Diabetic macular edema: Safe and effective treatment with intravitreal triamcinolone acetonide (Taioftal)

Improved triamcinolone acetonide-eluting contact lenses based on cyclodextrins and high hydrostatic pressure assisted complexation

Contact lenses (CLs) constitute an advantageous platform for the topical release of corticosteroids due to their prolonged contact with the eye. However, the lipophilic nature of corticosteroids hampers CLs' ability to release therapeutic amounts. Two approaches to improve loading and release of triamcinolone acetonide (TA) from poly(2-hydroxyethyl methacrylate)-based hydrogels were investigated: adding 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) to the monomers solution before polymerization (HEMA/i-CD) and an hydrogels' post-treatment with HP-β-CD (HEMA/p-CD). The effect of HP-β-CD and sterilization by high hydrostatic pressure (HHP) on the hydrogel properties (water content, oxygen and ion permeability, roughness, transmittance, and stiffness) was evaluated. The HEMA/i-CD hydrogels had stronger affinity for TA, sustaining its release for one day. HHP sterilization promoted the formation of cyclodextrin-TA complexes within the hydrogels, improving their drug-loading capacity »60 %. Cytotoxicity and irritability tests confirmed the safety of the therapeutic CLs. TA released from the hydrogels permeated through ocular tissues ex vivo and showed anti-inflammatory activity. Finally, a previously validated mathematical model was used to estimate the ability of the TA-loaded CLs to deliver therapeutic drug concentrations to the posterior part of the eye. Overall, HP-β-CD-containing CLs are promising candidates for the topical ocular application of TA as an alternative delivery system to intraocular injections.

The Treatment of Diabetic Retinal Edema with Intravitreal Steroids: How and When

Diabetic macular edema (DME) is a common complication of diabetes mellitus and a leading cause of visual impairment worldwide. It is defined as the diabetes-related accumulation of fluid, proteins, and lipids, with retinal thickening, within the macular area. DME affects a significant proportion of individuals with diabetes, with the prevalence increasing with disease duration and severity. It is estimated that approximately 25-30% of diabetic patients will develop DME during their lifetime. Poor glycemic control, hypertension, hyperlipidemia, diabetes duration, and genetic predisposition are recognized as risk factors for the development and progression of DME. Although the exact pathophysiology is still not completely understood, it has been demonstrated that chronic hyperglycemia triggers a cascade of biochemical processes, including increased oxidative stress, inflammation, activation of vascular endothelial growth factor (VEGF), cellular dysfunction, and apoptosis, with breakdown of the blood-retinal barriers and fluid accumulation within the macular area. Early diagnosis and appropriate management of DME are crucial for improving visual outcomes. Although the control of systemic risk factors still remains the most important strategy in DME treatment, intravitreal pharmacotherapy with anti-VEGF molecules or steroids is currently considered the first-line approach in DME patients, whereas macular laser photocoagulation and pars plana vitrectomy may be useful in selected cases. Available intravitreal steroids, including triamcinolone acetonide injections and dexamethasone and fluocinolone acetonide implants, exert their therapeutic effect by reducing inflammation, inhibiting VEGF expression, stabilizing the blood-retinal barrier and thus reducing vascular permeability. They have been demonstrated to be effective in reducing macular edema and improving visual outcomes in DME patients but are associated with a high risk of intraocular pressure elevation and cataract development, so their use requires an accurate patient selection. This manuscript aims to provide a comprehensive overview of the pathology, epidemiology, risk factors, physiopathology, clinical features, treatment mechanisms of actions, treatment options, prognosis, and ongoing clinical studies related to the treatment of DME, with particular consideration of intravitreal steroids therapy.

Comparison of the Effect of Bromfenac versus Betamethasone Ophthalmic Solutions in Patients with Diabetic Macular Edema

PURPOSE

To examine the effect of 0.1% bromfenac (BF) ophthalmic solution and 0.1% betamethasone (BM) ophthalmic solution on diabetic macular edema (DME).

METHODS

This was a prospective trial. Nineteen patients (mean age of 66.6 ± 10.1 years) with DME and mean retinal thickness within a diameter of 1 mm from the fovea (central subfield thickness: CST) of 250-500 µm were randomized and instilled with BF or BM. CST, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were measured at 4, 8, and 12 weeks after administration.

RESULTS

CST at baseline (p = .128) and that at 4, 8, and 12 weeks of administration was not significantly different between the BF (10 patients) and BM groups (9 patients). In patients with glycated hemoglobin (HbA1c) <8.0%, CST, compared with baseline, was significantly decreased in the BF group (seven patients) at 8 (p = .025) and 12 weeks (p = .043) of administration. When compared with the baseline, no significant changes in BCVA were observed at any point in time in either group. Baseline IOP was comparable between the groups. In the BM group, the values of change in IOP from baseline significantly increased at 8 (p = .025) and 12 weeks (p = .044) of administration, with no significant changes in IOP over the 12 weeks of administration in the BF group.

CONCLUSIONS

BF did not affect IOP even after 12 weeks of administration, suggesting its effect in reducing CST in DME with good glycemic control.

TRIAL REGISTRATION

University Hospital Medical Information Network (UMIN-CTR); UMIN000026201, February 18, 2017; Japan Registry of Clinical Trials; jRCTs031180308, March 15, 2019.