June 26, 2011
The causes of dry eyes/ eye strain and remedies to deal with the causes
Extreme (undescribable) pain
Dry eyes can be the most painful thing to have (because the cornea is saturated with nerve cells and when exposed directly to the air, these cells scream!). I've experienced a lot of pain in my life, but this one is the most extreme form of pain I've had paricularly since it is so chronic, and indescribable. For a discussion on the levels of pain one can get, see this blog post.
Dry eyes causes are often misdiagnosed, which leads to improper treatment and frustration. [Source]
Word document that analyses causes, symptoms, and remedies
Please download this document which contains most of my analysis in a clear tabular format.
Underlying causes of eyestrain
Many medications trigger dry eyes, most commonly antihistamines, codeine, decongestants, diuretics, morphine, oral contraceptives and even eye drops such as Visine and Murine. A detailed study of 16,862 patients who visited two Veterans Affairs eye clinics during a 5-year interval, it was found that [Source]
a) Antihistamines are a MAJOR cause: 22 percent of patients using antihistamines were diagnosed with dry eye, compared with 10% of non-users.
Sanjeev: In my case the eye strain/ dry eye problem arose DIRECTLY after I had taken the an extreme dose of antihistamines because of hay fever in 2010. This is related to the fact that I'm developing allergies as I grow older. I became allergic to prawns/shrimp/shell-fish about six years ago (2005 appx) at around 45 years of age. I also started developing strong hay fever response in the past few years. (The worst episode was in 2010 which lasted for over three months. For at least two months I took antihistamines virtually daily.) It would appear to me that my dry eyes clearly arose from these antihistamines. Significant computer work aggravated the problem.
b) Antidepressants (including anti-anxiety medications and anti-benign prostatic hyperplasia medications) are strongly associated with dry eye syndrome.
c) Iodine deficiency: Tear glands contain large amounts of iodine. Lack of iodine can cause dry eyes [Source] [e.g. within a week of taking a couple of drops of Lugol's formula, indeed my dry eyes cleared up and, lo and behold, my skin felt softer [Source]]. I have probably got some form of deficiency since over the past 10 years in Australia I haven't used much iodised salt. So I've now (since September 2011) started using iodised salt plus taking a multivitamin that contains iodised salt.
d) Testosterone deficiency: Testosterone regulates the expression of more than 1500 genes in the mouse meibomian gland which serves to stimulate lipid and fatty acid metabolism in the lubricating eye fluid. This has obviously something to do with ageing.
Other uncommon causes include conjunctivitis, neurological diseases, lacrimal gland disorders, injuries, and Sjogren’s syndrome (e.g. Venus William's case). Apparently the preservatives in eye drops can also aggravate dry eyes.
Dry eyes are (sometimes) associated with dryness of other mucous membranes, interior body surfaces such as joints and brittle nails. It also can be a sign of digestive imbalances or of more serious autoimmune diseases, such as rheumatoid arthritis, Sjogren's syndrome or lupus erythematosus. These diseases trigger an immune response generating lymphocytes that slowly destroy the cells responsible for tear production and secretion. As a result, tear volume decreases, cells in the conjunctiva decrease and corneal cells can be lost, creating dry spots. In Sjogren's syndrome, for instance, the entire lacrimal gland, responsible for 90 percent of tear production, may be destroyed by the invasion of inflammatory lymphocytes. [Source]
What can go wrong (proximal causes)
Many things can go wrong, as I've shown in this Word document. Basically one can have three types of defects in the tear system:
a) Defect in the mucous layer
b) Defect in the aqueous layer
c) Defect in the lipid (meibomian) layer [Evaporative dry eye]
There is a strong possibility of vicious cycles operating in the system (this is an excellent video, below, that covers all major causes of dry eyes). One thing is clear: once a SINGLE problem is encountered, other problems soon enter the picture.
Useful summary of cause (a lecture in PDF)
- Test for deficit of water later: Schirmer Test
- Test for deficit of lipid layer: Tear film breakup time (TFBUT) test
- Also see this: Rose bengal staining test
Here's a new test to identify the cause: I've not got to use it yet.
My self-diagnosis (the eye specialist I have seen didn't bother to investigate)
Many people who have dry eye symptoms are treated as though the cause is aqueous deficiency (artificial tear supplementation and punctal plugs), when in fact their primary problem is meibomian gland dysfunction MGD. Some researchers believe that up to 70% of chronic dry eye may actually be MGD, not "classic" dry eye. More broadly, nearly half of the subjects with dry eyes have MGD [Academic paper].
MGD reduces lipid production for the ocular surface, leading to tear evaporation and dry eye. Decreased tear production reduces the eye’s ability to flush bacteria from the lid margins, enabling bacteria to infect the meibomian glands and eyelash follicles, in turn further degrading the tear film.
In my case I'm almost certain that the defect is in the LIPID LAYER (meibomian gland dysfunction MGD). Given the association of my problem with anti-inflammatories drugs AND computer use, I propose the following pathway for the cause of the problem:
Step 1: Antihistamines helped to dry out my eyes by reducing tear flow. This must have reduced tear production from the Meibomian Glands.
Step 2: The continued "excessive" computer use during this period of medication and artificial drying out of the eyes must have further dried out the eyes.
Step 3: The dryness would have led not only to the pain that I experienced, but to an increase in bacteria in the eyes. The bacteria choked the Meibomian glands, exacerbating the problem. Some (hopefully not many) could well have died permanently.
Clue: what has worked well in my case, and what has not: The following things do seem to help me: (a) hot compress (b) honey (which is an anti-bacterial) and (c) aloe vera (which is anti-bacterial as well). Note also that I don't yet have any stringy/soapy material in my eyes. My eyelids look perfectly healthy. I don't have red eyes. I don't have any scaling on the eyelids. The pain levels can be very furious, and irritation/soreness is chronic.
I suspect that antibiotics coupled with hot compress and like treatment will be useful in my case. This video demonstrates that these glands can die off if not cleared as soon as possible.
1) Tear glands (meibomian) are blocked and inflamed, if not dead
a. Unblock the glands
- Hold this against the closed eye for about one minute or so (see figure One).
- Then, having liquefied the oils with this warming, press with one finger firmly on your cheek.
- Next, with the first-finger, press firmly on the lower lid, pushing upward to push the oil up into the tear film (see figure Two).
- Do this a few times over the entire lower eyelid, and then repeat for the upper eyelid.
- Repeat the entire procedure for the other eye.
- Do this initially once per day for one week. This will help to unclog the blocked glands.
- After the first week, doing this once or twice per week should help prevent the glands from becoming reblocked.
I have found that honey, aloe vera and triphala also assist in cleaning the glands.See this.
2) Tear glands aren't getting sufficient "input"
See this blog post for nutritional supplements. See also these blog posts:
- Background: Natural remedies
- Background: Chinese medicine for dry eyes
- Background: Ayurvedic remedies for dry eyes
3) Body toxins need cleansing more generally
It is possible that cleansing the body of toxins could help revive the tear ducts. The human body is very resilient. It is unlikely that tear ducts will go permanently dead. There HAS to be a way to revive them. "Oil pulling" might help – although I'm very sceptical about it (see this).