Rare Optic Neuropathy in a Jamaican Couple Linked to Cassava Root Consumption.

We report central visual loss with selective papillomacular bundle damage in a Jamaican couple, husband and wife, with long-term cassava root consumption. The two cases presented independently with gradual central visual loss. Examination revealed bilateral temporal pallor of the optic nerve head and automated static perimetry demonstrated a central or caecocentral scotoma in each patient. Optical coherence tomography findings are described. The only mutual risk factor, reported independently, was long-term cassava consumption. Cessation of cassava intake and vitamin supplementation resulted in partial recovery of visual function. As thiocyanate levels in urine were not measured, the aetiology in these patients is not definitively confirmed, but chronic cassava consumption should be considered in similar cases as a rare cause of potentially reversible optic neuropathy.

Defective erythroid differentiation in miR-451 mutant mice mediated by 14-3-3zeta.

Erythrocyte formation occurs throughout life in response to cytokine signaling. We show that microRNA-451 (miR-451) regulates erythropoiesis in vivo. Mice lacking miR-451 display a reduction in hematrocrit, an erythroid differentiation defect, and ineffective erythropoiesis in response to oxidative stress. 14-3-3zeta, an intracellular regulator of cytokine signaling that is repressed by miR-451, is up-regulated in miR-451(-/-) erythroblasts, and inhibition of 14-3-3zeta rescues their differentiation defect. These findings reveal an essential role of 14-3-3zeta as a mediator of the proerythroid differentiation actions of miR-451, and highlight the therapeutic potential of miR-451 inhibitors.

A Novel Surgical Approach for Oculodermal Melanocytosis: Superficial Sclerectomy.

OBJECTIVE: To report the outcomes of a new surgical method for oculodermal melanocytosis (nevus of Ota)-superficial scleral separation. METHODS: Twenty-five eyes of 25 patients with scleral pigmentation arising from oculodermal melanocysis. These patients underwent superficial scleral separation between March 2012 and February 2013. Each patient was evaluated with the followings: ocular examinations, the preoperative extent of scleral involvement of nevus of Ota, satisfaction score after surgery, histologic examination, and postoperative complications. Main outcome measures were best-corrected visual acuity (BCVA), induced refractive error, intraocular pressure (IOP), patient satisfaction scores, and anterior segment photographs. RESULTS: All patients showed cosmetic improvement without any serious complications. Preoperative and postoperative BCVA, IOP, and refractive outcomes did not change significantly. CONCLUSIONS: Superficial scleral separation is an effective procedure for cosmetic improvement of oculodermal melanocytosis.

Cytokines regulating hematopoietic stem cell function.

PURPOSE OF REVIEW: Regulation of the multiple fates of hematopoietic stem cells - including quiescence, self-renewal, differentiation, apoptosis, and mobilization from the niche - requires the cooperative actions of several cytokines and other hormones that bind to receptors on these cells. In this review we discuss recent advances in the identification of novel hematopoietic stem cell supportive cytokines and the mechanisms by which they control hematopoietic stem cell fate decisions. RECENT FINDINGS: Several extrinsic factors that stimulate ex-vivo expansion of hematopoietic stem cells were recently identified by a number of experimental approaches, including forward genetic screening and transcriptional profiling of supportive stromal cells. Recent experiments in which multiple cytokine signaling pathways are activated or suppressed in hematopoietic stem cells reveal the complexity of signal transduction and cell-fate choice in hematopoietic stem cells in vivo and in vitro. SUMMARY: The study of genetically modified mice and improvements in the in-vitro hematopoietic stem cell culture system will be powerful tools to elucidate the functions of cytokines that regulate hematopoietic stem cell function. These will further reveal the complex nature of the mechanisms by which extrinsic factors regulate signal transduction and cell-fate decisions of hematopoietic stem cells.

Occipital tip injury with homonymous central scotoma: OCT-NFL and RGC correlation.

PURPOSE: To report one case of homonymous paracentral scotoma with corresponding optical coherence tomography (OCT) findings in a young woman after injury to the left occipital lobe tip. OBSERVATIONS: A young woman with past medical history of Hodgkin's lymphoma and large B-cell lymphoma metastatic to the left occipital lobe status post resection presented to the eye clinic with a chief complaint of a "blind spot" in the right eye since her surgery. Humphrey visual field (HVF) showed a right homonymous paracentral scotoma corresponding to the non-decussating and decussating optic radiation for central vision originating from the left lateral geniculate nucleus (LGN). OCT confirmed atrophy of the right nasal hemifovea with fibers originating from the papillomacular bundle and the left temporal hemifovea with fibers originating from the superior temporal segment of the optic nerve. These fibers correspond to the central vision involved with the left posterior occipital lobe tip. CONCLUSIONS AND IMPORTANCE: We report a case of right homonymous central vision loss as a result of injury to the left posterior occipital lobe tip with certain unique features. Here, a small lesion in the posterior visual pathway led to a relatively large loss of ganglion cell layer.