The Dopaminergic Neuronal System Regulates the Inflammatory Status of Mouse Lacrimal Glands in Dry Eye Disease

The role of temperament in evaluating the relationship between symptoms and signs in dry eye disease

OBJECTIVES

In this study, we aimed to evaluate the relationship between symptoms and objective findings and dry eye (DE) patients' personalities and levels of depression and anxiety.

METHODS

The study group consisted of 67 DE patients who presented to the ophthalmology clinic with symptoms of dry eye disease (DED) and were first diagnosed. Patients underwent a complete ophthalmologic examination, including tear-film break-up time (TBUT), Schirmer 1 and Ocular Surface Disease Index (OSDI). All subjects also completed the Temperament and Character Inventory (TCI), Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI).

RESULTS

No relationship was found for the Schirmer 1 Test and TBUT with psychological parameters or OSDI scores. When compared with the normal values for the Turkish population, sub-dimensions of temperament in DED; novelty seeking (NS) was significantly lower (P<0.001); harm avoidance (HA) (P=0.014), and persistence (P<0.001) were significantly higher. Significant positive correlation with HA and significant negative correlation with NS were found for the OSDI results. Furthermore, our mediation model revealed that anxiety mediated the effect of NS and HA on OSDI.

CONCLUSION

The significant association of temperament sub-dimensions with OSDI scores in the DED group may play a role in explaining the inconsistency between symptoms and signs. Professionals who care for DED should consider temperament sub-dimensions when they detect discordance between symptoms and signs.

Impact of Lacrimal Gland Extraction on the Contralateral Eye in an Animal Model for Dry Eye Disease

Purpose

Although there is still no consensus on the best animal model for dry eye disease research, a model based on lacrimal gland extraction (LGE) model is widely used. In this study, we aimed to investigate the histopathological changes taking place on the contralateral eye after unilateral LGE to determine whether it is useful as a control.

Methods

Seven-week-old male C57BL/6 mice were divided into naive control, environmental chamber model, and LGE groups. Corneal fluorescein staining was scored to quantify the severity of damage. Morphological changes in the cornea, conjunctiva, and lacrimal gland (LG) were determined by hematoxylin and eosin staining and compared to those on naive control animals.

Results

Compared to naive subjects, the unilateral LGE model showed enhanced corneal erosion scores and loss of conjunctival goblet cells, not only on the ipsilateral but also on the contralateral side. These changes in the ocular surface became more pronounced in a time-dependent manner. Furthermore, loss of LG acinar cells and leukocyte infiltration were detected in the contralateral LGs of the LGE model.

Conclusions

Considering the changes observed in the ocular surface and LGs, the contralateral side of the LGE model may not offer proper control conditions for the experimental comparison of the effects of dry eye disease in vivo. There may be regulatory feedback or crosstalk system between both eyes activated in response to LGE.

Dopamine, a co-regulatory component, bridges the central nervous system and the immune system

Dopamine (DA) is a crucial neurotransmitter that plays an important role in maintaining physiological function in human body. In the past, most studies focused on the relationship between the dopaminergic system and neurological-related diseases. However, it has been found recently that DA is an immunomodulatory mediator and many immune cells express dopamine receptors (DRs). Some immune cells can synthesize and secrete DA and then participate in regulating immune function. DRs agonists or antagonists can improve the dysfunction of immune system through classical G protein signaling pathways or other non-receptor-dependent pathways. This article will discuss the relationship between the dopaminergic system and the immune system. It will also review the use of DRs agonists or antagonists to treat chronic and acute inflammatory diseases and corresponding immunomodulatory mechanisms.