Post-operative Pain and other Concerns
Chat Highlights – March 6, 2013
Guest Speaker – Dr. Michael Pro
Lorraine Miller, Editor, Chat Topic Researcher
Moderator: Welcome to this evening’s chat. Tonight we are very pleased to have Dr. Michael Pro join us. Our topic will delve into “Post-operative Pain and other Concerns.”
Dr. Pro: Good evening, everyone.
P: During a trabeculectomy, what is done to minimize pain during the surgery and after?
Dr. Pro: That is a great question. There are several ways to ameliorate surgical pain. It was more common in the past to perform a retrobulbar block. This is an injection of medicine behind the eye. The advantage of this is that a retrobulbar usually provides complete anesthesia during the surgery. The disadvantage is that a retrobulbar block can cause transient double vision and can leave a bruise under the eye. More importantly, a retrobulbar block can risk a retrobulbar hemorrhage, which is bleeding behind the eye. This bleeding can be dangerous, and in extreme circumstances, can lead to loss of vision. Fortunately, a retrobulbar hemorrhage is rare.
Today, we often use local anesthesia to help with surgical pain. So, the prep is really important. The eye is dosed with anesthetics before the surgery in the form of drops or gels. Local anesthetics are also injected into the eye or in the subconjunctival space during the surgery. The anesthesiology team is crucially important as they provide IV sedation during the surgery to relax the patient and provide additional anesthesia as needed.
P: When do all the pain medications given during surgery wear off?
Dr. Pro: It depends on the agent used. In general, a retrobulbar block wears off in six to eight hours. Topical anesthetics wear off fairly quickly (20-30 minutes), and may need to be readministered during surgery.
P: Does the eyeball feel pain?
Dr. Pro: Yes. The surface of the eye is enervated by many sensitive nerve endings. The cornea is very sensitive to pain, as anybody would know who has suffered a corneal abrasion. We can feel tiny foreign bodies on the surface of the eye that you may never detect on another part of your body, like an eyelash in the eye. On the other hand, the internal structures of the eye can feel pain, but it is more of a visceral sensation that is poorly localized and more often can be characterized as a boring and deep ache.
P: For weeks after surgery, some experience a feeling of a quick, sharp, stabbing pain in the eye. Why would this occur?
Dr. Pro: I think it is due to post-operative inflammation and healing. As I said before, the internal structures of the eye localize pain poorly. I have heard this complaint many times. If the pain is very brief and the examination otherwise looks good, we often will recommend artificial tears as irregularities in the ocular surface and tear film are common after surgery and can also cause pain or ocular irritation.
P: I’ve tried Percocet, cold compresses and ketorolac drops for post Ahmed valve surgery pain relief. I have a very large, working (IOP 18-24) bleb due to severe keloid scarring which is being managed by 5-FU injections and one bleb revision. Do you have any suggestions on pain management?
Dr. Pro: I am sorry to hear about your pain. I am not sure how long post-op you are, but it is unusual to require Percocet to relieve pain, certainly after the first day or so. I would recommend that your glaucoma surgeon re-evaluate you to try to determine the cause for the pain.
P: The ketorolac slightly works, but not a dramatic improvement, and my eye throbs each night. Systemic NSAIDs are not advisable for me as I have irritable bowel. I am six months post-op. My specialist feels it is the keloid scar and the size of the bleb, which he does not want to shrink, as the bleb is doing a great job.
Dr. Pro: Yours is certainly a tough case and it sounds as though your doctor has tried all sorts of things.
P: I have one of the best in the country. He’s referred me to a pain management specialist. He also added a third drop of Alphagan to keep the bleb from getting grotesquely large by the evening. It’s better, but certainly not livable long term. I was hoping for a fresh perspective or idea.
Dr. Pro: Your doctor is a very respected glaucoma specialist. I know that he is very thoughtful and caring.
I cannot comment on specific recommendations as I have not examined your eye. Sometimes you or your surgeon may want to seek a second opinion from another local glaucoma surgeon.
P: Can a patient experience irritation from the ends of the stitches that were placed in the eye?
Dr. Pro: Absolutely. Many surgeons will use dissolvable sutures, but many will also use nylon, which may need to be removed at some point in the post-op period.
P: How would I know if the irritation I feel is from the stitches or something else?
Dr. Pro: That can be tough for the patient to know, but usually discomfort from a suture is fairly localized, whereas general ocular surface issues causes more diffuse discomfort. Also during an exam, your eye doctor will be able to see loose sutures.
P: Does the surgery cause the eye to be dry?
Dr. Pro: Yes, any intraocular surgery can worsen dry eye syndrome. Increased symptoms may last longer after glaucoma surgery due to the presence of a large bleb or conjunctival elevation from a tube, both of which can cause a disturbance in the tear film that covers the eye.
P: Do the post surgical medications also cause dry eye?
Dr. Pro: Yes, they certainly can, as can may glaucoma drops. We have discussed the issue of dry eyes in glaucoma in the past. The issue is sometimes the preservative in the drops, but sometimes the medication itself can disrupt the normal tear film.
P: If post-operative eye irritation does not lessen as time progresses, what could be the problem?
Dr. Pro: Well, sometimes the presence of a large and overhanging bleb can cause a focal area of corneal dryness that can be tough to moisten even with a preventive application of artificial tears. In some cases, a revision of the bleb may be needed to reduce the bleb height or excise tissue that is draping the cornea.
P: Since surgery years ago, my eyelid is always swollen at the lashes after I am in a prone position. Why would this happen?
Dr. Pro: It could be due to dependent edema. Surgery may have caused lid swelling and ruptured the fine connective tissue attachments in the eye. Now there may be less resistance to fluid accumulating in the lid when you are prone.
P: When blinking the eye after surgery, sometimes a popping or clicking sound could be heard. Why does this occur?
Dr. Pro: Probably due to a small air pocket that get trapped under the lid. It might also be the bleb or conjunctival elevation from the tube allows this air to collect between the lid and the eye.
P: Some eyes seem to ooze fluid for no reason months after surgery. What could cause the feeling of the eye unexpectedly filling up with liquid?
Dr. Pro: It is probably due to dry eye. The eye is irritated and reflex tearing can cause this to happen.
P: What is the difference between a bleb revision and needling?
Dr. Pro: A bleb revision can mean many things, encompassing something simple like a bleb needling to a more involved surgery where the conjunctiva is incised and the bleb is completely revised with additional sutures.
P: Even after a year post surgery, my eye is sensitive to light. Why am I having problems with light sensitivity?
Dr. Pro: This is complaint that I often hear. Of course, I have not inspected your eye. Sometimes the problem is dry eye. Sometimes glaucoma surgery can affect the integrity of the iris and allow more diffuse light into the eye. Sometimes a cataract is the problem, or even an artificial lens. The easiest simple first step is to use artificial tears and see if your symptoms improve.
Moderator: Dr Pro, thank you once again for taking the time to answer questions. It is much appreciated.
Dr. Pro: Thanks, everyone. Good night.