Treating evaporative dry eye and blepharitis with petrolatum next to the eye

Warning and disclaimer

Theoretical background

• The tear film has three layers.
  • Next to the eyeball is a mucin layer.
  • Atop that is an aqueous layer (tears).
  • Floating on that is a lipid (fatty, oily) layer, which acts to prevent evaporation of the aqueous layer.
• In Sjogren's Syndrome, dry eye results from deficiencies both in the tear film and the lipid layer. That is, the problem is not only that Sjogren's patients make insufficient tears, but that their lipid layer is inadequate, and therefore tears evaporate faster than they should.
• The lipid layer is normally secreted by the meibomian glands through tiny openings in the eyelid margins. For reasons not well understood, in Sjogren's Syndrome the meibomian glands frequently malfunction, clogging up with overly thick, hard lipid blockages, and sometimes itching. The resulting condition is known as blepharitis.
• Donald MacKeen, PhD (an SSF board member) has discovered that if petrolatum is placed next to the eye, some of it will gradually migrate into the eye in a time-release fashion. He calls this movement "supracutaneous".
• A 1999 study published in the British Journal of Ophthalmology, New treatment of dry eye: the effect of calcium ointment through eyelid skin delivery, by Tsubota K, Monden Y, Yagi Y, Goto E, Shimmura S
  • measured MacKeen's supracutaneous effect, and found it to begin within ten minutes of application, peak at 30 minutes, and taper down to 20% of peak after about three hours.
  • found petrolatum next to the eye to be effective in reducing evaporation rate and blink rates in patients.
  • found a petrolatum-based calcium carbonate ointment to be more effective than plain petrolatum in reducing corneal staining.

Practical method -- one person's experience

• During daytime, I apply a moderate amount of petrolatum to both upper and lower eyelids, using a cleaned finger or a cotton tip applicator. I smear it from the outer corner of the eye across upper and lower lids, just outside the lashes. The amount I am using now is about the size of two large grains of rice, per eye. This is roughly double the amount used in the Tsubota study cited above, in which the ointment was applied only to the lower lid.
• Another user reports that he gets a cosmetically preferable result by applying to only the upper eyelid, for less of a weepy look.
• I wipe off the petrolatum (with facial or toilet tissue) and reapply fresh when it seems to lose its effectiveness, which is normally at roughly one to three hour intervals.
• At bedtime, I use about three times as much petrolatum, again on lower and upper lids, and I cover the eyes with clear plastic wrap and an eyeshade.
• I found petrolatum for sale in a tube marked "100% pure petroleum jelly" and "White petrolatum, USP". In the United States, Vaseline is a popular brand of petrolatum. Note though that most products with the Vaseline brand are NOT pure petrolatum, and would be inadvisable for use near the eye.
• I use a dedicated tube of petrolatum for my next-to-eye purpose, in order to keep it clean.

Results reported by one person

• Subjectively, I find the petrolatum markedly reduces the burning sensation. This in turn reduces reflex tearing.
• I find much less need for artificial tears.
• I find that I no longer need to wear goggles all day.
• My ophthalmologist can now get a clear (not cloudy) fluid out of my meibomian glands by squeezing them during an examination. When I only treated the lower lid, only the lower-lid meibomian glands looked good by this measure. When I changed to treating both upper and lower lids, both lower- and upper-lid meibomian glands yielded the nice clear stuff.
• I apparently no longer need to use the other measures I had previously been taking to combat blepharitis (meibomian gland dysfunction):
  • warm compresses for 10 minutes per day
  • doxycycline 100mg/day
  My lid hygiene routine now is just a brief wipe with warm wet washcloth, and a wipe of the lid margin.
• Appearance-wise, I do look a little bit shiny around the eyes -- but not totally bizarre I think. Definitely less bizarre than goggles.

Frequently asked questions

Q:Could I apply a nighttime ointment next to my eye and get the same results?
A:I have tried that and have found it is less effective than pure petrolatum. I think the reason is that the mineral oil that is added to the nighttime ointments make it spread too fast and too thinly to be effective when applied next to the eye.

Q:Aren't you worried about using petrolatum that is not labeled "sterile"?
A:If I could find a source for sterile petrolatum I would use it. Since I have not found that yet, I take comfort in the fact that fats and oils don't support microbe populations in the way that aqueous solutions do.

Further detailed thoughts and speculations

• If the anecdotal reports of good meibomian gland functioning hold true, then we have to wonder about the mechanism by which this treament helps keep the meibomian glands working right. Some possiblities I have come up with are:
  • Perhaps the petrolatum creeps down into the meibomian gland openings and directly acts as a "thinner", thus keeping the meibomian gland ducts from clogging.
  • Perhaps the petrolatum works by slowing evaporation, thus breaking the vicious cycle in which dry eye leads to blepharitis which leads to dry eye.
• On the question "Will we ever know if this is safe and effective?"
  • because petrolatum is unpatentable, cheap, and widely available, there is no financial incentive for investors to fund a clinical trial to establish that it is safe and effective for dry eye. Unless a nonprofit or governmental agency conducts a study, then at best we will get evidence of this method's safety and efficacy when it is used, as it was in the Tsubota study mentioned above, as the control in a study.
  • Donald MacKeen has patented the use of petrolatum-based preparations as a time-release mechanism for delivering drugs to the eye. I think this holds great promise, and that it may attract some funding for studies of various drugs delivered in this way. Those studies should give further information about the long-term safety of using petrolatum next to the eye (although they may be carried out on non-dry-eye populations and therefore may have nothing to say about effectivenss for dry eye).
• What is the mechanism for supracutaneous movement of petrolatum?
  • MacKeen's patent application suggests it has something to do with a scissoring action during blinking. I don't think this is true.
  • What I have seen suggests to me that the petrolatum creeps in all directions from where it is placed on the skin, and will creep between the lashes and across the eyelid margin and into the eye. Of course it also creeps down onto the cheeks and up toward the eyebrows, where it does no good and no harm. It appears to also creep up the lashes and off the ends of them, where it forms dangling threads of petrolatum.
  • These observations beg the further question, what causes the creeping? I don't have an answer to that. Whatever it is, the creeping is stronger than gravity; if you put a dot of petrolatum on your cheek and then wait half an hour, the cheek gets shiny not only below but also above the dot.
  • I did hear by email from the roommate of a physicist, who wrote that the physicist said this was a well understood phenomenon of fluid dynamics. The physicist explained it to my correspondent as follows: " you've got some more solid petrolatum floating atop some less solid petrolatum (the warmer part next to your skin) and the more solid bit will skid off in *all* directions till it's all distributed in a thin layer of less solid stuff, At which point we feel the need to reapply as its not moving as much." This would explain why the petrolatum seems less effective if it's warm and liquid (as for example when it's been sitting in a hot car). It would also explain why I get more mileage out of petrolatum than out of petrolatum thinned with mineral oil, as is found in commercial preparations meant to be put into the eye for nighttime use.