Extracellular matrix (ECM) supplies both physical and chemical signals to cells and provides a substrate through which fibroblasts migrate during wound repair. To directly assess how ECM composition regulates this process, we used a nested 3D matrix model in which cell-populated collagen buttons were embedded in cell-free collagen or fibrin matrices. Time-lapse microscopy was used to record the dynamic pattern of cell migration into the outer matrices, and 3-D confocal imaging was used to assess cell connectivity and cytoskeletal organization. Corneal fibroblasts stimulated with PDGF migrated more rapidly into collagen as compared to fibrin. In addition, the pattern of fibroblast migration into fibrin and collagen ECMs was strikingly different. Corneal fibroblasts migrating into collagen matrices developed dendritic processes and moved independently, whereas cells migrating into fibrin matrices had a more fusiform morphology and formed an interconnected meshwork. A similar pattern was observed when using dermal fibroblasts, suggesting that this response in not unique to corneal cells. We next cultured corneal fibroblasts within and on top of standard collagen and fibrin matrices to assess the impact of ECM composition on the cell spreading response. Similar differences in cell morphology and connectivity were observed – cells remained separated on collagen but coalesced into clusters on fibrin. Cadherin was localized to junctions between interconnected cells, whereas fibronectin was present both between cells and at the tips of extending cell processes. Cells on fibrin matrices also developed more prominent stress fibers than those on collagen matrices. Importantly, these spreading and migration patterns were consistently observed on both rigid and compliant substrates, thus differences in ECM mechanical stiffness were not the underlying cause. Overall, these results demonstrate for the first time that ECM protein composition alone (collagen vs. fibrin) can induce a switch from individual to collective fibroblast spreading and migration in 3-D culture. Similar processes may also influence cell behavior during wound healing, development, tumor invasion and repopulation of engineered tissues.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy of systemic prostaglandin E1 (PGE1) infusion within the first 24 hours of acute central retinal artery occlusion (CRAO). PATIENTS AND METHODS: Best corrected visual acuity (BCVA) was analyzed in a case series of six eyes from six patients (mean age: 69.33 years) with acute CRAO who were treated with twice-daily intravenous infusion of 40 μg PGE1. Therapy continued until the patient no longer experienced visual acuity improvements for 24 hours. RESULTS: Average time to presentation was 8.33 hours (range: 2 to 12 hours). The logMAR BCVA at presentation was 2.73. BCVA at the final visit 1 month after initial presentation was 1.48 ( P = .025). All patients experienced vision improvement. No systemic adverse events were experienced. CONCLUSION: Intravenous PGE1 infusion resulted in significant visual improvement in patients presenting with acute CRAO and is well tolerated with few adverse effects. [ Ophthalmic Surg Lasers Imaging Retina . 2019;50:S5–S8.]

With recent advancements in vitreoretinal surgical machines, surgical incisions have become less traumatic and fluidics control has led to a more controlled posterior segment vitrectomy.

Purpose: To report optical coherence tomography angiography findings obtained in two patients with solar retinopathy.Methods: Two case reports.Results: Two patients presented with blurry vision after sun gazing during the recent solar eclipse and were found to have characteristic foveal lesions on examination and optical coherence tomography consistent with solar retinopathy. Optical coherence tomography angiography showed a focal area of nonperfusion of the choriocapillaris in the affected eyes.Conclusion: Changes to the choriocapillaris layer on optical coherence tomography angiography in two patients with solar retinopathy suggest that damage is not limited to the retina.

Background To evaluate the accuracy of intravitreal injection volume of the pre-filled syringe (PFS) in which aflibercept is packaged compared to the BD Luer-Lok 1-mL syringe. Methods Ophthalmologists injected their typical intravitreal volume for aflibercept using either the PFS or BD Luer-Lok 1-mL syringe for 5 times each. The injected fluid was weighed using a micro-scale and converted to volume. The volume of fluid injected was also evaluated when the 0.05 mL line on the PFS was lined up to the tip or base of the dome-shaped plunger. Results Injection volume was measured for 12 physicians. The average injected fluid volume was 74.22 ± 15.87 µL for PFS and 53.42 ± 4.61 µL for the BD Luer-Lok 1-mL syringe (p < 0.0001). The average deviation in volume injected for the PFS was higher compared to the BD Luer-Lok 1-mL syringe (11.36 µL vs. 3.35 µL, p < 0.0001). When the PFS was lined up with the tip of the dome-shaped plunger at the 0.05-mL line, the average injected volume was 71.03% higher. Conclusions The intravitreal injection volume and variability using the new PFS were significantly higher than the volume injected using the BD Luer-Lok 1-mL syringe previously used, potentially leading to higher rates of visually significant elevation of intraocular pressures.