Oscillatory Photodynamic Therapy for Choroidal Neovascularization and Central Serous Retinopathy; a Pilot Study

Purpose: To report the preliminary results of oscillatory photodynamic therapy (OPDT) for choroidal neovascularization (CNV) and central serous retinopathy (CSR). Methods: This study included 7 eyes of 6 patients with CSR (2 eyes), idiopathic CNV (2 eyes), CNV due to age-related macular degeneration (AMD) (2 eyes), and peripapillary CNV secondary to presumed ocular histoplasmosis syndrome (1 eye). Intravenous verteporfin (6 mg/m2 body surface area) was infused over 10 minutes followed by oscillating laser (wavelength 689 nm) covering slightly beyond the entire lesion. An Area Centralis lens was applied and laser was delivered (600 mW/cm2 fluence rate and 50 J/cm2 dose). Intravitreal bevacizumab and dexamethasone combination therapy was used with OPDT in 4 eyes with CNV; intravitreal dexamethasone and triamcinolone acetonide were injected in the other eye with CNV. Clinical examination, funduscopy, fluorescein angiography, and optical coherence tomography (OCT) were performed at baseline and after treatment. Results: After mean follow-up of 7.1±5.1 months, visual acuity improved from 0.87±0.69 logMAR (20/160) to 0.60±0.65 logMAR (20/80) (P = 0.027); central foveal thickness decreased from 322±62.1 to 240.7±34.8 microns as measured by OCT (P = 0.018). Fluorescein angiography and OCT demonstrated cessation of vascular leakage, and resolution of hemorrhage and subretinal fluid in all eyes. No adverse events or recurrence were noted. Conclusion: OPDT was effective in treating CNV lesions and CSR. OPDT may be an improvement on standard PDT due to reduced side effects, thermal damage and scarring

Oxygen Nanobubbles-Embedded Hydrogel as Wound Dressing to Accelerate Healing

Herein, we propose an oxygen nanobubbles-embedded hydrogel (ONB-G) with carbopol for oxygenation of wounds to accelerate the wound healing process. We integrate carbopol, hydrogel, and dextran-based oxygen nanobubbles (ONBs) to prepare ONB-G where ONBs can hold and release oxygen to accelerate wound healing. Oxygen release tests showed that the proposed ONB-G could encapsulate oxygen in the hydrogels for up to 34 days; meanwhile, fluorescence studies indicated that the ONB-G could maintain high oxygen levels for up to 4 weeks. The effect of carbopol concentration on the oxygen release capacity and rheological features of the ONB-G were also investigated along with the sterility of ONB-G. HDFa cell-based studies were first conducted to evaluate the viability, proliferation, and revival of cells in hypoxia. Scratch assay and mRNA expression studies indicated the potential benefit for wound closure. Histological evaluation of tissues with a pig model with incision and punch wounds showed that treatment with ONB-G exhibited improved healing compared with hydrogel without ONBs or treated without the gel. Our studies show that dextran-shell ONBs embedded in a gel (ONB-G) have the potential to accelerate wound healing, given its oxygen-holding capacity and release properties