This week saw the publication of ELZA’s better pain management protocol in the Journal of Clinical Medicine, and represents a significant advance in the way pain is managed in the first few days after epi-off CXL and TransPRK.
The reason patients need to take painkiller eyedrops after these procedures is the fact that both involve the removal of some of the epithelial cells at the top of the cornea before the stroma – the layer beneath – is treated. The epithelial cells regrow in the days afterward, but during this period, unless patients take their prescribed pain management eyedrops, they can experience pain and inflammation. Nobody wants patients to be in pain, so we give patients the best painkilling eyedrops available.
If you have a headache, you might take an ibuprofen tablet to take the pain away. Ibuprofen is an example of a non-steroidal anti-inflammatory drug (NSAID) – it reduces the inflammation that is causing the pain. These drugs are great painkillers when taken as a pill, and it’s also a great painkiller when it is administered as an eyedrop to your eyes. However, there is a reason many refractive surgeons do not offer NSAID eyedrops after surgery: side effects. They can slow the speed at which the epithelial cells regrow, and in very rare occasions, can cause the formation of severe corneal ulcers known as corneal melts.
Two questions were asked by Prof. Hafezi and his co-authors. The first was: why? The second was, can we do anything about it? If we can safely use NSAIDs in the first few days after surgery, then we can give patients the best quality of pain relief possible.
To answer the first question, we had to look at how NSAID drugs work. The act by blocking an enzyme called cyclooxygenase, which converts molecules found in the membrane of every cell, called phospholipids, into molecules that cause inflammation, and therefore pain. However, this means that more phospholipids go down a different route: the 5-lipoxygenase pathway, and this results in the upregulation of enzymes – matrix metalloproteinases – that digest protein, which explains the potential risk of melting.
This reveals the answer to the second question: can we do something about it? Ideally, you would use a topical 5-lipoxygenase inhibitor at the same time as a NSAID – but no such drug exists. However, there is a class of drug that can inhibit both pathways: steroids. Empirically, combining NSAIDs with steroids should mean we can get great NSAID pain relief, without the NSAID drawbacks. This is what Jerry Tan and Shady Awwad proposed, and for many years, they have been using this regimen in their clinics to give patients better pain management after TransPRK or epi-off CXL surgery. What the ELZA Institute did was formally examine the outcomes of every patient that had received this pain protocol over a 7 year period, just to make sure that there was no indication of delayed epithelial cell healing, or worse, corneal melting, with this approach. And in 877 patients, that’s exactly what we found.
Click here to read the paper: