESULTS

The presence of subretinal fluid and hyperreflective spot (HRS) >20 were found to be a negative predictive factor for anatomical response. (p = 0.009, p = 0.001, respectively) Low initial BCVA creates a positive effect on visual gain.( p = 0.041) Giant outer nuclear layer cysts, completely disrupted inner segment-outer segment and HRS > 20 have a negative effect on visual gain. (p = 0.025, p = 0.043, p = 0.023, respectively) According to the receiver operating characteristic analysis, the subretinal fluid volume threshold at which >20% reduction in CMT occurs was determined to be 0.85 mm³. (sensitivity 70%, specificity 84% area under the curve 0.817, p = 0.021).

CONCLUSION

The presence of high number of HRS and high subretinal fluid volume at the baseline negatively affect prognosis even in patient groups with early DEX shift.

Initial Ten Years of Experience with the Intravitreal Dexamethasone Implant: A Retrospective Chart Review

Purpose

To evaluate the initial ten years of results from the intravitreal dexamethasone implant (DEX) in patients treated for retinal vein occlusion (RVO), diabetic macular edema (DME) or uveitis.

Methods

Retrospective chart review of patients receiving DEX since its FDA approval. Best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography, intraocular pressure and cataract status were collected. Baseline data were collected from the initial DEX and post-treatment data at the visit at least four weeks after the last DEX.

Results

In total, 315 eyes received 1216 DEX over 63.9±4.6 weeks. In the branch RVO (n=90), central RVO (n=59) and DME (n=62) cohorts, BCVA improved significantly (p<0.05). The uveitis (n=154) cohort did not have a significant change in BCVA, 0.62±0.04 to 0.61±0.04 logMAR (p=0.34). Younger patients, vitrectomized eyes, and eyes without a history of glaucoma were associated with significantly better BCVA outcomes in the uveitis cohort (p<0.05). Overall, CMT decreased significantly from 376.6±6.8 to 322.7±5.0 µm (p<0.05). Intraocular pressure increased significantly (p<0.001) and the percentage of patients requiring anti-glaucoma medications increased from 33.0% to 67.6%. Of phakic eyes, 58.8% (n=63) had cataract progression or underwent surgery with those who underwent surgery experiencing a significant improvement in BCVA (p<0.05).

Conclusion

Repeated DEX over extended follow-up offers significant anatomic benefits to all cohorts. Visual benefits are only seen in RVO, DME and select uveitis demographics.

Effect of dexamethasone intravitreal implant in vitrectomized and nonvitrectomized eyes of Taiwanese patients with treatment-naïve diabetic macular edema

BACKGROUND/PURPOSE

Vitrectomy may affect intravitreal drug clearance and efficacy for treating diabetic macular edema (DME). This study aimed to evaluate functional and anatomical outcomes of intravitreal dexamethasone (DEX) implant for vitrectomized and nonvitrectomized eyes with treatment-naïve DME in Taiwanese patients.

METHODS

In this retrospective single-center study, we reviewed treatment-naïve patients who received DEX implant monotherapy for center-involved DME from January 2015 to May 2017. Retreatments were provided at least 4 months apart as needed. The primary outcomes included changes from baseline in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) at Month 6. Adverse events were recorded.

RESULTS

Twenty-seven eyes in 27 patients had prior vitrectomy and 43 eyes in 41 patients without vitrectomy. Baseline data were comparable. Overall, the improvements in BCVA and CFT were significant by 1 month post-treatment and sustained throughout the study (all p < 0.05). At Month 6, BCVA improved by 16.5 and 12.1 letters, and CFT reduced by 138.0 and 121.9 μm in vitrectomized and nonvitrectomized eyes, respectively, with a mean of 1.5 DEX implant injection. No significant differences in clinical outcomes were seen between the two groups (all p > 0.05). DEX implant injection was well tolerated. About 30% of patients had post-injection intraocular pressure value > 20 mmHg, and all were manageable with topical hypotensive agents, and no serious ocular complication was observed.

CONCLUSION

In this 6-month retrospective study, intravitreal DEX implant was effective in Taiwanese patients with treatment-naïve DME regardless of vitrectomy status.

Effectiveness of Intravitreal Dexamethasone Implant Treatment for Diabetic Macular Edema in Vitrectomized Eyes

Objectives:

To report the effectiveness and long-term outcomes of intravitreal dexamethasone implantation for diabetic macular edema (DME) in vitrectomized eyes

Materials and Methods:

Medical records of patients were retrospectively reviewed. Time of pars plana vitrectomy (PPV), PPV indications, interval between DEX injection and PPV, other intravitreal treatment prior to DEX application, best corrected visual acuity (BCVA), intraocular pressure (IOP), and central retinal thickness (CRT) measured by optical coherence tomography were recorded.

Results:

Seventeen eyes of 17 patients were included in the study. The mean follow-up after DEX injection was 21±2.4 months (12-43 months). The female/male ratio was 11/6. Mean age was 60.7 years (46-70 years). Sixteen eyes (94.1%) were pseudophakic at the time of DEX treatment. The most common indication for PPV was tractional retinal detachment (8 eyes, 47.1%). Ten eyes (58.8%) received a single injection and a total of 30 DEX implantations were performed. Mean BCVA was 0.77 logarithm of the minimum angle of resolution (logMAR) units before the first injection and improved to 0.64, 0.68 and 0.66 logMAR after 1, 3 and 6 months, respectively (p<0.01). CRT decreased significantly from 452 µm at baseline to 310, 368±34 and 375 µm after 1, 3 and 6 months, respectively (p<0.04). Mean IOP was 16±1.2 mmHg at baseline and 18.2, 18.8 and 18.5 mmHg after 1, 3, and 6 months (p>0.05). Two eyes (%8) received topical anti-glaucoma medication (IOP≥25 mmHg). Similar results were observed in eyes receiving repeated DEX injections.

Conclusion:

Intravitreal DEX injection treatment seems to be effective for improving BCVA and decreasing CRT in vitrectomized eyes with DME. This effect seemed to last for 6 months in most eyes, but maximized at 3 months. Patients with repeated injections often require injection before 6 months.