Dry eye disease and oxidative stress

Abstract

Dry eye, an age-related condition, is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance and tear film instability. Environmental factors are also often implicated in dry eye including exposure to pollutants, ultraviolet (UV) radiation and ozone as well as the chronic use of preserved eyedrops such as in the treatment of glaucoma. These factors increase oxidative stress and ocular surface inflammation. Here, we reviewed the cellular, animal and clinical studies that point to the role of oxidative stress in dry eye disease. The biomarkers used to indicate oxidative damage in ocular surface tissues include 8-hydroxy-2 deoxyguanosine (8-OHdG), 4-hydroxynonenal (HNE) and malondialdehyde (MDD). Antioxidative defences in the ocular surface occur in the form of tear proteins such as lactoferrin and S100A proteins, and enzymes such as superoxide dismutase (SOD), peroxidase, catalase and mitochondrial oxidative enzymes. An imbalance between the level of reactive oxygen species (ROS) and the action of protective enzymes will lead to oxidative damage, and possibly inflammation. A small number of interventional studies suggest that oxidative stress may be directly targeted in topical therapy of dry eye treatment. For example, in vitro studies suggest that L-carnitine and pterostilbene, a blueberry component may reduce oxidative stress, and in animal studies, alpha-lipoic acid (ALP) and selenoprotein P may be helpful. Examples of treatments used in clinical trials include vitamin B12 eyedrops and iodide iontophoresis. With recent emphasis on ageing medicine and preventive holistic health, as well as the role of environmental science, research on oxidative stress in the ocular surface is likely to have increasing impact in the coming years.

The prevalence of meibomian gland dysfunction, tear film and ocular surface parameters in an Austrian dry eye clinic population

“…; Craig et al. ; Pflugfelder & de Paiva ; Seen & Tong ). It is important to note that these groups are not strictly separated from each other and mixed forms occur (Horwath‐Winter et al.…”

“…Dry eye may be divided into two major pathogenetic categories. Either caused by a lack of tears (aqueous teardeficient dry eye, ATD) or by excessive evaporation (evaporative dry eye, EDE) often leading to a vicious inflammatory cycle, including the formation of reactive oxygen species (2007a; Baudouin et al 2017;Craig et al 2017;Pflugfelder & de Paiva 2017;Seen & Tong 2017). It is important to note that these groups are not strictly separated from each other and mixed forms occur (Horwath-Winter et al 2003;Lemp et al 2012).…”

Induction of DDIT4 Impairs Autophagy Through Oxidative Stress in Dry Eye

“…Previous studies have demonstrated that the overproduction of reactive oxygen species (ROS) under environmental stress plays a key role in DED development. 5,6 Excessive ROS can cause severe oxidative stress and induce human corneal epithelial cell (HCEC) damage by targeting DNA, proteins, and intracellular processes. [7][8][9][10] However, the ROS-related signaling pathways involved in susceptibility or resistance to cell death in DED have not been thoroughly investigated.…”

Prediction of potential drugs and targets based on meibomian gland dysfunction module classification to guide individualized treatment

“…Copper transporters significantly increased in patients with DED, suggesting that copper plays an important role in the pathology of DED. 27 Soria et al found that the changes of MGD proteome are related to oxidative stress and antiapoptotic process. While glutathione can regulate the expression of MGD protein and play a therapeutic role.…”