Doctor, I have a bright red spot on my eye! What caused it, is it dangerous and what do I do now (about a subconjunctival hemorrhage)?
Broken blood vessels are a commonplace problem all over our bodies - resulting in what we commonly call a bruise. Generally they are not dangerous (though like most things - they can range in cause and in degree.) In rare cases they can be dangerous - so always report them to your eye care provider and call at once if there is significant pain, if they appear in the context of an eye injury or recent eye surgery or are associated with any loss of vision.
Understanding why a blood vessel breaks in the thin, clear, membrane we call the conjunctiva, (what we call a subconjunctival hemorrhage), means also understanding the membrane and the blood vessels in it. There are also several main functions of this membrane that speak to the dry eye issue that don’t directly relate to broken blood vessels but are also key to how we approach overly dilated and breaking blood vessels.
This “saran wrap-like” membrane we call the conjunctiva is supposed to be smooth, moist, clear and “shrink-wrapped” over the underlying white part of the eye (sclera) and over the inner sides of the eyelids. This provides for a smooth, even, and effortless squeegee of the lids, as they go back and forth over the clear “window” (cornea) we see through. It contains cells and tiny glands that make the proteins and some of the moisture that forms the tears that wash over the cornea. It also acts as the “lymph node” of the eye, containing the important defense cells that protect our eyes from pollution, infection and cancers that could come from sun exposure. It is the job of the blood vessels to supply the red blood support for this membrane, so it can do all these jobs.
Irritation – from pollution, infection, injury, allergies, friction – and sadly, yes - DRYNESS – all conspire to create inflammation – our body’s reaction to irritation. This leads to dilation of the blood vessels so that they can deliver more support to the membrane (conjunctiva) – so it can better do its many jobs. This makes the eye look “red” (from the bigger blood vessels carrying the red blood). This pattern is typically red-pencil web-like, as opposed to the broader strokes of red from broken blood vessels. The larger the blood vessel when it breaks, the larger the broad strokes of red from these “hemorrhages” – creating visible bruising.
Without getting too deep into all the sources of inflammation, I can only touch on the many risk factors for breaking blood vessels in the conjunctiva and I’ll stay focused on the common dry eye-related issues. Friction is a common one, as lack of tears – and most frequently, lack of tear oils, leads to more “drag” over the membrane as it tries to “hug” the support underneath. This support over the white of the eye is a fibrous “glue” that functions a bit like living Velcro (Tenon’s tissue). Friction breaks down the fibers and their glue – so the membrane comes loose (conjunctivochalasis – spelled many ways - please see my earlier posts on this). These pleats and folds twist and turn with blinking or from finger rubbing – and the “shearing forces” tear at the blood vessels. The dryness leading up to this can lead to increasing dilation of the blood vessels – so when they tear open, they can spill more blood than thin ones. Anything that causes irritation will lead to inflammation and to growing larger, redder blood vessels (so they can better do their job of supporting the effort of healing, defending, and otherwise taking care of the health of our eyes).
When you apply “vasoconstrictors” (like Lumify, Visine for red eyes, or other eye whitening over the counter products), these drops cause the muscles in the blood vessels to “squeeze” and choke down the blood flow. Less blood means less redness – the point of the eye “whitener.” The longer-term problem with this is several fold:
- these drops themselves contain preservatives – the harsh, toxic chemicals designed to prevent green fuzzy stuff from growing inside the bottle you apply it with. This “hurts” the eye and triggers more inflammation.
- the “squeezing” of the muscles leads to muscle fatigue. When the muscles “relax” the vessels become bigger, because with relaxation of the squeezing muscles, the blood vessel dilates (and carries more blood) – so looks redder – causing a desire to use more of the drops.
- with sustained use, there is a more rapid “wearing off” (tachyphylaxis), so the ability of the drop to do its job becomes less. This leads to a cycle of drop applications where the only winner is the company selling you those drops.
To fight inflammation, we use “anti-inflammatories” – medicines designed to calm the defenses down and allow the blood vessels to return to a more normal state (I have more comprehensive, earlier posts on this). In a healthy eye, these vessels are so small as to be nearly invisible to the casual observer (hence the “white” eyes). The more irritated the eyes are, the redder they become and the stronger the “anti-inflammatory” medication needs to be to counteract the redness (and quite the eye down). Strongest anti-inflammatories are the steroids like difluprednate, prednisone and dexamethasone. Weakest are the Cyclosporine (Restasis, Cequa and the like) and Lifitegrast (Xiidra) groups as well as the non-steroidals similar to aspirin (Advil, Aleve and the like).
The problem with all of these is that unless you are also dealing with the source of inflammation (whatever irritation is triggering it), then this is a Band-Aid approach. As soon as you back off on the anti-inflammatory medication, then the redness tends to bounce right back. Cauterizing blood vessels is a stronger way to curb them – but again, unless you deal with what brought them along to be big, red, angry-looking vessels, then they tend to grow back with a vengeance (because now you’ve really irritated that surface by damaging it, and the blood vessels are what help it to heal).
Long-term use of steroids can thin membranes and blood vessels, making them more fragile. Anything that thins blood (including all aspirin-like products as well as a bevy of other prescriptive and over the counter supplements, medication and even foods and oils) will mean larger bruises and red spots, too.
Finding the undercurrent of irritation and dealing with it directly will usually lead to the best “cure” for redness. Sometimes this is an autoimmune problem. Sometimes it is an allergy or some chronic toxic exposure (like the preservatives in the whiteners – and sadly also the steroids. Fortunately, the cyclosporine and lifitegrast products do not). Sometimes it is from incomplete restoration of the tears and ongoing dryness. The total number of causes of inflammation is a very long list, best sorted out by your dry eye specialist and any team required to turn over every stone and leaf. This means that until every aspect of irritation leading to redness is addressed, then it is hard to effectively reduce that redness. As long as there is friction, irritation and inflammation, this is an uphill battle.
My next post will cover the “what to do’s” when these bruises happen on the white of your eye.