Morphology and Function over a One-Year Follow Up Period after Intravitreal Dexamethasone Implant (Ozurdex) in Patients with Diabetic Macular Edema

Formulation Advances in Posterior Segment Ocular Drug Delivery

Posterior segment ocular diseases, such as diabetic retinopathy, age-related macular degeneration, and retinal vein occlusion, are leading causes of vision impairment and blindness worldwide. Effective management of these conditions remains a formidable challenge due to the unique anatomical and physiological barriers of the eye, including the blood-retinal barrier and rapid drug clearance mechanisms. To address these hurdles, nanostructured drug delivery systems are proposed to overcome ocular barriers, target the retina, and enhance permeation while ensuring controlled release. Traditional therapeutic approaches, such as intravitreal injections, pose significant drawbacks, including patient discomfort, poor compliance, and potential complications. Therefore, understanding the physiology and clearance mechanism of eye could aid in the design of novel formulations that could be noninvasive and deliver drugs to reach the target site is pivotal for effective treatment strategies. This review focuses on recent advances in formulation strategies for posterior segment ocular drug delivery, highlighting their potential to overcome these limitations. Furthermore, the potential of nanocarrier systems such as in-situ gel, niosomes, hydrogels, dendrimers, liposomes, nanoparticles, and nanoemulsions for drug delivery more effectively and selectively is explored, and supplemented with illustrative examples, figures, and tables. This review aims to provide insights into the current state of posterior segment drug delivery, emphasizing the need for interdisciplinary approaches to develop patient-centric, minimally invasive, and effective therapeutic solutions.

Does microperimetry have a role in monitoring visual function in patients with Behçet uveitis?

BACKGROUND

To evaluate the change in time in visual acuity, central macular thickness (CMT), and microperimetry (MP) findings in Behçet uveitis (BU) patients who were in remission with maintenance therapy.

METHODS

This single center, retrospective, observational cohort study included twenty-five eyes of 25 patients with BU who were in remission during maintenance therapy. Best corrected visual acuity (BCVA), CMT, macular integrity index, average threshold, and fixation stabilities (P1 and P2) evaluated at six-month intervals were recorded. The changes in time were statistically analyzed. Paired samples t-test was used for normally distributed data and Wilcoxon rank test was performed for non-normally distributed data.

RESULTS

The mean BCVA and CMT showed no significant changes after six months. Although the mean macular integrity index decreased and the mean fixation stabilities increased after six months, these findings were not statistically significant. The mean average threshold was 16.8 dB at baseline and it increased significantly to 19.3 dB in the sixth month (p < 0.001).

CONCLUSIONS

The results of our study suggest that although visual acuity and CMT showed no change in patients with Behçet uveitis receiving maintenance therapy, MP could detect an improvement in macular function.

Effects of Dexamethasone Intravitreal Implant on Multifocal Electroretinography in Diabetic Macular Oedema

PURPOSE

To evaluate the efficacy of the dexamethasone implant on the electrophysiological profile of Diabetic Macular Oedema (DMO) patients over six months.

METHODS

In this prospective, single-center study 30 eyes of 22 patients were examined using comprehensive baseline assessments including best-corrected visual acuity (BCVA), central retinal thickness (CRT), contrast sensitivity (CS) and multifocal electroretinogram (mfERG), before and after 0.7mg dexamethasone implant injection, with follow-ups at months 1, 2, 4, and 6. The study employed mixed models to analyse within-subject and between-subject correlations, considering the complexities of multiple measurements per subject.

RESULTS

At baseline, BCVA was 0.66 ± 0.104 logMAR, improving to 0.568 ± 0.104 logMAR by month 6 (P > 0.05). CRT significantly reduced from 521 ± 28.7 μm to 336 ± 28.7 μm (P < 0.05). CS slightly increased from 26.8 ± 1.23 letters to 28.5 ± 1.05 letters (P > 0.05). P wave amplitude saw a notable rise from 33.4 ± 5.66 μV to 47.9 ± 5.43 μV (P < 0.05). P wave implicit time changed minimally from 47.4 ± 0.503 seconds to 48.0 ± 0.503 seconds (P > 0.05). No severe adverse events were recorded.

CONCLUSION

These results underscore the 0.7mg dexamethasone implant's potential in improving certain electrophysiological markers in DMO, while also highlighting the need for further investigation into its comprehensive impact on retinal function.

Effectiveness of Suprachoroidal Injection of Triamcinolone Acetonide in Diabetic Macular Edema Following Pars Plana Vitrectomy Using a Modified Custom Microneedle

Purpose

The present study evaluated the efficacy of suprachoroidal injection of Triamcinolone Acetonide (SCTA) in diabetic macular edema (DME) following pars plana vitrectomy (PPV) using a modified microneedle.

Patients and methods

A prospective interventional study was conducted on 60 eyes of 60 patients with centrally involved diabetic macular edema following pars plana vitrectomy (PPV). SCTA was performed at the baseline and repeated after 3 months in case of persistent subretinal or intraretinal fluid, central macular thickness (CMT) more than 300 µm or visual loss by more than one line of the Snellen chart.

Results

The present study detected significant reduction of the CMT from 498.3 ± 94.8 µm at the baseline to 212.3 ± 11.9 µm after 12 months of injection with p < 0.001 and a significant improvement of best corrected visual acuity (BCVA) from 1 (0.9-1.2) at the baseline to 0.5 (0.3-0.7) after 12 months of injection with p < 0.001. The intraocular pressure (IOP) increased significantly after 3 months of injection with p < 0.001 and then gradually declined to its normal level after 6 months. Inner segment/outer segment (IS/OS) disruption was the only significant predictor of the final CMT; however, the number of injections, IS/OS disruption, baseline BCVA and the HbA1C level were the significant predictors of the final BCVA after injection.

Conclusion

Suprachoroidal injection of TA using this microneedle resulted in significant anatomical and functional improvement in previously vitrectomized diabetic macular edema patients with no recorded ocular or systemic adverse events.

DEXAMETHASONE IMPLANT VERSUS TOPICAL CARBONIC ANHYDRASE INHIBITORS IN PATIENTS WITH BILATERAL RETINITIS PIGMENTOSA-RELATED CYSTOID MACULAR EDEMA: A Prospective, Paired-Eye Pilot Study

PURPOSE

To compare within-subject efficacy and safety of intravitreal dexamethasone implant and topical carbonic anhydrase inhibitors in the treatment of retinitis pigmentosa-related cystoid macular edema.

METHODS

Patients with bilateral retinitis pigmentosa-related cystoid macular edema were treated with intravitreal dexamethasone implant in one eye and topical carbonic anhydrase inhibitors in the contralateral eye. The primary endpoint was a change in central macular thickness. Secondary endpoints were changes in best-corrected visual acuity and microperimetric central retinal sensitivity. Intraocular pressure and other ocular complications were evaluated for safety assessment.

RESULTS

Nine patients were recruited for this 12-month follow-up study. Central macular thickness was significantly lower in intravitreal dexamethasone implant-treated eyes than in topical carbonic anhydrase inhibitors-treated eyes at Months 1 and 7, whereas mean best-corrected visual acuity was better in eyes treated with topical carbonic anhydrase inhibitors at Month 12 (borderline significant P = 0.0510). There was no difference in microperimetric sensitivity between the two treatments. Three patients developed ocular hypertension after intravitreal dexamethasone implant. Intravitreal dexamethasone implant showed an effect on the contralateral eye in five of nine patients.

CONCLUSION

Intravitreal dexamethasone implant was more effective than topical carbonic anhydrase inhibitors in reducing retinitis pigmentosa-related cystoid macular edema 1 month after treatment. Corticosteroids can play a key role in the management of retinitis pigmentosa-related cystoid macular edema; however, their routes, timing, and modes of administration should be further explored.

Healthcare expenditure of intravitreal anti-vascular endothelial growth factor inhibitors compared with dexamethasone implant for diabetic macular oedema

PURPOSE

The aim of this study was to estimate the 1-year costs associated with treating diabetic macular oedema (DME) patients using current intravitreal anti-vascular endothelial growth factor (anti-VEGF) biologics compared with the dexamethasone implant.

METHODS

We conducted a descriptive cost-evaluation analysis using data from Oslo University Hospital and literature to compare three different intravitreal drugs for DME: bevacizumab, aflibercept and dexamethasone. Stratification of patients into 'Naive' or 'Switch' group was based on treatment history. We estimated the costs from healthcare and 'extended' healthcare perspectives. Sensitivity analysis evaluated the impact of various parameters.

RESULTS

The average injections per patient per year for the Naive group (bevacizumab), Switch group (aflibercept) and dexamethasone were 9.5, 9.1 and 3.0 respectively. From a healthcare perspective, the 1-year costs for the Naive group were 15% lower (bevacizumab, €3619), and for the Switch group, 23% higher (aflibercept, €5226) compared with dexamethasone (€4252). The 'extended' healthcare perspective showed the cost per patient per year for bevacizumab remained nominally lower in the Naive group, while dexamethasone remained lower for the Switch group (€5116 for dexamethasone, compared to €4987 for bevacizumab and €6537 for aflibercept).

CONCLUSIONS

From a primary healthcare perspective, the dexamethasone as a first-line DME treatment may increase economic costs in settings where bevacizumab is used off-label. Treating resistant DMEwith dexamethasone may reduce the costs and treatment burden compared with switching to aflibercept.

Dexamethasone Intravitreal Implant for the Treatment of Macular Edema and Uveitis: A Comprehensive Narrative Review

Purpose

The purpose of this review article is to provide a comprehensive review of the current applications of intravitreal DEX implant (Ozurdex^®, Allergan Inc, Irvine, CA) for a variety of ophthalmic conditions – ranging from FDA approved indications to off-label uses. We have attempted to provide relevant evidence from the literature to help a reader develop an understanding of the biological and pharmacokinetic properties of DEX implant, its uses, and potential side effects.

Methods

PubMed searches were performed using the terms “Ozurdex”, or “intravitreal DEX implant”, AND “retinal vein occlusion”, or “diabetic macular edema”, or “uveitis”. The search was performed in July of 2021, with an additional search in October 2021. All original English language articles were considered for this review.

Results

DEX implant has evidence of efficacy in a variety of clinical situations including macular edema associated with retinal vein occlusion, diabetes, uveitis, and others. Safety concerns include cataract formation and progression, intraocular pressure elevation, complications related to intravitreal injection, and opportunistic infections secondary to steroid-induced immune suppression.

Conclusion

DEX implant is a useful tool in the management of several retinal disorders. Further studies are needed for head-to-head comparison with other treatment modalities and to determine its precise place in clinical practice.

Assessment of Reinjection Numbers and Intervals for Diabetic Macular Edema Patients Who Received Dexamethasone Intravitreal Implants in Germany and Switzerland

PURPOSE

The purpose was to assess the number and intervals of dexamethasone intravitreal implant (DEX) reinjections in a real-world setting for the treatment of diabetic macular edema (DME) and to determine the relationship with effectiveness and safety.

PATIENTS AND METHODS

Data were abstracted from medical records of DME patients in Germany and Switzerland for this retrospective, multicenter, drug utilization study. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) changes 7-12 weeks post-injection(s) measured effectiveness. Adverse events (AEs) of special interest were reported.

RESULTS

A total of 141 patients, 108 from Germany and 33 from Switzerland, were assessed. Mean (SD) reinjection interval was 5.7 (4.2) months. Mean baseline BCVA was 61.6 letters, and mean baseline CRT was 413.3 µm. The mean BCVA and CRT changes at 7-12 weeks after baseline, reinjection 1, 2, and 3 were +3.4, +3.7, +3.2, and -1.4 letters and -88.3, -81.6, -102.4, and -124.1 μm, respectively. The Spearman correlation between change in BCVA and CRT and DEX reinjection interval was r=0.03 (P=0.66) and r=0.07 (P=0.38), respectively. Only 18% of patients experienced at least 1 AE.

CONCLUSION

There was no statistically significant correlation between drug effectiveness and reinjection intervals in either country. Although these results are preliminary, they indicate that DEX improves BCVA and CRT in real-world clinical practice.

Intravitreal injection associated rhegmatogenous retinal detachment: outcomes of a European analysis

Purpose

As the number of intravitreal injections (IVI) increases annually, this study aimed to assess the anatomical and functional outcomes following rhegmatogenous retinal detachment (RRD) surgery for IVI-associated RRD (IVARD).

Methods

All non-vitrectomized eyes developing IVARD since 2007 in two European vitreoretinal centers (Department of Ophthalmology, LMU Munich, Germany, and Eye Clinic Luigi Sacco, University of Milan, Milan, Italy) were included. Main outcomes were primary and secondary retinal attachment rate after surgery, rate of proliferative vitreoretinopathy (PVR), and final functional result. Ten years of incidence rates per injection were calculated for one center.

Results

Fifty-two eyes of 52 patients comprised the study. Primary anatomic success rate was 83% (n = 43) and secondary 96% (n = 50). PVR was observed in all uveitic eyes (n = 3), in eyes with postoperative cystoid macular edema (n = 2), and in 8 of 9 eyes that received the dexamethasone implant (DEX). Age, number of prior injections, duration of symptoms, or time between last IVI and RRD did not show any statistically significant differences with regard to presence of PVR or not. Mean BCVA improved in 28 cases, remained stable in 16 cases, and worsened in 8 cases. The RRD incidence rate was statistically significant higher for DEX and ocriplasmin compared with that for anti-VEGF agents.

Conclusion

The anatomical result after one surgical intervention seems acceptable, but the final visual outcome remains rather poor, because of the underlying macular disease. In our population, injection with DEX is associated with higher IVARD rate, presence and development of PVR, and recurrent RRD in comparison with anti-VEGF agents.

Recent trends in drug-delivery systems for the treatment of diabetic retinopathy and associated fibrosis

Diabetic retinopathy is a frequent microvascular complication of diabetes and a major cause of visual impairment. In advanced stages, the abnormal neovascularization can lead to fibrosis and subsequent tractional retinal detachment and blindness. The low bioavailability of the drugs at the target site imposed by the anatomic and physiologic barriers within the eye, requires long term treatments with frequent injections that often compromise patient's compliance and increase the risk of developing more complications. In recent years, much effort has been put towards the development of new drug delivery platforms aiming to enhance their permeation, to prolong their retention time at the target site and to provide a sustained release with reduced toxicity and improved efficacy. This review provides an overview of the etiology and pathophysiology of diabetic retinopathy and current treatments. It addresses the specific challenges associated to the different ocular delivery routes and provides a critical review of the most recent developments made in the drug delivery field.

Impacts of intravitreal anti-VEGF therapy on retinal anatomy and neurophysiology in diabetic macular edema

PURPOSE

To evaluate anatomical and neuroretinal functional aspects in patients with diabetic macular edema (DME) after intravitreal anti-vascular endothelial growth factor (VEGF) therapy, in particular aflibercept.

MATERIALS AND METHODS

This prospective single-centered interventional study was performed at Afyonkarahisar Health Science University Faculty of Medicine, Department of Ophthalmology, where 32 eyes of 32 patients with DME were investigated. All patients received five intravitreal aflibercept injections on a monthly basis and were followed up for ≥ 6 months. After a comprehensive ophthalmological examination, including the measurements of visual acuity and intraocular pressure, and an antero-posterior segment slit-lamp biomicroscopy before and after full pupil dilation, fundus fluorescein angiography and optical coherence tomography were performed at baseline and during the third and sixth months post-therapy. Microperimetry and multifocal electroretinography were also performed at baseline and during the sixth months.

RESULTS

Mean visual acuity increased from 0.73 to 0.57 and 0.33 logarithm of the minimum angle of resolution (logMAR) during the third and sixth months, respectively (p < 0.001). Changes in intraocular pressure were not statistically significant (p = 0.472). There was statistically significantly decreased mean central macular thickness from 390.2 μm to 242.6 and 289.7 μm during the third and sixth months, respectively (p < 0.001). Significantly improved fixation patterns during the sixth month, along with significantly increased macular sensitivity from 8.2 to 14.2 dB (p < 0.001) and significantly decreased local deficit from - 10.3 to 5.5 dB (p < 0.001) were observed. Further, there was a significantly increased N1 amplitude in the first ring and significantly increased P1 amplitude in all rings (p for each parameter < 0.05). There was also significantly decreased N1 wave implicit time in all rings and significantly decreased P1 wave in the second, third, fourth and fifth rings (p for each parameter < 0.05).

CONCLUSIONS

Patients with DME showed profound improvement in the retinal neurophysiological function, which was also accompanied by anatomical and ultrastructural integrity recovery after intravitreal aflibercept therapy. In the pathogenesis of DME, the influence of neurodegeneration has been increasingly gaining significant attention. Consequently, the need to assess neurophysiological effects of anti-VEGF therapy using a variety of diagnostic measures like electrophysiological studies and multimodal imaging technologies is undeniably growing.

Efficacy of Intravitreal Dexamethasone Implant in Different Patterns of Diabetic Macular Edema

PURPOSE

Different patterns of diabetic macular edema (DME) suggest different pathogenesis and drug response. We evaluated the outcomes after intravitreal dexamethasone (DEX) implant for DME with or without serous retinal detachment (SRD).

METHODS

In this retrospective study, 22 naïve patients (23 eyes) with DME who underwent a single DEX implant were evaluated. Based on the optical coherence tomographic pattern of DME, 12 eyes had a cystoid macular edema pattern (Group 1) and 11 eyes had an SRD pattern (Group 2). The best-corrected visual acuity (BCVA), central retinal thickness (СRТ), central retinal volume (CRV), SRD height (SRDh), and intraocular pressure (IOP) were recorded before and at two and four months after the treatment.

RESULTS

There were no significant differences between the groups regarding demographic, clinical data and outcomes at baseline. In Group 1, the CRT and CRV significantly decreased at two months (P = 0.002 and P = 0.01, respectively), while the BCVA significantly improved at four months (P = 0.03). In Group 2, the CRT and CRV significantly improved (P < 0.01 and P ≤ 0.01, respectively) during the follow-up period. At four months, both groups showed a recurrence of DME, Group 1 in particular (two-month CRT reduction, -149 ± 127 µm vs four-month CRT reduction, -72 ± 174 µm; P = 0.04). The mean reduction in CRV was significantly different at four months (Group 1, -0.49 ± 1.7 mm3 vs Group 2, -1.3 ± 1.3 mm3 ; P = 0.04). In Group 2, the SRDh significantly decreased at two (P = 0.01) and four months (P = 0.01). Four cases with elevated IOP were managed.

CONCLUSION

DEX implants were found to be effective in different patterns of DME. The SRD pattern may predict a longer-lasting morphologic efficacy.

Intravitreal Dexamethasone Implant as a Sustained Release Drug Delivery Device for the Treatment of Ocular Diseases: A Comprehensive Review of the Literature

Drug delivery into the vitreous chamber remains a great challenge in the pharmaceutical industry due to the complex anatomy and physiology of the eye. Intravitreal injection is the mainstream route of drug administration to the posterior segment of the eye. The purpose of this review is to assess the current literature about the widening use of the intravitreal 0.7 mg dexamethasone (Dex) implant, and to provide a comprehensive collection of all the ocular disorders that benefit from Dex administration. Although anti-vascular endothelial growth-factors (VEGFs) have been largely indicated as a first-choice level, the Dex implant represents an important treatment option, especially in selected cases, such as vitrectomized eyes or patients in whom anti-VEGF failed or are contraindicated. In this article, the safety profile as well as the list of the possible complications related to intravitreal Dex injection are also discussed.

Efficiency analysis by mfERG and OCT of intravitreal injection with ranibizumab on diabetic macular edema

AIM

To analyze the clinical efficacy of intravitreal injection of ranibizumab (IVR) on diabetic macular edema (DME) with multifocal electroretinography (mfERG) and optical coherence tomography (OCT).

METHODS

A total of 41 patients (41 eyes) with DME were treated with IVR. The best corrected visual acuity (BCVA), mfERG results, and OCT were analyzed to compare to the baselines at 1wk, 1, and 3mo after operation.

RESULTS

The BCVA was significantly improved in all eyes at each time point (P<0.001). The macular area leakage and edema were reduced 1wk and 1mo after IVR, and the central fovea thickness (CFT) was significantly reduced compared to baseline (P<0.001). The mfERG, two-dimensional and three-dimensional images all showed that the macular fovea (1 ring) response density decreased, and the fovea and macular area spikes significantly decreased or disappeared. The amplitude density of the P1 wave was increased, and the latency of the P1 wave was shortened than preoperation (P<0.001). At 1wk and 1mo after the operation, there was a negative correlation between the amplitude density of P1 waves and CFT.

CONCLUSION

OCT and mfERG fully demonstrate the importance of IVR for DME patients from the macular morphology and function, especially the significance of mfERG in this disease.

One-year follow-up of ischemic index changes after intravitreal dexamethasone implant for diabetic macular edema: an ultra-widefield fluorescein angiography study

AIM

To investigate late changes in peripheral ischemia in patients affected by diabetic macular edema (DME) and treated with repeated dexamethasone (DEX) intravitreal implants over a 1-year period.

METHODS

In this retrospective cohort study, patients older than 18 years of age and with type 2 non-proliferative treatment-naïve diabetic retinopathy (DR) and DME at baseline were included. All patients were treated with two intravitreal DEX implants within 1 year of follow-up. A minimum of two annual ultra-widefield fluorescein angiography (UWF FA) were required to ensure that all cases had a baseline UWF FA (< 2 weeks before first treatment with dexamethasone) and a UWF FA performed at 12 months of follow-up. On baseline and 1-year UWFA images, peripheral retinal ischemia was quantified using the ischemic index (ISI).

RESULTS

Six eyes of five patients (two males, three females) met the inclusion criteria and were enrolled in this study. Best-corrected visual acuity was 0.34 ± 0.22 LogMAR at baseline and improved to 0.21 ± 0.14 logMAR at the 1-year follow-up visit (P = 0.050). Mean ± SD central macular thickness was 467.6 ± 63.0 μm at baseline and 272.0 ± 14.7 μm at the 1-year follow-up visit (P = 0.043). Mean ± SD ISI was 26.7 ± 14.1% at baseline and reduced to 12.2 ± 5.0% at the 1-year follow-up visit (P = 0.012).

CONCLUSIONS

Improvement in retinal perfusion is still maintained 1 year after starting treatment with DEX implants. This improvement in retinal perfusion might be related to DEX implant-related positive effects on leukostasis.

Real-world experience with pro re nata dosing of intravitreal dexamethasone implant for eyes with refractory diabetic macular edema

Aims: To evaluate treatment outcomes of pro re nata dosing of intravitreal dexamethasone implant in eyes with refractory diabetic macular edema (DME) amongst Indian subjects.

Methods and material: Retrospective, interventional case series. Medical records of 28 eyes of 23 patients with refractory DME who underwent intravitreal dexamethasone (700 µ) implant were reviewed.

Paired t-test was carried out to measure mean change in the parameters evaluated. Mann-Whitney U test and Fisher’s exact t-test were done to explore differences between groups receiving single or multiple injections.

Results: Best corrected visual acuity (BCVA) and central macular thickness (CMT) at baseline were 0.85 (±0.44) and 612 µm (±123), respectively. Mean CMT over 6 months (measured monthly) following injection was 340±119 µm (p=0.001), 346±150 µm (p=0.02), 368±169 µm (p=0.02), 304±174 µm (p=0.001), 525±216 µm (p=0.94) and 532±201 µm (p=0.46), respectively. Mean BCVA at each month following injection was 0.68±0.36 (p=0.02), 0.75±0.45 (p=0.42), 0.55±0.40 (p=0.11), 0.63±0.40 (p=0.12), 0.78±0.30 (p=0.90) and 0.60±0.47 (p=0.92), respectively. Mean follow-up was 12 months (range: 6–33 months). Mean BCVA and CMT at mean 12 months were 0.72±0.46 (p=0.10) and 358 µm±189 (p=0.0001), respectively. Seven eyes had raised IOP; five eyes required cataract extraction.

Conclusions: Intravitreal dexamethasone implant is effective in treatment of refractory DME. However, its therapeutic effect lasts for about 4 months.

Intravitreal dexamethasone implant Ozurdex in the treatment of diabetic macular edema in patients not previously treated with any intravitreal drug: a prospective 12-month follow-up study

Objective: To evaluate the mid-long-term efficacy and safety of the dexamethasone intravitreal (DEX) implant (Ozurdex¹) in naïve patients with diabetic macular edema (DME).Methods: Prospective and single-center study conducted on consecutive patients with a diagnosis of DME, who received a DEX implant and were followed up for at least 12 months. The main outcomes measurements were the mean change in best corrected visual acuity (BCVA) and in foveal thickness (FT) as compared to the baseline values.Results: Of the 84 screened patients 50 were included in the study. The BCVA significantly improved from 52.4 (20.4) letters at baseline to 62.6 (15.6), 61.2 (18.4), 61.6 (18.6), 60.6 (19.0), and 60.6 (18.8) at 2, 4, 6, 12 months and end of follow-up period, respectively (repeated measures ANOVA and the Greenhouse-Geisser correction; p = .0008). At the end of the follow-up period, a gain of BCVA of ≥5, ≥10, and ≥15 letters were observed in 26 (52.0%), 18 (36.0%), and 16 (32.0%) patients, respectively. The mean FT was significantly reduced from 446.0 (139.9) µm at baseline to 327.2 (103.6) at the end of follow-up (repeated measures ANOVA and the Greenhouse-Geisser correction; p = .0008). During the study follow-up, the patients receive a mean of 3.4 (2.9-3.9) implants. Of the 32 phakic eyes at baseline, 17 (53.1%) either developed new lens opacity or progression of an existing opacity.Conclusion: In eyes with DME not previously treated with intravitreal drugs, DEX implants provide meaningful functional and anatomical benefits, and these results are sustained mid-long-term.

Anatomical and functional changes after dexamethasone implant and ranibizumab in diabetic macular edema: a retrospective cohort study

AIM

To investigate the efficacy and safety of ranibizumab (RZB group) and dexamethasone implant (DEX group) intravitreal treatments in patients with treatment-naïve center involved diabetic macular edema (DME) by means of functional and morphological assessments.

METHODS

This retrospective cohort study included 50 eyes of 50 patients with DME treated either with RBZ or DEX. Best-corrected visual acuity (BCVA) and microperimetry were evaluated at baseline and during a 6-month follow-up. In addition, central macular thickness (CMT) by means of structural optical coherence tomography (OCT) and retinal capillary plexus density and choriocapillary density by means of OCT angiography were assessed in all cases.

RESULTS

Functional and morphological parameters significantly improved during the study period in both groups. BCVA improved significantly in both groups with a greater increase in the DEX group compared to the RBZ group (P=0.030). Microperimetry significantly differed during follow-up between the two treatments (P=0.031). In both groups CMT significantly decreased (P<0.001) without statistically significant differences between the two groups. A statistically significant increase of deep capillary plexus density was detected in both groups at 30d after therapy. The retreatment rate was 0.70±0.10 and 0.65±0.10 in the RBZ group and 0.65±0.10 and 0.50±0.11 in DEX group at 120 and 180d respectively. Two out of 25 patients in DEX group showed intraocular pressure increase requiring hypotonic eye drops.

CONCLUSION

Both treatments are very effective for DME treatment during 6mo of follow-up with a lower retreatment rate in DEX group.

Retinal angiographic alteration in diabetic macular edema after dexamethasone implantation: a case report

Here we reported a rare case of the implantation of a dexamethasone intravitreal implant (DEX) in which decreased retinal vessel density (VD) was found by optical coherence tomography angiography (OCTA). A 74-year-old male with diabetes mellitus presented with bilateral macular edema. The best-corrected visual acuity (BCVA) was 0.6 in the right eye. Diabetic macular edema (DME) was diagnosed. A DEX for the right eye was planned, and the preoperative evaluation showed a superficial VD of 48.74 percent, a deep VD of 53.12 percent, and a foveal avascular zone (FAZ) 0.165 mm² in size by OCTA. The BCVA in the right eye recovered to 0.8, and a notably lower superficial VD of 45.97 percent and a deep VD of 45.40 percent were observed with an enlarged FAZ of 0.294 mm² one month postoperatively. Moreover, BCVA in the right eye was maintained at 0.8, while further reductions in both superficial (40.07 percent) and deep (40.91 percent) VD were noted with a FAZ measured at 0.305 mm² two months postoperatively. In conclusion, retinal superficial and deep VD decreased, while the FAZ increased, after the implantation of the DEX in a patient with DME.

Intravitreal dexamethasone implant Ozurdex® in naïve and refractory patients with different subtypes of diabetic macular edema

Background

Diabetic macular edema (DME) can be treated with different alternatives, among them Dexamethasone intravitreal implant 0.7 mg (DEX 0.7) has demonstrated that may improve both central macular thickness (CMT) and best corrected visual acuity (BCVA). This study aimed to evaluate the effect of the intravitreal dexamethasone implant Ozurdex® in patients with different subtypes of diabetic macular edema over a 6-month follow-up period.

Methods

Eighty-four (29 naïve and 55 previously treated) eyes were included in this retrospective study. For each patient, the BCVA [Early Treatment Diabetic Retinopathy Study (ETDRS) charts] and macular thickness on optical coherence tomography (OCT) at baseline visit and within the 2nd, 4th, and 6th months of follow-up were obtained. The main outcomes measurements were the mean change in BCVA and in CMT with respect to the baseline value. The percentage of patients gaining ≥5 letters and ≥ 10 letters in BCVA was also analyzed. Results: A total of 84 eyes, 29 (34.5%) naïve and 55 (65.5%) non-naïve, from 69 patients were included in the study. BCVA at baseline was 58.8 (16.4) and 61.8 (11.6) in naïve and refractory patients, respectively, p = 0.4513. At every visit, BCVA significantly improved from baseline in naïve and non-naïve eyes (p < 0.0001 and p = 0.0003, respectively; Friedman rank sum test). At baseline, the mean CMT was 466.2 (189.7) μm and 448.1 (110.7) μm in the naïve and non-naïve patients, respectively (p = 0.5830); and decreased to 339.3 (92.5) μm and 357.5 (79.1) μm, respectively (p = 0.0004 and p < 0.0001, respectively, Wilcoxon signed-rank test). The proportion of patients gaining ≥10 letters was significantly greater in the naïve group, p = 0.0199.

Conclusion

The intravitreal dexamethasone implant (Ozurdex) is effective for the treatment of diabetic macular edema, even in refractory cases that have failed to respond to previous therapies.

Cost-effectiveness of fluocinolone acetonide implant (ILUVIEN®) in UK patients with chronic diabetic macular oedema considered insufficiently responsive to available therapies

BACKGROUND

Diabetic macular oedema (DMO) may lead to visual loss and blindness. Several pharmacological treatments are available on the National Health Service (NHS) to United Kingdom patients affected by this condition, including intravitreal vascular endothelial growth factor inhibitors (anti-VEGFs) and two types of intravitreal steroid implants, releasing dexamethasone or fluocinolone acetonide (FAc). This study aimed to assess the value for money (cost-effectiveness) of the FAc 0.2 μg/day implant (ILUVIEN®) in patients with chronic DMO considered insufficiently responsive to other therapies.

METHODS

We developed a Markov model with a 15-year time horizon to estimate the impact of changes in best-corrected visual acuity in DMO patients on costs and quality-adjusted life years. The model considered both eyes, designated as the "study eye", defined at model entry as phakic with an ongoing cataract formation or pseudophakic, and the "fellow eye". The model compared the FAc 0.2 μg/day implant with a 700 μg dexamethasone implant (pseudophakic patients only) or with usual care, defined as a mixture of laser photocoagulation and anti-VEGFs (phakic and pseudophakic patients). Costs were estimated from the perspective of the NHS and Personal Social Services; full NHS prices were used for drugs.

RESULTS

In patients who were pseudophakic at baseline, at 36 months, the FAc implant provided an additional gain of 4.01 and 3.64 Early Treatment Diabetic Retinopathy Study (ETDRS) letters compared with usual care and the dexamethasone implant, respectively. Over the 15-year time horizon, this translated into 0.185 additional quality-adjusted life years (QALYs) at an extra cost of £3066 compared with usual care, and 0.126 additional QALYs at an extra cost of £1777 compared with dexamethasone. Thus, incremental cost-effectiveness ratios (ICERs) were £16,609 and £14,070 per QALY gained vs. usual care and dexamethasone, respectively. In patients who were phakic at baseline, the FAc 0.2 μg/day implant provided an additional gain of 2.96 ETDRS letters at 36 months compared with usual care, which, over 15 years, corresponded to 0.11 additional QALYs at an extra cost of £3170, resulting in an ICER of £28,751 per QALY gained.

CONCLUSION

The FAc 0.2 μg/day implant provided good value for money compared with other established treatments, especially in pseudophakic patients.

Long-term efficacy and safety profile of multiple injections of intravitreal dexamethasone implant to manage diabetic macular edema: A systematic review of real-world studies

INTRODUCTION

Systematic review of real-world studies about repeated dexamethasone intravitreal implant (DEXi) 0.7 mg in diabetic macular edema management, in order to identify the effective window of time occurring between injections, the critical evaluation of efficacy of the treatment, and the relative long-term safety in the real life setting.

METHODS

Literature databases such as PubMed, SCOPUS, and EMBASE were used to identify reports including DEX implant injections.

RESULTS

Twenty-one peer-reviewed publications were identified. DEX implants retreatment was considered on a pro re nata (PRN) basis at any time or starting from month three or four. About 1/3 of the eyes were retreated before six months from first injection (range 0-86.7%). Mean retreatment average time was 5.3 ± 0.9 months, with an estimated average of 1.3 injections each six months. There was no statistical correlation between average retreatment time and incidence of adverse events or other variables investigated. Limited safety issues related to implants number have been found, suggesting an overall good tolerance of long-term DEXi.

CONCLUSIONS

Comprehensive evaluation of real-world data suggests an average DEXi duration close to five months, following a PRN treatment strategy, including about 1/3 of patients. Repeated DEXi administration revealed an acceptable long-term efficacy/safety ratio.

Pharmacological Management of Diabetic Macular Edema in Real-Life Observational Studies

OBJECTIVES OF THE STUDY

of observational studies concerning the pharmacological management of diabetic macular edema (DME).

METHODS

A literature review was conducted using the PubMed database on 1 February 2018 to identify studies evaluating the efficacy of anti-VEGF and dexamethasone (DEX) implants for DME. Studies with more than 10 patients and follow-up of more than 6 months were selected. Analyses were carried out on the overall population and on subgroups defined according to baseline visual acuity (BVA) and the patients' naïve or non-naïve status.

RESULTS

Thirty-two studies evaluating the efficacy of anti-VEGF and 31 studies evaluating the efficacy of DEX-implants were retained, concerning 6,842 and 1,703 eyes, respectively. A mean gain of +4.7 letters for a mean of 5.8 injections (mean follow-up: 15.6 months) and +9.6 letters for a mean of 1.6 injections (10.3 months) was found in the anti-VEGF and DEX-implant studies, respectively. Final VA appears to be similar for both treatment (62 letters for anti-VEGF, 61.2 letters for DEX-implant), and BVA appears lower for DEX-implant, which may partially explain the greater visual gain. The DEX-implant studies show greater gains in VA compared to the anti-VEGF studies, especially for higher BVA. Indeed, mean gains for the subgroups of patients with BVA<50 letters, 5060 letters are +4.3, +5.8, and +3.1 letters, respectively, in the anti-VEGF studies and +10.5, +9.3, and +8.8 letters, respectively, in the DEX-implant studies. Regarding the patient's initial status, only naïve status appears to confer the best functional response in DEX-implant studies.

CONCLUSION

Observational studies investigating DEX-implant report clinically similar final VA when compared to anti-VEGF, but superior visual gains in real-life practice. This latter difference could be due to the better BVA, but also to the fact that less injections were administered in the anti-VEGF observational studies than in the interventional studies.

Macular edema resolution assessment with implantable dexamethasone in diabetic retinopathy (MERIT): a pilot study

Purpose

This study aimed to evaluate the effect of dexamethasone implantation on the hard exudates (HEX) in patients with diabetic macular edema (DME).

Study design

This was a nonrandomized open-label single-center prospective trial.

Methods

This study included 15 eyes of 11 subjects with DME. Key inclusion criteria were naïve eyes with DME with HEX within 3 mm of fovea with center-involving DME; central macular thickness (CMT) >250 μm at baseline; best-corrected visual acuity (BCVA) between 20/400 and 20/40. Key exclusion criteria were previous intraocular surgery and history of panretinal photocoagulation (PRP) in past 4 months. The primary outcome measure was change in total HEX area at the macula (in mm²) measured by semiautomated algorithm. Secondary outcome measures were change in visual acuity, low-contrast visual acuity (LCVA), retinal sensitivity (RS) on macular microperimetry, and CMT.

Results

The total HEX area reduced from 1.5 mm² (±1.46 mm²) at baseline to 0.89 mm² (±1.062 mm²) at the final visit (p=0.185). The CMT improved significantly (p=0.03) from 488.67 μm (±240.66 μm) to 326.93 μm (±135.84 μm) at the final visit. Mean BCVA remained stable (p=0.95) (50.93±16.65 at baseline and 50.6±18.95 at final visit). The mean LCVA and RS showed insignificant improvement (p=0.31 and p=0.28, respectively).

Conclusion

Our pilot study demonstrated an improving trend in reduction of total HEX area and other anatomical outcomes, with limited functional outcomes. Larger randomized studies with a larger sample size with a control group are warranted to establish management protocols for DME with significant subfoveal HEX.

SAFETY OF CONSECUTIVE SAME-DAY BILATERAL INTRAVITREAL DEXAMETHASONE IMPLANT (OZURDEX)

PURPOSE

The objective of this study was to evaluate patient safety and tolerance of consecutive bilateral intravitreal dexamethasone (Ozurdex) injections during a single visit for the treatment of cystoid macular edema secondary to retinal vein occlusion, diabetic macular edema, or noninfectious posterior uveitis.

METHODS

This was a retrospective single-center institutional review board-approved study from March 1, 2013, through August 1, 2016. All patients had a complete ophthalmologic examination and optical coherence tomography imaging. Bilateral intravitreal dexamethasone (Ozurdex) injection was performed according to standard sterile procedure. Twelve patients (24 eyes) were included in the study.

RESULTS

A total of 48 injections were administered to 24 eyes of 12 patients that qualified for the study. Patients received intravitreal dexamethasone (Ozurdex) injections for treatment of diabetic macular edema (10 patients), retinal vein occlusion (1 patient), or noninfectious posterior uveitis (1 patient). There were no complications.

CONCLUSION

Consecutive same-day bilateral intravitreal dexamethasone (Ozurdex) is safe and well tolerated. There were no significant complications, and patients preferred continuing bilateral implantation after their initial trial. Same-day treatment may optimize efficiency and decrease patient visits and ultimate treatment burden without compromising patient safety or clinical efficacy.

Current Clinical Application of Microperimetry: A Review

Microperimetry (MP) is a technology that allows the study of retinal sensitivity at different foveal and parafoveal areas as well as eye fixation. It is a technique of functional evaluation, providing a direct correlation between anatomical and functional outcomes. There are a great variety of studies which evaluate the repeatability or reliability of measurements obtained with this technology and also describe and explore different clinical applications. MP has been shown to be useful in the characterization of sensory and motor conditions, such as amblyopia or nystagmus. Concerning ocular pathology, several studies have confirmed the usefulness of MP for evaluating and analyzing different retinal pathological conditions, such as age-related macular degeneration or glaucoma, and for analyzing the effect of different medical or surgical treatments for these conditions. MP has also been shown to be useful for visual training or rehabilitation in some specific cases.

Multifocal electroretinography changes at the 1-year follow-up in a cohort of diabetic macular edema patients treated with ranibizumab

PURPOSE

To determine the changes in the multifocal electroretinogram (mfERG) at 1 year in a clinical series of diabetic macular edema (DME) patients treated with ranibizumab (RNBZ) using a pro re nata protocol.

METHODS

We analyzed a clinical series of 35 eyes of 35 patients with DME at baseline and after treating them with RNBZ over 1 year, in order to determine the change in the macular function, which was assessed by means of the response density and the implicit time of the first-order kernel (FOK) P1 wave of the mfERG at the foveola (R1), fovea (R2) and parafovea (R3). These electrophysiological parameters were studied taking into account different independent variables, such as DME type, degree of diabetic retinopathy (DR), level of preservation of both the ellipsoid zone (IS/OS) and the external limiting membrane (ELM) and changes in central retinal thickness (CRT) and total macular volume (TMV). We also studied the relationship between the response density and the best-corrected visual acuity (BCVA).

RESULTS

Eyes with cystic and spongiform DME showed better response density with respect to the serous type (p < 0.001) at baseline. Similarly, eyes with high IS/OS and ELM preservation rates showed higher initial response density compared to the others (p < 0.001). Eyes with moderate DR had better response density compared to those with severe and proliferative DR (p = 0.001). At the beginning of the study, those eyes with proliferative and severe DR showed longer implicit times with respect to those with moderate DR (p = 0.04). The response density significantly increased in eyes that anatomically restored the IS/OS and the ELM after being treated with RNBZ (both p < 0.001). Similarly, eyes with spongiform DME further improved the response density with respect to those with cystic and serous DME (p < 0.001). On the contrary, eyes with hard exudates showed less improvement in their response density at the end of the study (p < 0.001). We observed a significant relationship between BCVA and the response density achieved at the end of the study (p = 0.012). Eyes with severe and proliferative DR significantly shortened implicit time compared to those with moderate DR (p = 0.04).

CONCLUSIONS

The multifocal electroretinogram allowed us to differentiate groups of eyes with DME according to their electrophysiological profile, both initially and after being treated with RNBZ. Ranibizumab increased the response density in all DME types included in the study, with a maximum response in those eyes with spongiform type. Once treated with RNBZ, the macular electrophysiological activity improved in eyes that had a well-preserved ellipsoid zone and ELM. The presence of hard exudates was a limitation to the response density achieved at the foveola.

Qualitative and Quantitative Assessment of Vascular Changes in Diabetic Macular Edema after Dexamethasone Implant Using Optical Coherence Tomography Angiography

The aim of this study was to investigate retinal and choriocapillaris vessel changes in diabetic macular edema (DME) after the intravitreal dexamethasone implant (IDI) using optical coherence tomography angiography (OCTA). Moreover, a comparison between morphological and functional parameters of DME and healthy patients was performed. Twenty-five eyes of 25 type 2 diabetic retinopathy patients complicated by macular edema (DME group) and 25 healthy subjects (control group) were enrolled. Superficial capillary plexus density (SCPD) and deep capillary plexus density (DCPD) in the foveal and parafoveal areas, choricapillary density (CCD) and optic disc vessel density (ODVD) were detected using OCTA at baseline and after 7, 30, 60, 90 and 120 days post injection. Best corrected visual acuity (BCVA), retinal sensitivity, and central retinal thickness (CMT) were also evaluated in both groups of patients. A statistically significant difference between the two groups (DME and controls) was found in terms of functional (MP, p < 0.001 and BCVA, p < 0.001) and morphological (CMT, p < 0.001; SCPD in the parafoveal area, p < 0.001; DCPD in the foveal area, p < 0.05 and parafoveal area, p < 0.001; CCD, p < 0.001) parameters. After the treatment, SCPD and DCPD in the foveal and parafoveal areas did not modify significantly during the follow up.

Oxidative stress and diabetic retinopathy: development and treatment

Diabetic retinopathy (DR) is the most common microvascular complication in diabetic patients and one of the main causes of acquired blindness in the world. From the 90s until date, the incidence of this complication has increased. Reactive oxygen species (ROS) is a free radical with impaired electron that usually participates in the redox mechanisms of some body molecules such as enzymes, proteins, and so on. In normal biological conditions, ROS is maintained in equilibrium, however its overproduction can lead to biological process called oxidative stress and this is considered the main pathogenesis of DR. The retina is susceptible to ROS because of high-energy demands and exposure to light. When the balance is broken, ROS produces retinal cell injury by interacting with the cellular components. This article describes the possible role of oxidative stress in the development of DR and proposes some treatment options based on its stages. The review of the topic shows that blindness caused by DR can be avoided by early detection and timely treatment.

Surgical Versus Medical Treatment for Diabetic Macular Edema: A Review

We aimed to compare the results of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling, an alternative therapeutic strategy, with those of medical treatment for chronic macular edema. We conducted a review of the literature on the microscopic, anatomical, and functional reasons for performing PPV with ILM peeling in patients with diabetic macular edema (DME). We searched the PubMed database for articles published between 2000 and 2017. We used the medical subject heading "vitrectomy diabetic macular edema" and the keywords "diabetic macular edema", "internal limiting membrane peeling", "pars plana vitrectomy", "diabetic retinopathy", and "optical coherence tomography". Analysis of the literature revealed that cytokines, vascular endothelial growth factor, reactive oxygen species (ROS), and advanced glycation end-products (AGEs) play a unique role in DME. The vitreous cavity serves as a physiological reservoir for all inflammatory molecules. AGE receptors are localized at the footplates of Müller cells and the external limiting membrane (ELM). The footplates of Müller cells are in contact with the ILM, which suggests that they might be responsible for the structural damage (i.e., thickening) observed in the ILM of patients with DME. Therefore, PPV could allow a reduction of cytokines and pro-inflammatory molecules from the vitreous cavity. ILM peeling could eliminate not only the physical traction of a thickened structure, but also the natural reservoir of AGEs, ROS, and inflammatory molecules. PPV with ILM peeling is a surgical option that should be considered when treating patients with chronic DME.

An eighteen-month follow-up study on the effects of Intravitreal Dexamethasone Implant in diabetic macular edema refractory to anti-VEGF therapy

AIM

To evaluate the long-term efficacy and safety of dexamethasone implants in subjects affected by diabetic macular edema (DME) resistant to anti-vascular endothelial growth factor (VEGF) therapy.

METHODS

Thirty-two DME patients were enrolled. A 700 microgram slow release Intravitreal Dexamethasone Implant (Ozurdex^®) was placed in the vitreous cavity. All patients were followed for 18mo. Best-corrected visual acuity (BCVA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS) and central macular thickness (CMT) exams were carried out at baseline (T0) and after 1 (T1), 3 (T3), 4 (T4), 6 (T6), 9 (T9), 12 (T12), 15 (T15), and 18mo (T18) post injection.

RESULTS

Repeated measures ANOVA showed an effect of treatment on ETDRS (P<0.0001). Post hoc analyses revealed that ETDRS values were significantly increased at T1, T3, T4, T9, and T15 (P<0.001) as compared to baseline value (T0). At T6, T12, and T18, ETDRS values were still statistically higher than baseline (P<0.001 vs T0). However, at these time points, we observed a trend to return to baseline conditions. ANOVA also showed an effect of treatment (P<0.0001). CMT decreased significantly at T1, T3, T4, T9, and T15 (P<0.001). At T6 (P<0.01), T12 and T18 (P<0.001) CMT was also significantly lower than T0 although a trend to return to the baseline conditions was also observed.

CONCLUSION

Our findings demonstrate that Intravitreal Dexamethasone Implant is a good option to improve BCVA and CMT in DME patients resistant to anti-VEGF therapy. Our data also show that the use of drugs administered directly into the vitreous allows achieving appropriate and long-lasting concentration at the site of disease without systemic side effects.