Oxytocin is a neuropeptide widely recognized for its role in regulating social and reproductive behavior. Increasing evidence from animal models suggests that oxytocin also modulates reward circuitry in non-social contexts, but evidence in humans is lacking. Here we examined the effects of oxytocin administration on reward circuit function in 18 healthy men as they performed a monetary incentive task. The blood oxygenation level dependent (BOLD) signal was measured using functional magnetic resonance imaging in the context of a randomized, double-blind, placebo-controlled, crossover trial of intranasal oxytocin. We found that oxytocin increases the BOLD signal in the midbrain (substantia nigra and ventral tegmental area) during the late phase of the hemodynamic response to incentive stimuli. Oxytocin’s effects on midbrain responses correlated positively with its effects on positive emotional state. We did not detect an effect of oxytocin on responses in the nucleus accumbens. Whole-brain analyses revealed that oxytocin attenuated medial prefrontal cortical deactivation specifically during anticipation of loss. Our findings demonstrate that intranasal administration of oxytocin modulates human midbrain and medial prefrontal function during motivated behavior. These findings suggest that endogenous oxytocin is a neurochemical mediator of reward behaviors in humans – even in a non-social context – and that the oxytocinergic system is a potential target of pharmacotherapy for psychiatric disorders that involve dysfunction of reward circuitry.

Thyroid eye disease is an inflammatory orbitopathy associated with Graves disease. Vitamin D is a known immune system regulator. The authors show that vitamin D deficiency is associated with the development of thyroid eye disease. Purpose: Thyroid eye disease (TED) is an inflammatory orbitopathy with significant impact on visual function and quality of life. Although studies have shown that patients who are deficient in vitamin D are more likely to develop autoimmune conditions, there are no studies demonstrating a definitive correlation between serum 25-hydroxyvitamin D (25(OH)D) deficiency and an increased risk of TED. Methods: This retrospective case–control study compared serum 25(OH)D levels among 4 groups: 1) Graves disease (GD) patients with TED (n = 89); 2) GD patients without TED (n = 89); and healthy control patients matched to 3) the TED group (n = 356); and 4) the GD group (n = 356). The authors compared 25(OH)D level in the TED group measured within 1 year of TED diagnosis to the most recently measured 25(OH)D level in the GD group using Student t test of the log transformation of serum levels. Linear regression was used to control for other risk factors. Thyroid eye disease patients and GD patients were compared separately to their matched healthy control patients with linear mixed models. Results: Thyroid eye disease patients displayed significantly lower serum 25(OH)D levels than GD patients (24.8 ± 13.2 ng/ml vs. 29.4 ± 13.3 ng/ml; p = 0.006). Controlling for smoking status and previous radioactive iodine treatment did not affect this statistically significant difference. Conclusions: Low serum vitamin D is associated with TED diagnosis. Assessing and supplementing vitamin D levels may be an important addition to the early management of GD patients. Future research should include longitudinal studies and prospective clinical trials to further explore the mechanism responsible for the observed association.

Purpose: To test whether intraoperative stereotactic navigation during orbital decompression surgery resulted in quantifiable surgical benefit. Methods: This retrospective cohort study examined all consecutive patients who underwent primary orbital decompression surgery for thyroid associated orbitopathy performed by a single surgeon (A.K.) during the periods of 2012–2014 (non-navigated), and 2017–2018 (navigated). The study was HIPAA-compliant, was approved by the Institutional Review Board, and adhered to the tenets of the Helsinki declaration. Recorded parameters included patient age, sex, race, decompression technique (side of operation and walls decompressed), estimated blood loss (EBL), intraoperative complications, times that patient entered and exited the operating room (OR), times of surgical incision and dressing completion, pre- and postoperative best corrected visual acuity (BCVA), proptosis, diplopia, postoperative change in strabismus deviation, and need for subsequent strabismus surgery. Recorded times were used to calculate operating time (initial incision to dressing) and maintenance time (time between OR entry and initial incision and time between dressings and OR exit). The total maintenance time was averaged over total number of operations. Student t test was used to compare surgical times, maintenance times, EBL, and proptosis reduction. Fisher exact test was used to compare BCVA change, strabismus deviation change, resolution or onset of diplopia, and need for corrective strabismus surgery. Results: Twenty-two patients underwent primary orbital decompression surgery without navigation, and 23 patients underwent navigation-guided primary orbital decompression surgery. There were no intraoperative complications in either group. The average operative time was shorter in the navigated group for a unilateral balanced decompression (n = 10 vs. 19; 125.8 ± 13.6 vs. 141.3 ± 19.4 min; p-value = 0.019), and a unilateral lateral wall only decompression (n = 13 vs. 3; 80.5 ± 12.8 vs. 93.0 ± 6.1 min; p-value = 0.041). The average maintenance time per surgery was not significantly different between the non-navigated group (51.3 ± 12.7 min) and the navigated group (50.5 ± 6.4 min). There was no significant difference between the navigated and non-navigated groups in average EBL per surgery. There was no significant difference in BCVA change. Average proptosis reduction was larger in the navigated group, but this was not significant. There was a significantly lower proportion of patients who required corrective strabismus surgery following decompression in the navigated group than in the non-navigated group (39.1% vs. 77.3%, p-value = 0.012). Conclusions: Intraoperative stereotactic navigation during orbital decompression surgery has the potential to provide the surgeon with superior spatial awareness to improve patient outcomes. This study found that use of intraoperative navigation reduced operative time (even without factoring in a resident teaching component) while also reducing the need for subsequent strabismus surgery. This study is limited by its size but illustrates that use of intraoperative navigation guidance has substantive benefits in orbital decompression surgery.

BACKGROUND: As lasers have become an increasingly important component of commercial, industrial, military, and medical applications, reported incidents of non-therapeutic laser eye injuries have increased. The retina is particularly vulnerable due to the focusing power and optical transparency of the eye. Continued innovations in laser technology will likely mean that lasers will play an increasingly important and ubiquitous role throughout the world. Critical evaluation should thus be paid to ensure that non-therapeutic injuries are minimized, recognized, and treated appropriately. METHODS: A comprehensive literature review on the PubMed database was conducted to present case reports and case series representative of the variety of laser eye injuries in different injury circumstances, tissue types, and biological damage mechanisms. RESULTS: A general summary of non-therapeutic laser retina injuries is presented, including information about growth of the industry, increasingly accessible online markets, inconsistent international regulation, laser classifications, laser wavelengths, and laser power, mechanisms of tissue injury, and a demonstration of the variety of settings in which injury may occur. Finally, 68 cases found in the literature are summarized to illustrate the presentations and outcomes of these patients. CONCLUSIONS: As non-therapeutic laser eye injuries increase in frequency, there is a greater need for public health, policy, diagnosis, and treatment of these types of injuries.

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Purpose: Congenital ptosis can threaten visual function and is usually treated with surgical correction. This study tests the hypothesis that congenital ptosis involves not only the levator muscle but also the orbital septum, which may tether the eyelid in the primary position. Methods: A retrospective chart review was performed on 30 patients (41 eyelids) with congenital ptosis who underwent surgical correction that included partial septum excision. Histologic analysis was performed by a masked pediatric pathologist, with grading of septal tissue disorganization and fibrosis based on standard histologic criteria. An independent comparison of histologic grading with clinical ptosis measures was then performed. Results: Fifteen eyelids demonstrated significant septal fibrosis, 19 were mild, and 7 were not fibrotic. Thirty-six eyelids demonstrated histologic disorganization. Mildly fibrotic eyelids were found to have reduced preoperative levator function than those that were not fibrotic (2.84 ± 1.92 vs. 9.57 ± 4.76 mm; p < 0.0001). Samples that demonstrated significant fibrosis were also found to have reduced preoperative levator function (4.67 ± 2.12 vs. 9.57 ± 4.76 mm; p = 0.0007). Histologically disorganized samples were also found to have a lower preoperative levator function (9.50 ± 6.04 vs. 3.99 ± 2.49; p = 0.0052). Conclusions: Orbital septae in patients with congenital ptosis demonstrate histologic disorganization and fibrosis. When decreased levator function is observed clinically, septal fibrosis and/or disorganization is likely present. These observations suggest that debulking the fibrotic septum during congenital ptosis surgery may improve outcomes by releasing the eyelid from its congenitally tethered position, improving eyelid elasticity.

The orbit displays unique vulnerability to inflammatory conditions. The most prevalent of these conditions, thyroid eye disease (TED), occurs in up to 50% of patients with Graves' disease (GD). Whereas the pathology of both TED and GD is driven by autoantibodies, it is unclear why symptoms manifest specifically in the orbit. METHODS. We performed retinoic acid treatment on both normal and TED patient-derived orbital fibroblasts (OFs) followed by mRNA and protein isolation, quantitative realtime polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay, RNA sequencing, and Western blot analyses. RESULTS. Both normal and TED patient-derived OFs display robust induction of monocyte chemoattractant protein 1 (MCP-1) upon retinoid treatment; TED OFs secrete significantly more MCP-1 than normal OFs. In addition, pretreatment of OFs with thiophenecarboxamide (TPCA-1) inhibits retinoid-induced MCP-1 induction, suggesting an NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells)-dependent mechanism. We also found that treatment with cholecalciferol (vitamin D 3) mitigates MCP-1 induction, likely because of competition between retinoic acid receptors (RARs) and vitamin D receptors (VDR) for their common binding partner retinoid nuclear receptors (RXRs). CONCLUSIONS. Retinoids that naturally accumulate in orbital adipose tissue can act on orbital fibroblasts to induce the expression of inflammation-associated genes. These data suggest a potential role for retinoids in sensitizing the orbit to inflammation.

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