What if there were eye drops for treating your macular degeneration? What if all you had to do was simply use a few drops a day and your vision would get better? There is a “solution” for tired eyes, redness, contact lenses, but what about for your retina?
Eye Drops for Macular Degeneration Sound Compelling
There aren’t any eye drops for macular degeneration or diabetic retinopathy. In fact there are few retinal diseases where they would work at all. Topical drops, just like intravitreal injections, however, are great because the medicine is placed directly where you want it – at the target tissue.
Drops, like eyeglasses, seem to be a panacea. No matter how carefully I explain the prognosis or treatment plan to a patient, I usually get a blank stare (and then I realize noone was listening to me) and then they say the inevitable…”What about eye drops?” or “What about Glasses?”
“Visine” – It Gets the Red Out
Maybe the reason eye drops are held so closely to everyone’s heart is due to “Visine®,” or at least the marketing department of Visine. Everyone knows that famous byline – “it gets the red out.”
A drop that gets red, tired eyes to look refreshed in seconds certainly would get my attention. If there are drops that get your eyes to change appearance, then there must be drops for everything else…right?
Most Drops Work Only on the Outside
There are ocular solutions for;
- allergy and itching
- dryness (artificial tears)
- dilating drops
- and for inflammation.
But there are no drops for macular degeneration or diabetic retinopathy for that matter. Eye drops are great for diseases that affect the outside of the eye. So called “topical therapy” typically does not penetrate the eye very well, and it is very difficult to get any significant concentration of drug into the vitreous or to the retina.
Outside of glaucoma, most drops are placed exactly where we want them, on the outside of the eye. Glaucoma drugs have become pretty good (so I’m told) at lowering the pressure inside the eye due to limited penetration of the glaucoma drug.
Most Drugs Never Get Inside the Eye
May be now this makes a bit more sense. Eye drops for macular degeneration sound great, but they just don’t exist. As far as we can tell, we have found the right drugs, but not in a form that has easy an easy time getting to the inside of the eye. Avastin®, Macugen® and Lucentis® are all too large for the molecules to penetrate the ocular surface. Steroids, such as Kenalog® or related anti-inflammatory agents, have poor surface penetration, too. All these drugs, if given as topical eye drops, would simply splash on your eye and run down your cheek…wasted.
What Does This Mean? My comments a few weeks ago about the blood brain barrier and the treatment of retinal disease left out any remarks about topical treatments. Eye drops are great for diseases on the outside of the eye. Just as intravitreal injections are working well for retinal disease due to targeted delivery, so too are eye drops. They are delivered directly to the target issue.
In eye disease, we do have to split hairs. There are vast differences between the outside and inside of the eye. The method we choose to deliver the drugs depends upon what, and where, you are treating.