Short-term Efficacy of Intravitreal Dexamethasone Implant in Vitrectomized Eyes with Recalcitrant Diabetic Macular Edema and Prior Anti-VEGF Therapy

Comparison of ranibizumab, aflibercept, and dexamethasone implant monotherapy in treatment-naive eyes with diabetic macular edema: A 12-month real-life experience

PURPOSE

To compare the functional and anatomical outcomes of ranibizumab, aflibercept, and dexamethasone implant monotherapy in treatment-naive eyes with diabetic macular edema (DME) in real-life conditions.

METHODS

In this retrospective cohort study, data were obtained from the hospital database of treatment-naive patients diagnosed with DME with at least 12 months of follow-up. Best corrected visual acuity (BCVA) and central retinal thickness (CRT) at baseline, third month, sixth month, ninth month, and 12th month were recorded. In addition, a subgroup analysis was performed based on having good (below 0.4 log of minimum angle of resolution [logMAR]) or poor (0.4 logMAR and above) vision.

RESULTS

A total of 219 eyes of 142 patients were included in the study. The change in the mean BCVA from baseline to 12th month was from 0.62 logMAR to 0.42 logMAR (P < 0.001) in the ranibizumab group, from 0.56 logMAR to 0.39 logMAR (P < 0.001) in the aflibercept group, and from 0.46 logMAR to 0.5 logMAR (P = 0.653) in the dexamethasone group. There was no significant difference between the treatment groups at any time point (P > 0.05). The mean amount of CRT change was statistically significant at 12 months in all groups (ranibizumab: -175.4 µm, aflibercept: -153.3 µm, dexamethasone: -71.4 µm) (P < 0.05). In eyes with initially good vision, the final BCVA at 12 months was significantly better in the ranibizumab group compared to the dexamethasone group (P = 0.008). The aflibercept group had better visual acuity than the dexamethasone group, but there was no statistically significant difference (P = 0.059). There was no significant difference in final BCVA in eyes with initially poor vision. No serious ocular/systemic complications were noted.

CONCLUSION

At the 12th month, a significant decrease in CRT was achieved in all treatment groups, whereas only ranibizumab and aflibercept groups had a significant BCVA increase. In eyes with initially good vision, the final BCVA at 12 months was better in the ranibizumab group compared to the dexamethasone group, whereas it was similar in all groups having initially poor vision.

A Review on Diabetic Retinopathy

Diabetic retinopathy is a well-recognised microvascular complication of diabetes and is among the leading cause of blindness all over the world. Over the last decade, there have been advances in the diagnosis of diabetic retinopathy and diabetic macular edema. At the same time, newer therapies for the management of diabetic retinopathy have evolved. As a result of these advances, a decline in severe vision loss due to diabetes has been witnessed in some developing countries. However, there is a steady increase in the number of people affected with diabetes, and is expected to rise further in the coming years. Therefore, it is prudent to identify diabetic retinopathy, and timely intervention is needed to decrease the burden of severe vision loss. An effort has been made to review all the existing knowledge regarding diabetic retinopathy in this article and summarize the present treatment options for diabetic retinopathy.

Updates on the Current Treatments for Diabetic Retinopathy and Possibility of Future Oral Therapy

Diabetic retinopathy (DR) is a complication of diabetes and one of the leading causes of vision loss worldwide. Despite extensive efforts to reduce visual impairment, the prevalence of DR is still increasing. The initial pathophysiology of DR includes damage to vascular endothelial cells and loss of pericytes. Ensuing hypoxic responses trigger the expression of vascular endothelial growth factor (VEGF) and other pro-angiogenic factors. At present, the most effective treatment for DR and diabetic macular edema (DME) is the control of blood glucose levels. More advanced cases require laser, anti-VEGF therapy, steroid, and vitrectomy. Pan-retinal photocoagulation for non-proliferative diabetic retinopathy (NPDR) is well established and has demonstrated promising outcomes for preventing the progressive stage of DR. Furthermore, the efficacy of laser therapies such as grid and subthreshold diode laser micropulse photocoagulation (SDM) for DME has been reported. Vitrectomy has been performed for vitreous hemorrhage and tractional retinal detachment for patients with PDR. In addition, anti-VEGF treatment has been widely used for DME, and recently its potential to prevent the progression of PDR has been remarked. Even with these treatments, many patients with DR lose their vision and suffer from potential side effects. Thus, we need alternative treatments to address these limitations. In recent years, the relationship between DR, lipid metabolism, and inflammation has been featured. Research in diabetic animal models points to peroxisome proliferator-activated receptor alpha (PPARα) activation in cellular metabolism and inflammation by oral fenofibrate and/or pemafibrate as a promising target for DR. In this paper, we review the status of existing therapies, summarize PPARα activation therapies for DR, and discuss their potentials as promising DR treatments.

Anti-VEGF-Resistant Retinal Diseases: A Review of the Latest Treatment Options

Anti-vascular endothelial growth factor (anti-VEGF) therapy currently plays a central role in the treatment of numerous retinal diseases, most notably exudative age-related macular degeneration (eAMD), diabetic retinopathy and retinal vein occlusions. While offering significant functional and anatomic benefits in most patients, there exists a subset of 15–40% of eyes that fail to respond or only partially respond. For these cases, various treatment options have been explored with a range of outcomes. These options include steroid injections, laser treatment (both thermal therapy for retinal vascular diseases and photodynamic therapy for eAMD), abbreviated anti-VEGF treatment intervals, switching anti-VEGF agents and topical medications. In this article, we review the effectiveness of these treatment options along with a discussion of the current research into future directions for anti-VEGF-resistant eyes.

Effectiveness and Safety of Coadministration of Intravitreal Dexamethasone Implant and Silicone Oil Endotamponade for Proliferative Diabetic Retinopathy with Tractional Diabetic Macular Edema

Purpose: To investigate the efficacy and safety of coadministered intravitreal dexamethasone (IVD) implant and silicone oil endotamponade during pars plana vitrectomy (PPV) for the treatment of proliferative diabetic retinopathy (PDR) with tractional diabetic macular edema (DME). Methods: In this prospective, controlled, and randomized clinical study, the eyes with PDR and vitreomacular traction syndrome that underwent PPV with silicone oil endotamponade were divided into 2 groups. Group 1 was defined as the control group, and no other procedures were performed. IVD was implanted to the eyes in Group 2. In both groups, panretinal photocoagulation was completed to the missed areas during PPV. All cases followed for 6 months, postoperatively. Retinal findings were followed with optical coherence tomography and fluorescein fundus angiography. Results: A total of 52 eyes of 52 patients were included in the study. Twenty-six eyes of 23 patients were included in both groups. The improvement in best corrected visual acuity was statistically significantly higher in Group 2 (P > 0.05). In the postoperative period, the DME development rate and intravitreal ranibizumab (IVR) injection requirement were significantly higher in Group 1 (P > 0.05). There was no statistically significant difference in the proliferative vitroretinopathy development rate between the groups (P < 0.05). Conclusion: Coadministration of IVD implant and silicone oil endotamponade to the eyes with PDR during vitrectomy seems to be safe and effective application and may decrease the rate of DME and the requirement of IVR injection.

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.

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.

Use of intravitreal dexamethasone implants in the treatment of diabetic macular edema: Expert recommendations using a Delphi approach

Objective:

The aim of this study is to develop guidance on the use of intravitreal dexamethasone implants in the treatment of diabetic macular edema.

Method:

The study was performed using the modified Delphi method to obtain a consensus among a panel of experts on management of patients with diabetic macular edema and use of intravitreal dexamethasone implants in clinical practice. Thirty-seven panel members, experts on retina, from different Spanish centers were invited to participate. Individual and anonymous opinions were asked by answering a 76-item questionnaire across 11 topic areas (two rounds were done). Level of agreement was assessed using a Likert-type scale of 9 points.

Results:

Agreement on “consensus” was reached during the first round in 63 items. The 13 remaining items underwent a second round of voting. After the second round, agreement on “consensus” was reached on five items. Finally, eight items remained without consensus.

Conclusion:

Intravitreal dexamethasone implants are useful in the treatment of patients with diabetic macular edema with different profiles, for example, pseudophakic, poor-adherents, vitrectomized, candidates for cataract surgery, patients with high inflammatory component, and with a history of cardiovascular events. The use of intravitreal dexamethasone reduces the number of visits and facilitates compliance. Experts thought that the switch from anti-vascular endothelial growth factor therapy to intravitreal dexamethasone implants should be done preferably after three injections. Also, pro re nata treatment provides better results in diabetic macular edema patients as it helps to prevent undertreatment. Finally, experts concluded that clinical guidelines and treatment protocols for diabetic macular edema need to be updated.

Dexamethasone Implant in Patients with Diabetic Macular Edema Resistant to Anti-VEGF Therapy

Objectives:

To investigate the efficacy of single dose intravitreal dexamethasone implant in patients with diabetic macular edema (DME) resistant to anti-VEGF therapy.

Materials and Methods:

Twenty eyes of 14 patients (8 male, 6 female; mean age, 65±5.7 years) with DME resistant to intravitreal ranibizumab injections were studied. A single intravitreal dexamethasone implant was injected into each eye and patients were followed up for 6 months. Response to therapy was assessed monthly by measuring intraocular pressure (IOP), best-corrected visual acuity (BCVA), and central foveal thickness (CFT).

Results:

Baseline (before injection) IOP was 14.9±2.7 mmHg and did not change significantly in the six months following injection. Baseline BCVA was 1.04±0.35 LogMAR and improved to 0.86±0.31 at month 1 without statistical significance (p=0.056). CFT was significantly lower in all monthly measurements compared to its baseline value of 682.2±229.2 μm. During the follow-up period, endophthalmitis, significant cataract, or rhegmatogenous retinal detachment were not detected.

Conclusion:

Intravitreal dexamethasone implant injection is associated with significant CFT reduction for up to six months without causing any complications. Although BCVA did not improve in parallel with the CFT reduction, intravitreal dexamethasone implant should be considered as an effective and safe treatment option in the management of DME patients resistant to anti-VEGF injections.

Pharmacological Adjuncts to Vitrectomy Surgery

Pharmacological adjuncts to vitrectomy surgery are useful tools to better deal with surgery. Their introduction has enriched the therapeutic choice before, during and after operations. Although several classifications could be made to frame adjuncts to vitrectomy, we preferred to divide the pharmacological adjuncts to vitrectomy surgery for therapeutic use in the pre-operatory procedure (neo-adjuvant), for intraoperative use and for post-operatory practice (adjuvant). This type of classification allowed us to explore all the adjuncts based on the timing of their use. The actual interest in vitrectomy surgery is giving rise to considerable interest in new molecules with and without the pharmacological effect that will soon be available for the aid of vitreoretinal surgery.

Comparison of the Effect of Intravitreal Dexamethasone Implant in Vitrectomized and Nonvitrectomized Eyes for the Treatment of Diabetic Macular Edema

Purpose

To compare the effectiveness of sustained-release dexamethasone (DEX) intravitreal implant in nonvitrectomized eyes and vitrectomized eyes with diabetic macular edema (DME).

Methods

A retrospective review of the medical records of 40 eyes of 30 consecutive patients with diabetic macular edema who underwent intravitreal DEX implant injection. Patients were divided into 2 subgroups: 31 eyes that were nonvitrectomized (group 1) and 9 eyes that had previously undergone standard pars plana vitrectomy (group 2). The main outcome measures were BCVA and foveal thickness (FT).

Results

A significant improvement was seen in BCVA in both group 1 and group 2 at the 1st, 2nd, and 6th months after treatment with DEX implant (p < 0.05). In group 1, a significant reduction in FT was observed at the 1st, 2nd, and 6th months (p < 0.05). In group 2, a significant reduction in FT was seen at the 1st and 2nd months (p < 0.05), but the reduction rate at the 6th month after the injection was not statistically significant (p = 0.06).

Conclusion

DEX implant is effective for the treatment of diabetic macular edema, and the effectiveness of the drug is similar in vitrectomized and nonvitrectomized eyes.

Intravitreal anti-VEGF agents, oral glucocorticoids, and laser photocoagulation combination therapy for macular edema secondary to retinal vein occlusion: preliminary report

AIM

To evaluate the efficacy and safety of combined anti-vascular endothelial growth factor (VEGF) agents, oral glucocorticoid, and laser photocoagulation therapy for macular edema (ME) secondary to retinal vein occlusion (RVO).

METHODS

This study included 16 eyes of 16 patients with RVO-associated ME. Patients were initially treated with oral prednisone and an intravitreal anti-VEGF agent. Two weeks later, patients underwent standard laser photocoagulation. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), and retinal vessel oxygenation were examined over 12mo.

RESULTS

Patients received 1.43±0.81 anti-VEGF injections. Mean baseline and 12-month logMAR BCVA were 0.96±0.51 (20/178) and 0.31±0.88 (20/40), respectively, in eyes with central retinal vein occlusion (CRVO) (P<0.00), and 1.02±0.45 (20/209) and 0.60±0.49 (20/80), respectively, in eyes with branch retinal vein occlusion (BRVO) (P<0.00). At 12mo, CRT had significantly decreased in eyes with CRVO (P<0.00) and BRVO (P<0.00). Venous oxygen saturation had significantly increased in eyes with CRVO (P<0.00) and BRVO (P<0.00). No examined parameters were significantly different between the 2 RVO groups. No serious adverse effects occurred.

CONCLUSION

Anti-VEGF, glucocorticoid, and photocoagulation combination therapy improves visual outcome, prolongs therapeutic effect, and reduces the number of intravitreal injections in eyes with RVO-associated ME.

Drug-resistant coagulase-negative staphylococcal endophthalmitis following dexamethasone intravitreal implant

A 60-year-old female came to our hospital with defective vision due to persistent diabetic macular edema and was treated with intravitreal ozurdex implant in the right eye. Three days later, the patient presented with diminution of vision, ocular pain, congestion, and hypopyon with no fundus view. B-scan ultrasonography showed vitritis, and diagnosis of endophthalmitis was made. Subsequently, 25-gauge pars plana vitrectomy was performed along with intravitreal vancomycin and amikacin and removal of implant. On culture, there was growth of coagulase-negative staphylococcus which was resistant to ofloxacin antibiotic. A week following treatment, there was significant improvement in the patient's sign and symptoms with improvement in vision. Our case demonstrated that acute endophthalmitis can occur following dexamethasone intravitreal implant.

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.

Therapeutic Options in Refractory Diabetic Macular Oedema

Diabetic macular oedema (DMO) results from alterations of several biochemical pathways in diabetic eyes. Centre-involving DMO is an important cause of visual loss in diabetes. Anti-vascular endothelial growth factor agents are now the mainstay of centre-involving DMO treatment. Oedema that does not achieve optimal response to these agents occurs in a sizeable proportion of eyes and is called refractory or persistent DMO. Management of refractory DMO is challenging. In this paper, the pathophysiology of DMO, and the definitions used in various studies are summarised. Therapeutic options for refractory DMO management including corticosteroids, laser, combination therapies, and surgery are explored. Novel agents on the horizon for DMO control that are being investigated at present are discussed as well. A literature review was performed and a summary of the research studies for each of the agents is provided in order to guide the reader regarding the existing evidence for their application in DMO. Importance of early recognition of disease and prompt treatment to achieve best visual outcome is discussed. Utility of optical coherence tomography to guide disease diagnosis and monitoring is highlighted. An algorithmic approach for DMO management is described. Finally, the impact that personalized medicine and genetics might have on DMO management is assessed.

Pharmaceutical technology can turn a traditional drug, dexamethasone into a first-line ocular medicine. A global perspective and future trends

Dexamethasone is one of the most prescribed glucocorticoids. It is effective and safe in the treatment of a wide variety of ocular conditions, including anterior and posterior segment inflammation. However, its half-life in the vitreous humor is very short, which means that it typically requires frequent administrations, thus reducing patient adherence and causing therapeutic failure. Innovative dexamethasone delivery systems have been designed in an attempt to achieve sustained release and targeting. The FDA has approved dexamethasone implants for the treatment of macular edema secondary to retinal vein occlusion and posterior segment noninfectious uveitis. Lenses, micro- and nanoparticles, liposomes, micelles and dendrimers are also proving to be adequate systems for maintaining optimal dexamethasone levels in the site of action. Pharmaceutical technology is turning a classical drug, dexamethasone, into a fashionable medicine.

Contralateral eye-to-eye comparison of intravitreal ranibizumab and a sustained-release dexamethasone intravitreal implant in recalcitrant diabetic macular edema

Objective

To compare the effects of intravitreal ranibizumab (RZB) or dexamethasone (DEX) intravitreal implant in cases of recalcitrant diabetic macular edema (DME).

Methods

Retrospective, interventional study examining patients with symmetric bilateral, center-involved DME recalcitrant to treatment with RZB, who received DEX in one eye while the contralateral eye continued to receive RZB every 4–5 weeks for a study period of 3 months.

Results

Eleven patients (22 eyes) were included: mean logarithm of the minimal angle of resolution (logMAR) visual acuity (VA) for the DEX arm improved from 0.415 (standard deviation [SD] ±0.16) to 0.261 (SD ±0.18) at final evaluation, and mean central macular thickness (CMT) improved from 461 µm (SD ±156) to 356 µm (SD ±110; net decrease: 105 µm, P=0.01). Mean logMAR VA for the RZB arm improved from 0.394 (SD ±0.31) to 0.269 (SD ±0.19) at final evaluation. Mean CMT improved from 421 µm (SD ±147) to 373 µm (SD ±129; net decrease: 48 µm, P=0.26).

Conclusion

A subset of recalcitrant DME patients demonstrated significant CMT reduction and VA improvement after a single DEX injection.