Vitreoretinal Findings in Nonarteritic Ischemic Optic Neuropathy.

BACKGROUND: Although nonarteritic anterior ischemic optic neuropathy (NAION) is considered a disorder that primarily affects the optic nerve head, optical coherence tomography (OCT) shows peripapillary and foveal subretinal fluid associated with optic disc swelling from NAION. We sought to further evaluate retinal and vitreous changes in patients with NAION. METHODS: Patients diagnosed with NAION at the New England Eye Center between 2013 and 2017 were evaluated using OCT. The presence and distribution of subretinal fluid was analyzed. Evidence of other vitreoretinal changes, including vitreopapillary traction (VPT) and the presence of hyperreflective dots (HRD), were also determined. RESULTS: Twenty-five eyes from 20 patients who presented within 4 weeks of symptom onset were assessed. Peripapillary subretinal fluid was seen in 16 eyes (64%). Of those eyes, the subretinal fluid extended into the macula in 4 eyes (16%). Visual acuity improved in 2 of 4 eyes after subfoveal fluid resolution. Intraretinal cysts located in the peripapillary region were seen in 8 eyes (32%), HRD were noted in 11 (44.0%). There was no evidence of VPT. CONCLUSIONS: A substantial number of patients with NAION have subretinal fluid on OCT, consistent with prior reports. Resolution of subfoveal fluid may result in some recovery of visual acuity. Other retinal changes, such as intraretinal cysts and HRD, are present but have unclear implications. We did not find evidence of a primary role of VPT in the pathophysiology of NAION.

Vitiligo non-responding lesions to narrow band UVB have intriguing cellular and molecular abnormalities that may prevent epidermal repigmentation.

We have discovered that human vitiligo patients treated with narrow-band UVB (NBUVB) demonstrated localized resistance to repigmentation in skin sites characterized by distinct cellular and molecular pathways. Using immunostaining studies, discovery-stage RNA-Seq analysis, and confirmatory in situ hybridization, we analyzed paired biopsies collected from vitiligo lesions that did not repigment after 6 months of NBUVB treatment (non-responding) and compared them with repigmented (responding) lesions from the same patient. Non-responding lesions exhibited acanthotic epidermis, had low number of total, proliferative, and differentiated melanocyte (MC) populations, and increased number of senescent keratinocytes (KCs) and of cytotoxic CD8+ T cells as compared with responding lesions. The abnormal response in the non-responding lesions was driven by a dysregulated cAMP pathway and of upstream activator PDE4B, and of WNT/ß-catenin repigmentation pathway. Vitiligo-responding lesions expressed high levels of WNT10B ligand, a molecule that may prevent epidermal senescence induced by NBUVB, and that in cultured melanoblasts prevented the pro-melanogenic effect of α-MSH. Understanding the pathways that govern lack of NBUVB-induced vitiligo repigmentation has a great promise in guiding the development of new therapeutic strategies for vitiligo.

Phosphodiesterase-4 Inhibitors Increase Pigment Cell Proliferation and Melanization in Cultured Melanocytes and within a 3-Dimensional Skin Equivalent Model.

Vitiligo is a common chronic autoimmune disease characterized by white macules and patches of the skin, having a negative impact on patients' life and without any definitive cure at present. Identification of new compounds to reverse depigmentation is therefore a pressing need for this disease. The pharmacologic compounds phosphodiesterase-4 inhibitors (PDE4is) are small molecules with immunomodulatory properties used for treatment of inflammatory dermatoses. PDE4is have shown repigmentation effects in patients with vitiligo, in some case reports. We characterized the proliferative and melanogenic potential of 2 known PDE4is-crisaborole and roflumilast-and of a more recently designed compound, PF-07038124. We used 2 in vitro model systems-the primary human melanocyte culture and a 3-dimensional cocultured skin model (MelanoDerm)-with an exploratory testing platform composed of complementary assays (spectrophotometry, melanin and proliferation assays, immunostaining, Fontana-Masson staining, RT-qPCR, western blot, and whole-transcriptome RNA sequencing). We identified that treatment with PDE4is was associated with increased melanocyte proliferation and melanization in both in vitro models and with increase in the melanogenic genes and proteins expression in cultured melanocytes. These effects were found to be enhanced by addition of α-melanocyte-stimulating hormone. Our findings support the further evaluation of PDE4is with or without α-melanocyte-stimulating hormone agonists in vitiligo trials.