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Central retinal artery occlusion (CRAO) is an obstruction of the retinal artery carrying oxygen to the cells in the inner retinal layers. This lack of oxygen may result in irreversible loss of sight if not treated within 24−36 h. We propose a dextranbased oxygen nanobubble (DONB) platform for intravitreal delivery of oxygen to rescue the inner retina from such ischemic damage. The size distribution of DONBs was 119.6 ± 44.9 nm and the zeta (ζ)-potential was −35.54 ± 10.54 mV. The DONBs were found to be stable in amber vials at 5 ± 3 °C for over 4 months and the formulation was not cytotoxic. The therapeutic efficacy of DONBs was first evaluated in retinal precursor cell lines which showed excellent recovery and then in a hypoxia/reperfusion rat eye model. Oxygen distribution measurements and histology indicated excellent recovery of the ganglion and inner retinal cell layers. Electroretinography exhibited normal retinal function. Our unique approach suggests a promising pathway to treat CRAO, a blinding condition for which no effective treatment exists.

Purpose: This work aimed to assess postoperative outcomes associated with relaxing parafoveal nasal retinotomy for refractory macular hole repair. Methods: This was a retrospective interventional study of patients with persistent or recurrent macular holes following 1 or more standard repair procedures with pars plana vitrectomy and internal limiting membrane peeling. Patients received an additional pars plana vitrectomy and relaxing parafoveal nasal retinotomy, followed by fluid-air and air-gas exchange. Key postoperative outcomes included the achievement of macular hole closure and changes in visual acuity from baseline. Results: Thirteen patients with refractory macular holes were included, with a median age of 65 years (range, 49-90 years). The aperture diameter of the 13 macular holes ranged from 180 to 799 µm (median, 538 µm). Vitrectomy and relaxing parafoveal nasal retinotomy were performed in all 13 eyes, and after a median follow-up of 12 months (range, 3-34 months), anatomical closure was achieved in 12 of 13 eyes (92.3%). Overall, visual acuity (mean ± SE) improved significantly from 1.20 ± 0.15 logMAR (approximate Snellen equivalent, 20/320) at baseline to 0.84 ± 0.11 logMAR (Snellen, ∼ 20/125) during postoperative follow-up ( P < .05). Central and paracentral scotomas were observed in 8 of 11 eyes with postoperative Humphrey visual field 10-2 and/or 24-2 data available. Conclusions: Relaxing parafoveal nasal retinotomy may be an effective method to promote anatomical closure and improve vision outcomes in patients with recalcitrant macular holes.