More About Dry Eye and Glaucoma (spotlight on Durysta)
Dry eye and glaucoma - they often go together, hand in hand. Partly this may mirror the age groups affected (though younger ages are increasingly more affected by dry eye and less by glaucoma - it is also true that as we age, incidence of both will rise). I covered a general discussion of this earlier (see my earlier link and more information, below).
What is glaucoma? Technically, vision comes from the capture of light, conversion of that light to electrical energy, the transfer of that energy to our brain and the “unscrambling” of that electronic signal to form a mental image. Simply, it is easier to explain by thinking back to the pre-cable television era. Before cable TV, there were antennas that were perched on our rooftops - or else existed as “rabbit ears” on top of our TV sets. They would capture the signals beamed from TV stations and convert that energy into electricity that was delivered to the back of TV sets by wires covered in brown plastic insulation. The plastic was scrapped off so the copper wire strands would be wound around little screws in the back of the TV to make a connection. Those of us who lived through that time might recall a time when, no matter what you did with the “tuning” of the antenna (remember swiveling the “rabbit ears” or wrapping them in tinfoil?), and no matter what you did with the tuning dial on the TV set itself, you couldn’t get a clear picture (or sometimes any picture) until you realized that the wires of your antenna had frayed or come loose and you had to freshen up the connection to get a clear picture. That is the essence of glaucoma, except we can’t freshen that connection or reconnect what is lost - once the “wires” (which are really tiny cells) are lost - we can’t get them back. The poor picture will only get worse - until all of the wires (and picture) are gone. That is glaucoma - and that is why we must work to prevent that outcome.
The “problem” is that we are all born with about one million “wires” (or cell fibers) per eye - and we can lose 4,000-5,000/year just through “normal wear and tear.” That implies that if any of us live long enough, we could all die blind. In reality, this would mean we would have to live hundreds of years to lose all of our vision - and since none of us live that long (yet), we don’t generally have to worry about that. Glaucoma happens when these fibers “fray” or die-off faster than normal. This can occur from genetic causes (smaller, less substantial nerves or more fragile nerves), from trauma (head or eye injuries) or from the multitude of issues that can cause increased pressure inside the eye. What eye doctors have learned is that if we can lower eye pressure enough, we can slow down this loss of fibers and preserve the nerve’s function (though we can never completely stop the natural process of some loss - just slow it down enough that we can prevent people from dying blind or visually disabled from glaucoma). The bigger problem is that we are all living longer - so eye doctors feel a greater need to diagnose - and to more aggressively treat - glaucoma to save our patients from dying blind.
Eye pressure (known as “IntraOcular Pressure” or IOP) is the result of the difference of how much “water” is made in the eye and how much of this “water” can leave the eye - think plumbing. In our eyes we have living cells - and like every living cell in our bodies, these cells need support. Where most of our living cells get their support from blood, the cells inside the front of our eyes con’t have blood - so they have a clear, water-like solution called aqueous humor (and the cells on the outer surface of our eyes have tears) for support. Simply put, the cells take what they need to survive from this “water” (called aqueous humor) and then put their “waste” into it. This “dirty, used up water” then needs to leave our eye. It does so by way of a filtered drain. The “waste” (pigments, proteins and cellular debris) gets deposited into the cheesecloth-like filter and the pure water returns to our circulation. As quickly as this “water” is made, circulates, and does its job, it then needs to leave they eye. If the filter clogs or there is a relative blockage anywhere in the “plumbing system” then the water backs up and causes pressure - until that pressure overcomes the blockage so the water can leave.
As a dry eye specialist who also sees glaucoma patients, my general recommended protocol was communicated in my earlier blog post, here: https://www.eyethera.com/blog/dry-eye-cataract-and-glaucoma-segment I continue to advocate for SLT, Durysta and less preserved, IOP-reducing eye drops (including the combined products that can deliver two medications in one drop). My experience with the Durysta glaucoma medication implant has grown since then, and I find it can be a great tool for getting more medication off of the eye’s surface and into the eye (where it needs to be, in order to do the work needed by lowering IOP).
Of interest, is the way the so-called Prostaglandin Analogs (PGAs) like Durysta (as well as the topical versions such as Latanoprost, Travoprost and Bimatoprost) work. Using my analogies and a fundamental understanding of evolution, I surmise that back in our cave-people-origin days, if our eyes got whacked in hunting, gathering or defending our clan - the response to a damaged eye (and damaged internal drain) could be a loss of sight from the pressure backing up inside the eye as it healed. Poor vision (or no vision) could lead to less procreation and extinction. Evolution came up with a hormone-like chemical our bodies can manufacture (prostaglandins or PGs) which can open a “pressure-relief-valve” inside the eye, that can send the internal watery fluid around the clogged or damaged drain and into a “special drain” (so-called uveoscleral outflow, for those who want to be in the know). As the eye heals, it makes less of this prostaglandin (PG) compound. Scientists discovered a way to create chemicals that act like our own PGs (so called Prostaglandin Analogs or PGAs). When they find their way into the eye, they open the same “pressure relief valve” and drop IOP as long as we use the drop (or have the implant working).
Typical drop-forms of PGAs contain preservatives (intentionally toxic chemicals designed to prevent germs or green fuzzy stuff from growing in the dropper and then getting on our eyes) - but now those preservatives can damage the cells that make our tears - and damage the cells served by those tears - so there is a love-hate relationship with these preserved medications. Durysta (and some newer PGA drops) is/are preservative free. Any IOP controlling chemical added to the surface of our eye as a drop, is going to “wash away” whatever tear was there - and has to “sit” long enough on the surface, to penetrate into the eye and do its job in there. Durysta is placed (quickly and painlessly) inside the eye - so there is no competition with tears, nor any toxic effect on the surface (it sits inside and gradually dissolves. Once dissolved, it most often will keep the “pressure relief valve “stuck open” for some months before that valve gradually closes and another implant is needed). It is important to make sure a PGA is indicated for IOP control and that there is no PGA allergy or expected unwanted side effects (every medication can have some and it is up to the doctor who would place it, to also consider when and if to place it - and then counsel you to help you decide if it is right for you). Glaucoma can be a complicated disease to diagnose and to manage, (as is dry eye disease) so having an experienced doctor help you with those decisions is critical to getting the best help.
More information on Durysta can be found here: https://www.durysta.com/
To schedule an appointment with Dr. Jaccoma, call Excellent Vision at either of these two dry eye offices:
(1) 155 Griffin Rd, Portsmouth, NH 03801 (603) 574-2020
(2) 3 Woodland Rd, STE 112 Stoneham, MA 02180 (near Boston) (781) 321-6463