October 6, 2011
Mucous layer (mucin) issues in dry eyes: role of goblet cells
Goblet cells generally low in dry eyes
Conjunctival goblet cell density in normal subjects and in dry eye syndromes. by R A Ralph Invest. Ophthalmol. Vis. Sci. April 1975 vol. 14 no. 4 299-302
Serial sections prepared from biopsies of the deep tarsal portion of the inferior nasal conjunctival fornix in normal subjects and in patients with various dry eye syndromes were analyzed with respect to the goblet cell densities. When compared to normal subjects, individuals with keratitis sicca, Stevens-Johnson syndrome, ocular pemphigoid, and acute alkali burn all demonstrated progressively lower goblet cell densities per millimeter of epithelial surface. These disease entities can, therefore, be considered goblet cell-deficient syndromes. [Full Text]
there is increasingly recognition of the importance of goblet cell density in many persistent dry eye cases. The clinical trials Gary Foulks did on Dakrina actually showed an increase in goblet cell density (I don't have the info handy but I believe this was a study on Sjogren's patients). Additionally I have heard from a few doctors who saw presentations by Allergan stating that Restasis is believed to increase goblet cell density. [Source]
Increased level of solvents in dry eyes can kill goblet cells
Increased tear osmolarity can potentially induce pathological changes, including loss of conjunctival goblet cells and desquamation of conjunctival epithelium, to the ocular surface [Source]
From TheraTears website:
The tears are a salt solution. As an eye becomes dry, the tears lose water and become too salty. And just like when you throw salt on a wound, it stings and burns when your tears become too salty, your eyes sting and burn, and later there is a sensation of dryness and sandy-gritty irritation.
Dry eye is a condition characterized by loss of water from the tear film. As a result the tear film becomes saltier and more concentrated. Most of us will remember “osmosis” from high school chemistry. When the tear film becomes too concentrated, osmosis pulls water out of the surface of the eye, making it dry.
In dry eye the high salt concentration in the tear film (the high "tear osmolarity" or hypertonicity) and the changes on the surface of the eye cause the stinging and burning, dryness and sandy-gritty irritation. And because evaporation from the eyes is greater when the eyes are open than when they are closed, the symptoms of dry eye get worse as the day goes on.
One of the most important changes that occur in dry eye is a reduction in the number of conjunctival goblet cells on the surface of the eye. You're probably wondering what a conjunctival goblet cell is. Did you ever wonder why your eyes don't squeak when you blink? It's because on the surface of the eye there are thousands of mucus-containing cells called "goblet cells." Mucus is the most slippery substance in the human body. Think of these goblet cells as the "ball bearings" of the eye surface — instead of containing stainless steel they contain mucus. And this is why normal eyes don't squeak when they blink and one of the reasons why dry eyes are so uncomfortable.
[Listen to Dr Gilbard of Thera Tears]
Less blinking can kill goblet cells
[Surgery] keeps the lids seperated) causes trauma to the conjunctiva. The conjunctiva is where most goblet cells are replenished. [Source]
THERA TEARS CAN HELP?
TheraTears (Advanced Vision Research). This hypotonic solution is designed to enhance tear volume and reduce the osmolarity of the tear film. Jeffrey Gilbard, M.D., who created TheraTears, suggests that "saturation dosing" with this product can diminish symptoms of dryness and help restore the normal physiology and health of the ocular surface. A study of post-LASIK patients demonstrated that prolonged therapy with TheraTears helped restore normal conjunctival goblet cell density, while treatment with a preservative-free control did not.
GEFARNATE: Regenerating goblet cells
Gefarnate stimulates goblet cell repopulation following an experimental wound to the tarsal conjunctiva in the dry eye rabbit. Toshida H, Nakata K, Hamano T, Nakamura M, Nguyen D, Beuerman R. [Source]
Gefarnate increases PAS positive cell density in rabbit conjunctiva, Br J Ophthalmol 1998;82:1320-1323
Effect of gefarnate on the ocular surface in squirrel monkeys. Toshida H, Nakata K, Hamano T, Nakamura M, Nguyen D, Beuerman RW. Cornea. 2002 Apr;21(3):292-9.
Get Gefarnate from cabbage
Cabbage contains potent substances in it such as amino acids, L-glutamine and Gefarnate. These substances help protect the lining of the digestive tract so the ulcers can heal and new ones can be prevented. They also help increase the mucus production in the stomach, which helps coat, and protect the ulcers that have already formed on the lining of the stomach so they do not become worse and have a chance to heal. The best way to get cabbage into your diet to help heal and treat your peptic ulcers is by eating 2 to 3 cups of raw cabbage a day with a salad or meal. If you do not, like eating raw cabbage, you can always drink a couple glasses of raw cabbage juice each day and that will do the trick as well. [Source]
It is possible that squeezing cabbage juice and applying to the eyes will help. Need to try.
Trefoil factor family peptide 3
Trefoil factor family peptide 3 at the ocular surface. A promising therapeutic candidate for patients with dry eye syndrome? by Schulze U, Sel S, Paulsen FP. Dev, Ophthalmol. 2010;45:1-11. Epub 2010 May 18. Department of Anatomy, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany. firstname.lastname@example.org
Dry eye syndrome is a widespread disease accompanied by discomfort and potential visual impairments. Basic causes are tear film instability, hyperosmolarity of the tear film, increased apoptosis as well as chronic inflammatory processes. During the last decades, our understanding of dry eye syndrome has considerably increased. However, the molecular mechanisms of the disease remain largely elusive. In this context, our group focuses on trefoil factor 3 (TFF3). Among other factors, TFF3 performs a broad variety of protective functions on surface epithelium. Its main function seems to be in enhancing wound healing by promoting a process called 'restitution'. Studies evaluating TFF3 properties and effects at the ocular surface using in vivo as well as in vitro models have revealed a pivotal role of TFF3 in corneal wound healing. Subsequent studies in osteoarthritic cartilage seem to draw a different picture of TFF3, which still needs further elucidation. This manuscript summarizes the findings concerning TFF3 in general and its role in the cornea as well as articular cartilage – two tissues which have some things in common. It also discusses the potential of TFF3 as a candidate therapeutic agent for the treatment of, for example, ocular surface disorders.
Ophthalmic compositions comprising trefoil factor family peptides
See this. "compositions comprising trefoil family factor peptides will be useful in preventing or treating dry eye by topical administration of the composition to eye of the patient."
Trefoil peptides promote restitution of wounded corneal epithelial cells.
Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
Is this relevant? http://www.osnsupersite.com/view.aspx?rid=88331