Therapeutic Insights
Managing Eye Pain
The role of over-the-counter and prescription analgesics in treating patients with ocular pain.
By Leland Carr, O.D., Forest Grove, Ore.

As clinicians, we've been trained to concentrate on treating eye injuries, infections and inflammations. We focus on differential diagnosis and appropriate selection of therapeutic agents. We carefully assess sight-threatening conditions and judiciously apply potent antibiotics and anti-inflammatories in our efforts to quiet the eye. Yet, we may have overlooked key elements of the patient's original complaint: "Doctor, my eye hurts . . . ."

Or worse yet, we may have missed a golden opportunity to use analgesics in a preventive fashion, thus leaving our patients wide-open for pain and discomfort that we could've predicted.

Keep their needs in mind

In caring for our patients, we should try to remember that they don't like to see poorly, appear sick and perhaps most importantly, they don't like to hurt or ache. This means that the true state-of-the-art clinician is comfortable and competent with using topical and systemic analgesics to combat and prevent eye-area pain.

Numerous conditions arise to cause patients pain. Injuries including lacerations, abrasions, erosions, ecchymosis, hyphema and orbital fractures all hurt. Infectious or sterile inflammations including corneal ulcers, zoster ophthalmicus, hordeolae, chalazia, iritis and acute intraocular pressure rise are also painful for most patients.

Additionally, we perform procedures that will predictably result in pain if we don't manage the patient appropriately. Examples here include corneal rust ring removals, anterior stromal punctures, punctal cauteries and skin lesion removals. It's easier to prevent pain than it is to play catch up.

Contraindications

Many over-the-counter (OTC) analgesics and some narcotic combinations contain aspirin, acetaminophen, ibuprofen or naproxen in varying levels. All of these ingredients pose certain risks to patients, so you need to take a thorough history to rule out contraindications prior to recommending or prescribing any of them.

If a patient is allergic to aspirin, it's a sure bet that she'll also be allergic to any of the nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen and naproxen.

Don't prescribe celecoxib to patients who report a known hypersensitivity to sulfa drugs. Avoid prescribing acetaminophen for those who have advanced liver disease because of the drug's well-known liver-toxic effects.

If a patient has a history of stomach or duodenal ulcers, consider all of the NSAIDs high risk. Even the latest generation NSAIDs, the so-called COX-2 inhibitors (celecoxib and rofecoxib), have been known to exacerbate digestive tract ulcers -- especially when used with any level of aspirin intake.

While definitely gentler on the stomach, even these new generation analgesics aren't without risk. This is especially true if you consider a patient who has failing or compromised kidneys.

Complications

NSAIDs can cause severe complications (such as an acute renal crisis) for patients who have kidney failure or advanced kidney damage from long-term problems such as diabetes. For similar physiologic reasons, you shouldn't use NSAIDs to treat eye pain in patients with severe dehydration.

An example of a disaster in the making is the 25-year duration hypertensive diabetic who is treated for angle-closure glaucoma with oral acetazolamide and oral glycerol, then given a stiff dose of ibuprofen or naproxen to counter the eye pain and headache that accompanies the acute ocular pressure.

Know your patient's body and eye health before selecting a medicine to treat a painful eye. Know his allergy history and pay close attention to a history that confirms or suggests problems with the stomach, the small intestine, the liver or the kidneys.

Another caution worth noting is the risk of bleeding associated with aspirin and all NSAIDs including the COX-2 inhibitors.

While most patients tolerate the anticoagulant effects of these drugs, and some drugs are weaker thinners than others, a patient already prone to bleeding because of medicines such as coumadin or heparin, needs full assessment before he's given additional blood thinners. Get a medical consultation and/or a blood clotting profile from the lab before selecting aspirin or aspirin-like analgesics for patients using anticoagulants.

Narcotic analgesics

Are there similar key points to emphasize for doctors prescribing narcotic analgesics? O.D.s in all states are now allowed to prescribe or recommend OTC pain relievers. Many states don't authorize O.D.s to prescribe schedule II, III or IV controlled substances, but there are some that do. See "Drug Schedules" on page 100 for a better understanding of the drugs included in each schedule. Drug Enforcement Agency (DEA) numbers are required to prescribe controlled substances.

An analgesic combination using ibuprofen or naproxen with acetaminophen provides good relief for many patients -- if there aren't systemic contraindications for the use of these products (i.e., stomach ulcers, liver disease or kidney disease). Yet for patients requiring potent pain relief, in cases where sedation and reduced activity is likely to aid healing, and in cases where the goal is to minimize drug-trauma to the gut, liver or kidney, narcotic analgesics are often the best way to go. While many do contain some level of aspirin or acetaminophen, the accumulated dose of those products tends to be less when they're contained within a narcotic analgesic.

Drug abuse warning

All narcotic analgesics do have abuse potential. Fortunately, most patients receiving short-term treatment for pain relief don't develop dependence syndromes. The longer the treatment, the greater the accumulated dose, the more doses provided in a single prescription without refill, and the more times the prescription is refilled -- the greater the risk that drug abuse is occurring. See "Indicators of Physical Dependence."

In general, a practical approach to managing eye pain involves prescribing analgesics with clear instructions to use them. A common mistake is to give instructions to "take the pain relievers if you need them," instead of "use the product as I've directed for the next 24 to 48 hours to help prevent your pain from getting out of control." If you can predict that eye pain is likely to persist or intensify, prescribe aggressively to avoid a worsening condition.

Include topical NSAIDs when pain stems from an ocular surface lesion. In virtually all cases, with the possible exception of bacterial or herpetic ulcers, a 24- to 36-hour course of diclofenac (Voltaren) or ketorolac (Acular) will act synergistically with oral analgesics in giving greater control over eye pain. In similar fashion, a conjunctival or lid wound will respond favorably to topically applied lidocaine in combination with an oral analgesic.

Finally, select your systemic analgesic based on accomplishing a simultaneous pain-relieving impact on the central nervous system and on the peripheral pain sensing nerves and organelles at the lesion.

Look before you prescribe

Take careful note of the patient's allergy history, health history and current drug use history. Pick the product most likely to effectively control the pain, while minimizing the risks of side effects, adverse reactions, drug interactions and dependency. 

DR. CARR IS DEAN OF THE COLLEGE OF OPTOMETRY AT PACIFIC UNIVERSITY, WHERE HE'S ALSO A CLINICAL PROFESSOR. HE'S TAUGHT NUMEROUS COURSES IN PRIMARY CARE, OCULAR DISEASE AND OCULAR PHARMACOLOGY. DR. CARR IS ALSO A CONSULTANT TO THE COUNCIL ON OPTOMETRIC EDUCATION OF THE AMERICAN OPTOMETRIC ASSOCIATION.

DR. CHRISTENSEN HAS A PARTNERSHIP PRACTICE IN MIDWEST CITY, OKLA. HE'S A DIPLOMATE IN THE CORNEA AND CONTACT LENS SECTION OF THE AMERICAN ACADEMIES OF PRACTICE.