Choroidal thickness was greater in ERM eyes with than without VMT possibly due to direct anteroposterior traction on the retina and choroid, increased vascular endothelial growth factor associated with stress on retinal pigment epithelial cells and inflammation. After vitrectomy, mean SFCT reduced in the eyes with VMT, but not in those without VMT.

This paper presents a system-of-systems (SoS) approach to the formal modeling of a cyber-physical system (CPS) for simulation-based analysis. The approach is based on a convergence technology for modeling and simulation of a highly complex system in which SoS modeling methodology, hybrid systems modeling theory, and simulation interoperation technology are merged. The methodology maps each constituent system of a CPS to a disparate model of either continuous or discrete types. The theory employs two formalisms for modeling of the two model types with formal specification of interfaces between them. Finally, the technology adapts a simulation bus called DEVS BUS whose protocol synchronizes time and exchange messages between subsystems simulation. Benefits of the approach include reusability of simulation models and environments, and simulation-based analysis of subsystems of a CPS in an inter-relational manner.

PurposeTo evaluate the prognostic factors and outcomes of dexamethasone intravitreal implant (DEX implant) for intravitreal bevacizumab refractory macular edema secondary to branch retinal vein occlusion (BRVO).MethodsThis was a retrospective, interventional case series. Medical records were reviewed, and a total of 38 eyes that were treated with DEX implant for macular edema secondary to BRVO that did not respond to at least two consecutive intravitreal bevacizumab injections (IBIs) were included. Best-corrected visual acuity (BCVA), central subfield macular thickness, and central subfoveal choroidal thickness were evaluated at baseline, 2 months, and 6 months after DEX implantation.ResultsPatients had undergone an average of 6.32 ± 4.66 prior IBI treatments. The average BCVA improved from 0.53 ± 0.26 to 0.41 ± 0.25 and 0.44 ± 0.23 logarithm of the minimal angle of resolution (logMAR) at 2 and 6 months, respectively (p < 0.001). The average central subfield macular thickness was 504.00 ± 121.54 µm at baseline and changed to 293.21 ± 74.17 µm and 427.28 ± 119.57 µm at 2 and 6 months, respectively (p < 0.001 and p = 0.002). Average central subfoveal choroidal thickness was 237.46 ± 92.21 µm at baseline and changed to 204.75 ± 74.74 µm and 226.86 ± 90.77 µm at 2 and 6 months, respectively (p < 0.001 and p = 0.455). Twenty-two eyes (58%) gained ≥0.1 logMAR at 2 months, while 16 eyes showed no improvement. Low BCVA at symptom presentation, low baseline BCVA, and shorter duration of macular edema were correlated with increased BCVA after treatment.ConclusionsThe DEX implant improves functional and anatomical outcomes for up to 6 months in about half of the patients treated with IBI refractory macular edema secondary to BRVO, particularly in patients with low initial and baseline BCVA.

PurposeTo investigate the peripapillary choroidal thickness (PCT) of polypoidal choroidal vasculopathy (PCV) and exudative age-related macular degeneration (AMD) and to evaluate their responses to anti-vascular endothelial growth factor (VEGF).MethodsThirty eyes with PCV and 25 eyes with exudative AMD who were treatment naïve were included in this study. PCT and subfoveal choroidal thickness were evaluated both before and after intravitreal anti-VEGF.ResultsThe initial mean PCT of PCV (153.78 ± 56.23 µm) was thicker than that of exudative AMD (88.77 ± 23.11 µm, p < 0.001). Temporal, superior, nasal, and inferior PCTs of PCV were all thicker than those observedin exudative AMD (all p < 0.05). After anti-VEGF, the mean PCT of PCV was significantly reduced (134.17 ± 41.66 µm, p < 0.001), but the same was not true not in exudative AMD (86.87 ± 22.54 µm, p = 0.392). PCTshowed a similar tendency in all quadrants.ConclusionsPCV exhibits a thick choroid in the peripapillary region. PCT decreases after anti-VEGF in PCV but not in exudative AMD. In exudative AMD, subfoveal choroidal thickness decreased, but that in the peripapillary region did not.

This report describes a case of angiographically documented foveal avascular zone (FAZ) enlargement after a single intravitreal injection of bevacizumab for macular edema secondary to central retinal vein occlusion (CRVO). A 71-year-old female was treated with an intravitreal bevacizumab injection for macular edema following CRVO. Despite successfully decreased edema one month after injection, the postinjection best-corrected visual acuity immediately decreased from 20/40 to 20/1000 (Snellen equivalent). The FAZ area increased from 0.37 mm2 to 3.11 mm2 (8.4-fold increase). While intravitreal anti-vascular endothelial growth factor is effective and should be considered as a first-line treatment for macular edema secondary to CRVO, it may aggravate macular ischemia.