OBJECTIVE: To determine whether intravitreal injection of recombinant tissue plasminogen activator (rTPA) is effective for the treatment of refractory diabetic macular edema (DME) in patients who already had posterior vitreous detachment (PVD).
METHODS: It is a retrospective chart review of the patients with refractory DME and PVD. The efficacy of intravitreal injection of rTPA was assessed based on the changes in central macular thickness (CMT) and best-corrected visual acuity (BCVA) in these patients.
RESULTS: Nine eyes of nine patients as the study group and 14 eyes of the 14 patients as the control group were examined. Before the injections, the mean CMT was 470.0± 107.6 in the study group, compared to 536.2± 150.5 in the control group, with no statistical significance (p=0.403). The statistical analysis revealed no significant differences in the mean changes in CMT from baseline to one and three months after injections between the study and control groups (p=0.439, p=0.781, respectively). Likewise, no statistically significant disparities were observed in the mean pre-injection BCVA between the study group (0.877± 0.349) and the control group (0.950± 0.300) (p=0.415). Additionally, after three months of injection, there were no significant changes in the mean BCVA of the study group (0.844± 0.304) and the control group (0.864± 0.253) (p=0.512).
CONCLUSIONS: This study showed that rTPA has no effect on changes in CMT and BCVA in patients who had refractory DME and PVD at the same time. This may suggest that the improvement in CMT in previous studies may be due to the induction of PVD.

BACKGROUND: To evaluate the additive effect of topical or sub-tenon injection of interferon (IFN)-α 2b in the treatment of refractory diabetic macular edema.
METHODS: In this prospective study patients with center-involved DME who were unresponsive to 3 monthly consecutive IVB injections were recruited. Patients were divided into three groups: group1, received IFN- α 2b topical drop at a dose of 1mIU/ml four times a day for 3 months. Group 2, received a single sub-tenon injection of 1mIU/ml IFN- α 2b at the enrollment. Group 3 received artificial tears four times a day for 3 months (control group). All groups received three consecutive monthly IVB injections and were evaluated monthly up to 1 month following the last IVB injection.
RESULTS: In this study, 59 eyes of 35 patients with refractory DME were assessed. The final follow-up showed that although CMT decreased in all groups, only patients in Group 2 had statistically significant lower CMT compared to their baseline values (change in CMT: - 117 ± 213 µm; p-value = 0.025). Comparison of CMT changes between three groups showed no statistically significant difference, although it was higher in group 2 (change in CMT: - 117 ± 213 µm (Group2) vs. - 49 ± 173 (Group 1) vs. - 36 ± 86 (Group 3); p-value = 0.085). Considering eyes with baseline CMT > 400 µm, sub-tenon injection of IFN α2b led to a significant reduction of CMT at the first month and final follow-up visit (CMT change: - 166 ± 210, - 145 ± 231 µm; p-value = 0.018 and 0.035, respectively). In this subgroup, eyes in Group 2 had lower CMT at the first month following treatment in comparison with the control group (CMT: 444 ± 123 µm vs. 544 ± 96 µm, p-value = 0.042). Alterations of CDVA were not statistically significant among groups, although patients in Group 1 had a significant improvement in vision at second and last follow up (CDVA change: - 0.23 ± 0.39, - 0.20 ± 0.43 logMAR; p-value = 0.030 and 0.010, respectively).
CONCLUSIONS: In short term, Sub-tenon injection of IFN might have an additive anatomical effect in eyes with refractory DME. Validation of this observation requires further prospective controlled studies.

OBJECTIVE: The purpose of this study is to compare the efficacy of intravitreal ranibizumab (IVR) alone and concurrent IVR with posterior subtenon triamcinolone acetonide (PSTA) injection for patients with diabetic macular edema (DME) refractory to IVR monotherapy.
METHODS: We enrolled 43 eyes of 43 patients with DME who received at least three times of IVR, which resulted in poor anatomical responses, with central foveal thickness (CFT) reduction <10% and postinjection CFT >300 μm. All the eyes received initial 3 monthly then pro re nata (PRN) IVR 0.5-mg injections. Twenty eyes continued PRN injections and 23 eyes received combined IVR 0.5 mg and PSTA 40 mg with at least 1-year follow-up. Best-corrected visual acuity (BCVA) and CFT were recorded from 1-month to 1-year follow-up.
RESULTS: Following switch to combined therapy, the mean BCVA significantly improved from 0.61 ± 0.32 logarithm of the minimum angle of resolution (logMAR) to 0.45±0.39 logMAR at 6 month (P = 0.003), 0.43±0.35 logMAR at 9 months (P < 0.001), and 0.48±0.45 logMAR at 1 year (P = 0.03). In eyes with IVR alone, no significant VA improvement was noted throughout the year. Significantly better BCVA was noted in the combined group at 6-month, 9-month, and 1-year follow-up compared to IVR-alone group. The timing of combined therapy showed a significant association with 1-year BCVA (t = 3.25, P = 0.018).
CONCLUSIONS: Concurrent IVR and PSTA resulted in significantly better visual outcomes in 1-year follow-up for those refractory to preceding ranibizumab monotherapy for DME. Early addition of PSTA predicted a better visual outcome.

Introduction: To evaluate the effectiveness and safety of intravitreal dexamethasone (DEX) implants in refractory diabetic macular edema (DME) treated by intravitreal ranibizumab. Materials and Methods: We retrospectively analyzed DME patients who received DEX implant treatment after being refractory to at least 3 monthly intravitreal ranibizumab injections. The main outcomes were best-corrected visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP). Results: Twenty-nine eyes of 26 patients who had previously received an average of 8.1 ± 4.4 ranibizumab injections were included. Patients received between one and three DEX implants during 12.4 ± 7.4 months of follow-up. The mean final CRT significantly decreased from 384.4 ± 114.4 μm at baseline to 323.9 ± 77.7 μm (p = 0.0249). The mean final BCVA was 51.4 ± 21.3 letters, which was not significant compared to baseline (44.9 ± 30.2 letters, p = 0.1149). Mean IOP did not increase significantly. All patients tolerated the treatment well without serious adverse events. Higher baseline CRT and worse BCVA correlated with better therapeutic responses. Conclusion: Switching to DEX implant is feasible and safe for treating patients of DME refractory to intravitreal ranibizumab in real world. Further larger-scale or multicenter studies would be conducted to explore different DEX treatment strategies for DME, such as first-line or early switch therapy, for better BCVA improvement.

OBJECTIVE: To provide 2-year follow-up data on eyes with diabetic macular edema (DME) that were non-responsive after three initial anti-vascular endothelial growth factor (VEGF) injections, comparing functional and anatomical outcomes under continued anti-VEGF therapy versus dexamethasone (DEX) implant.
METHODS: Multicenter, retrospective chart review comparing eyes with treatment-naïve DME and a suboptimal response to a loading phase of anti-VEGF therapy (3 injections given monthly) which were then treated with (a) further anti-VEGF (n = 72) or (b) initially switched to DEX implant (n = 38). Main outcome measures were change in visual acuity (VA) and central subfield thickness (CST) from the end of the loading phase to 24 months.
RESULTS: In 79% of the 12-month study population (87/110 eyes), 24-month data were available. One quarter of eyes in each group switched treatments during the second year. Eyes that were switched early to DEX implant maintained the functional and anatomical improvements at 24 months which were seen in the first year (from month 3: + 8.9 letters, - 214 µm). Eyes that were switched from anti-VEGF therapy to steroids in the second year improved VA and reduced CST at 24 months (from month 12: + 6.8 letters, p = 0.023; - 226 µm, p = 0.004). In eyes continued on anti-VEGF therapy, VA and CST were stable at 24 months (from month 3: + 2.8 letters, p = 0.254; - 24 µm, p = 0.243). Eyes that were non-responsive to anti-VEGF therapy for 12 months had similar chances to experience a VA gain from further therapy as eyes that were non-responsive for 3 months only (23.8 vs. 31.0%, p = 0.344).
CONCLUSIONS: The beneficial effect of an early switch to DEX implant in DME non-responders seen at month 12 was maintained during the second year. A later switch from anti-VEGF to steroids still provided significant improvement. Eyes continued on anti-VEGF over a period of 24 months maintained vision. A quarter of eyes, which had not improved vision at 12 months, exhibited a delayed response to treatment.

OBJECTIVE: To compare functional and anatomical outcomes of continued anti-vascular endothelial growth factor (VEGF) therapy versus dexamethasone (DEX) implant in eyes with refractory diabetic macular edema (DME) after three initial anti-VEGF injections in a real-world setting.
METHODS: To be included in this retrospective multicenter, case-control study, eyes were required: (1) to present with early refractory DME, as defined by visual acuity (VA) gain ≤ 5 letters or reduction in central subfield thickness (CST) ≤ 20%, after a loading phase of anti-VEGF therapy (three monthly injections) and (2) to treat further with (a) anti-VEGF therapy or (b) DEX implant. Main outcome measures were change in visual acuity (VA) and central subfield thickness (CST) at 12 months. Due to imbalanced baseline characteristics, a matched anti-VEGF group was formed by only keeping eyes with similar baseline characteristics as those in the DEX group.
RESULTS: A total of 110 eyes from 105 patients were included (anti-VEGF group: 72 eyes, DEX group: 38 eyes). Mean change in VA at 12 months was - 0.4 ± 10.8 letters (anti-VEGF group), and + 6.1 ± 10.6 letters (DEX group) (P = 0.004). Over the same period, mean change in CST was + 18.3 ± 145.9 µm (anti-VEGF group) and - 92.8 ± 173.6 µm (DEX group) (P < 0.001). Eyes in the DEX group were more likely to gain ≥ 10 letters (OR 3.71, 95% CI 1.19-11.61, P = 0.024) at month 12.
CONCLUSIONS: In a real-world setting, eyes with DME considered refractory to anti-VEGF therapy after three monthly injections which were switched to DEX implant and had better visual and anatomical outcomes at 12 months than those that continued treatment with anti-VEGF therapy.

OBJECTIVE: To evaluate the efficacy of vitrectomy, membranectomy, and internal limiting membrane (ILM) peeling on macular thickness and best corrected visual acuity (BCVA) in patients with refractory diffuse diabetic macular edema (DME) and non-tractional epiretinal membrane (NT-ERM).
METHODS: This prospective interventional case series included eyes with refractory DME (central subfield macular thickness [CSMT] > 300 μm) after at least two intravitreal injections of bevacizumab (IVB) and one intravitreal injection of triamcinolone (IVT), and accompanying NT-ERM. Complete ophthalmic examination, baseline spectral domain optical coherence tomography (SD-OCT), and fluorescein angiography (FA) were performed prior to 23 gauge pars plana vitrectomy with membranectomy and internal limiting membrane (ILM) peeling. Postoperative evaluation was done with clinical examination and SD-OCT. Linear mix model analysis was used to study postoperative results.
RESULTS: Twelve eyes from 11 patients (5 males) with a mean age of 60.33 ± 9.01 (range 46-73 years) were included. The mean follow-up time was 13.5 ± 4.48 months (range 4-20 months). A significant reduction in CSMT was found (from 559 ± 89 μm to 354 ± 76 μm; P = 0.001), with a non-significant BCVA change (from 0.84 ± 0.32 logMAR to 0.72 ± 0.2 logMAR; P = 0.967). There was no significant correlation between CSMT and BCVA (partial correlation = -0.115, P = 0.445) and also between estimated mean CSMT change per month and estimated mean BCVA change per month (r = 0.337, P = 0.283).
CONCLUSIONS: In this series, our results did not show that vitrectomy, membranectomy, and ILM peeling result in significant improvement of BCVA in eyes with refractory DME and non-tractional ERM in spite of central macular thickness reduction.

OBJECTIVE: To report the long-term results of intravitreal bevacizumab (IVB) injection alone or combined, at the time of first IVB injection, with intravitreal triamcinolone acetonide (IVT) for treatment of refractory diabetic macular edema (DME).
METHODS: In this randomized clinical trial, 115 eyes of 101 patients with refractory DME were enrolled and randomly assigned to one of the three study arms: the IVB group (41 eyes) received three consecutive injections of 1.25 mg IVB at 6-week intervals; the IVB/IVT group (37 eyes) additionally received 2 mg of IVT at the time of first IVB injection; and the control (sham injection) group. Patients in the IVB and IVB/IVT groups were followed for a mean of 13.3 months and received retreatment with IVB alone whenever indicated. Main outcome measures were best corrected visual acuity (BCVA) and central macular thickness (CMT).
RESULTS: At the last follow up, CMT decreased significantly in the IVB group (p=0.013) but it was not significant (p=0.13) in the IVB/IVT group. Mean CMT improvement was 91 (95% CI, 20 to 161) microns and 57 (95% CI, -18 to 133) microns in the IVB and IVB/IVT groups, respectively. Mean BCVA improvement from baseline was 0.28 (95% CI, 0.18 to 0.38) logMAR (P=0.017) in the IVB group and 0.19 (95% CI, 0.08 to 0.30) logMAR (P=0.001) in the IVB/IVT group. There was no difference between the two groups in terms of visual improvment (p=0.42). In generalized linear mixed model, only the time interval between the last injection and CMT measurement was statistically significant (P=0.04). The same results were repeated for visual acuity (P=0.03).
CONCLUSIONS: Three loading doses of IVB (added doses if required) have long-term beneficial effects for treatment of refractory DME. Adding triamcinolone to this regimen provides no additional long-term benefit.