Combination of Intravitreal Bevacizumab and Topical Dorzolamide versus Intravitreal Bevacizumab Alone for Diabetic Macular Edema: A Randomized Contralateral Clinical Trial

Anatomic biomarkers as potential endpoints in diabetic macular edema: A systematic literature review with identification of macular volume as a key surrogate for visual acuity

Optimization of diabetic macular edema (DME) treatment pathways can aid in the efficient introduction of new therapies that provide value to patients and healthcare systems. We performed a systematic literature review and multicorrelation analysis to identify and evaluate anatomic biomarkers as potential surrogate endpoints (SEs) for visual acuity (VA) in patients with DME. We performed EMBASE and MEDLINE searches to identify studies reporting on 4 priority biomarkers previously identified by clinical experts: hyperreflective foci, intraretinal cyst, macular volume (MV), and subretinal fluid. Endpoint and treatment effect correlation analyses were performed to establish correlation coefficients between MV and VA using Pearson's correlation. A total of 105 studies reported change from baseline data for VA, and at least 1 biomarker, with MV investigated most often (n = 70 studies). Data extracted from 55 studies focusing on the 6-mm zone for MV were used in statistical analyses. A moderate correlation was observed between MV and VA at the endpoint level (r = 0.58; p < 0.01); however, a corresponding treatment effect was not found (r = 0.32; p = 0.19). Our findings suggest MV's potential as an SE for VA in future clinical practice; however, the lack of a significant treatment effect warrants that these findings be interpreted cautiously. Further evidence and improvements in reporting the methods for collecting biomarker data are needed. Analysis of outliers and subanalyses by other optical coherence tomography measures could establish the most meaningful MV values correlating with VA.

Intravitreal Bevacizumab Alone Vs Combined With Topical Timolol-Dorzolamide or Dorzolamide for Diabetic Macular Edema: A Systematic Review and Meta-Analysis

Purpose

Diabetic macular edema (DME) is a major cause of vision loss in diabetes. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of intravitreal bevacizumab (IVB) combined with topical timolol-dorzolamide versus dorzolamide alone in DME patients.

Patients and Methods

A literature search was conducted across multiple databases until March 2024. Randomized controlled trials (RCTs) comparing IVB (1.25 mg, monthly) with topical dorzolamide-timolol (twice daily) or dorzolamide alone (twice daily) were included. Primary outcomes assessed were best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) at various intervals.

Results

Four RCTs involving 98 patients (150 eyes) were analyzed, with a mean age of 57.9 years and a female predominance (55.1%). The subgroup meta-analysis indicated a weighted mean difference (WMD) in BCVA of -0.125 [95% CI: -0.21 to -0.041]. The IVB+D group showed no significant difference in WMD compared to the IVB and IVB+TD groups. IOP measurements revealed a WMD of -1.244 mmHg [95% CI: -2.548 mmHg to 0.06 mmHg], with a significant increase in the IVB group compared to the IVB+D and IVB+TD groups. CMT analysis showed a WMD of -78.875 μm [95% CI: -118.606 μm to -39.145 μm], with no significant differences among groups.

Conclusion

Concurrent IVB with topical timolol-dorzolamide or dorzolamide alone demonstrated similar efficacy in improving BCVA and CMT in DME patients. However, the IVB+TD combination resulted in a more significant reduction in IOP compared to IVB alone.

Non-steroidal intravitreal injection for noninfectious uveitic cystoid macular edema: Systematic review and meta-analysis

PURPOSE

To systematically review the published manuscripts on the non-steroidal intravitreal injection for treatment of noninfectious uveitic cystoid macular edema (CME).

METHODS

The PubMed, Scopus, and Web of Science, Science Direct, ProQuest, Cochrane Library, ProQuest, Embase, Clinical Key, and Springer were searched for relevant articles published until May 2022. The random-effects models were used to estimate the mean difference (MD) and 95% confidence interval (CI) for postoperative central macular thickness (CMT) and visual acuity (VA) changes. VA was transformed into the logarithm of the minimum angle of resolution (LogMAR). Meta-regression was conducted for adjusting the effects of potential confounders.

RESULTS

A total of 17 relevant studies (258 eyes) were included in this meta-analysis. A significant improvement was observed in CMT in the last follow up (350.89 ± 108.43) compared to the baseline (452.3 ± 112.67) (Log MD = 1.82, 95% CI = 1.62, 2.02; I2 = 57.7%; P = 0.002). Additionally, VA also significantly improved in the last follow up (0.56 ± 0.29) compared to the baseline (0.75 ± 0.3) (Exponential MD = 0.82, 95% CI = 0.69, 0.95; I2 = 0.0%; P = 0.98). The subgroups analyzed included ten studies on anti-vascular endothelial growth factors (VEGF), three studies on infliximab, two studies on methotrexate (MTX), and two studies on diclofenac. All subgroups showed a significant improvement in both CMT and VA at the last follow-up (P < 0.05).

CONCLUSION

Non-steroidal intravitreal injection including bevacizumab, ranibizumab, infliximab, MTX and diclofenac appears to be an effective treatment option for noninfectious uveitic CME.

The effect of combination therapy with intravitreal bevacizumab and topical timolol-dorzolamide eye drops on diabetic macular edema: a double-blind randomized controlled trial

BACKGROUND

The mainstay of treatment in diabetic macular edema (DME) is intravitreal administration of anti-vascular endothelial growth factors (anti-VEGFs). Aqueous depressants may enhance the effects of anti-VEGF agents by prolonging their clearance via aqueous outflow.

PURPOSE

To compare the anatomical and functional outcomes of treatment with intravitreal bevacizumab (IVB) and topical timolol-dorzolamide versus IVB alone.

METHOD

In this randomized placebo-controlled clinical trial, patients with center-involving DME (ci-DME) and best corrected visual acuity (BCVA) of 20/30 or less were enrolled and randomly allocated to two treatment arms. One group received three monthly IVB injections and timolol-dorzolamide eye drops twice a day (IVB + TD group); the other group received three monthly IVB injections and artificial tear drops as placebo (IVB group). Patients underwent ophthalmic evaluations and macular optical coherence tomography scans at baseline and 1 month after the third injection.

RESULT

Forty-six eyes from 46 patients with ci-DME were recruited. There was no intergroup difference regarding age, gender distribution, diabetic retinopathy stage, glycemic indices, BCVA, central macular thickness (CMT), or intraocular pressure at baseline. BCVA was significantly improved in the IVB + TD group (0.46 ± 0.18 to 0.36 ± 0.18 logarithm of the minimum angle of resolution [logMAR], p = 0.002), in contrast to IVB group (0.40 ± 0.17 to 0.35 ± 0.22 logMAR, p = 0.113). Similarly, the IVB + TD group showed a significant reduction in CMT (p < 0.001), unlike the IVB group (p = 0.086); and the CMT change in the former was greater than in the latter (- 0.57 ± 57.67 vs. - 25.52 ± 68.02 μm, p = 0.033).

CONCLUSION

Our findings support the short-term effectiveness of topical timolol-dorzolamide as adjunctive therapy to IVB injections in managing center-involving DME in terms of anatomical and visual outcomes.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05083689 (October 19, 2021).

Topical Dorzolamide as Adjunctive Treatment With Intravitreal Bevacizumab in Bilateral Diabetic Macular Edema

BACKGROUND

 Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is accepted as the gold standard treatment for center-involving diabetic macular edema (CI-DME). Adjunctive administration of topical dorzolamide may enhance the therapeutic effects of anti-VEGF agents. In this study, we compared the efficacy of topical dorzolamide plus intravitreal injection of bevacizumab (IVB) versus IVB alone in patients with bilateral DME.

METHODS

This prospective, randomized contralateral eye study was carried out in a tertiary referral ophthalmology center, Al-Zahra Eye Hospital, Zahedan, Iran, between April 2021 and April 2022. This study included 50 eyes of 25 patients with bilateral DME. All eyes received three consecutive monthly injections of IVB. For each patient, one eye was randomized to instill dorzolamide eye drops three times a day as an intervention, and the other received artificial tear drops as a placebo. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) were evaluated before starting treatment and then monthly for the first three months.

RESULTS

Among 25 included patients, the average age was 56.64 ± 7.97 years, and 48% were female. BCVA did not improve significantly in any groups (P > 0.05). No significant difference was observed in terms of BCVA between the intervention and control groups (P > 0.05). The present study showed a decrease in CMT in both study groups (P < 0.05). At month 3, the decrease in mean CMT from baseline was significantly higher in eyes receiving topical dorzolamide compared to the control group (-88.92 ± 82.90 vs. -37.64 ± 86.16 µM, respectively; P = 0.037). IOP decreased significantly only in eyes receiving dorzolamide (P < 0.001).

CONCLUSIONS

The results of the present study indicate that adjunctive administration of topical dorzolamide has a beneficial effect on CMT reduction from baseline, but it did not have an additive effect on BCVA improvement compared to IVB monotherapy.

Prophylactic intraocular pressure lowering measures in anti-vascular endothelial growth factor therapy: A systematic review and meta-analysis

Acute intraocular pressure (IOP) elevation following repeat intravitreal anti-vascular endothelial growth factor (VEGF) injections (IVI) may pose a risk to the integrity of the retinal nerve fiber (RNFL). This meta-analysis investigates the role of IOP-lowering interventions such as an anterior chamber paracentesis (ACP) and IOP-lowering medications on the IOP in patients undergoing IVIs. MEDLINE, EMBASE, and the Cochrane Library were searched up to February, 2021. Studies investigating IOP-lowering interventions in patients undergoing IVI versus controls were included. The primary outcome was the IOP in the short- and long-term post-IVI. Secondary outcomes were changes in the RNFL thickness and best corrected visual acuity (BCVA). ACP at time of anti-VEGF injection significantly lowered IOP immediately post anti-VEGF (WMD: -27.98 mm Hg, P < 0.001). Patients in the ACP group also had significantly thicker RNFL compared to control (WMD: 2.07 um, P < 0.00001) at median follow-up of 16.5 months. IOP-lowering medications (on the day of injection or in the long-term) significantly reduced IOP up to 30 minutes after injection (WMD: -3.31 mm Hg, P = 0.003). This effect was statistically significant between the 2 arms up to 1 month follow-up. There was no difference in BCVA in intervention versus controls. ACP reduces immediate IOP spikes post-IVI and preserves the RNFL in the short- and longterms IOP-lowering medications also reduce IOP spike, with limited data on RNFL thickness.

Inflammation in diabetic retinopathy: possible roles in pathogenesis and potential implications for therapy

Diabetic retinopathy, characterized as a microangiopathy and neurodegenerative disease, is the leading cause of visual impairment in diabetic patients. Many clinical features observed in diabetic retinopathy, such as capillary occlusion, acellular capillaries and retinal non-perfusion, aggregate retinal ischemia and represent relatively late events in diabetic retinopathy. In fact, retinal microvascular injury is an early event in diabetic retinopathy involving multiple biochemical alterations, and is manifested by changes to the retinal neurovascular unit and its cellular components. Currently, intravitreal anti-vascular endothelial growth factor therapy is the first-line treatment for diabetic macular edema, and benefits the patient by decreasing the edema and improving visual acuity. However, a significant proportion of patients respond poorly to anti-vascular endothelial growth factor treatments, indicating that factors other than vascular endothelial growth factor are involved in the pathogenesis of diabetic macular edema. Accumulating evidence confirms that low-grade inflammation plays a critical role in the pathogenesis and development of diabetic retinopathy as multiple inflammatory factors, such as interleukin-1β, monocyte chemotactic protein-1 and tumor necrosis factor -α, are increased in the vitreous and retina of diabetic retinopathy patients. These inflammatory factors, together with growth factors such as vascular endothelial growth factor, contribute to blood-retinal barrier breakdown, vascular damage and neuroinflammation, as well as pathological angiogenesis in diabetic retinopathy, complicated by diabetic macular edema and proliferative diabetic retinopathy. In addition, retinal cell types including microglia, Müller glia, astrocytes, retinal pigment epithelial cells, and others are activated, to secrete inflammatory mediators, aggravating cell apoptosis and subsequent vascular leakage. New therapies, targeting these inflammatory molecules or related signaling pathways, have the potential to inhibit retinal inflammation and prevent diabetic retinopathy progression. Here, we review the relevant literature to date, summarize the inflammatory mechanisms underlying the pathogenesis of diabetic retinopathy, and propose inflammation-based treatments for diabetic retinopathy and diabetic macular edema.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.

Efficacy of topical dorzolamide 2% in diabetic cystoid macular edema

AIM

To study the effect of topical dorzolamide 2% on macular thickness reduction in diabetic cystoid macular edema (CME).

METHODS

This was a prospective, non-randomized, open study including eyes with diabetic macular edema (DME). All eyes received topical dorzolamide 2% three times daily for one month. Changes in best-corrected visual acuity (BCVA), and central macular thickness (CMT) by optical coherence tomography) were evaluated at 1wk, 1, and 3mo post-treatment.

RESULTS

Ninety-three eyes (84 patients) were included. Mean±SD (logMAR) BCVA improved significantly from 1.08±0.26 pretreatment to 0.66±0.24 at 1mo and 0.87±0.26 at 3mo post-treatment (P<0.001 both). The mean±SD CMT was significantly reduced from 535.27±97.4 µm at baseline to 357.43±125.8 µm at 1mo and 376.23±114.5 µm at 3mo post-treatment (P<0.001 both). No significant ocular or systemic side effects were recorded.

CONCLUSION

Topical dorzolamide 2% results in significant improvement of mean BCVA and reduction of mean CMT at 3mo post-treatment. It can be used as an effective, affordable, and safe therapy for treatment of non-refractory diabetic CME.