Three steps lead to painless injections

Apr 15, 2013

How proper anesthesia, timing, approach reduce pain and even risk of endophthalmitis requiring repeat injections

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Patients who require repeat treatment with intravitreal injections are usually most concerned about pain. Use of a three-step anesthesia process helps these patients be comfortable, from initial injection through repeat injections.

 

By Liz Meszaros; Reviewed by Antonio Capone Jr., MD

Auburn Hills, MI-For patients required to receive repeat intravitreal injections, alleviating concerns about pain-as well as their actual pain-is a matter of a few simple, well-timed steps in the application of anesthesia, and a well-thought out and executed injection approach to minimize possible complications, according to Antonio Capone Jr., MD.

“Many of your patients will engage in intravitreal therapy for years,” said Dr. Capone, professor of ophthalmology, Oakland University, William Beaumont Hospital School of Medicine, Auburn Hills, MI. “For many of them, their greatest anxiety relates to pain. For that reason, it’s important to make the procedure as painless as possible.

“This doesn’t take very much time, and with a quick three-step technique, most patients have a painless injection most of the time,” added Dr. Capone, who is also partner, Associated Retinal Consultants, Royal Oak, MI. “I have done injections without the subconjunctival step, and for many patients, injections are well tolerated. But I find that more of the patients will more consistently have a painless injection experience when all three steps are used.”

Patient preparation

Patients must be well prepared and informed before any ocular injections are done, Dr. Capone explained.

“The first thing that comes to the mind of a patient after he or she has been told he or she needs ocular injections is pain,” he said. “My typical explanation to the patient is that idea of an injection is painful, but the reality of the injection is not.”

Dr. Capone will verbally walk them through the process, explaining his three-step sequential anesthesia numbing process, with each step rendering the next step painless.

“The critical key is delivering on this painless process, because you’re going to have patients coming back for multiple injections,” Dr. Capone said. “If you garner their trust by walking them verbally through a painless injection process, and then deliver such a process, you have successfully engaged them as an ally in the injection procedure. They will be much more likely to continue the injection process with confidence.”

Three-step anesthesia

Dr. Capone begins with the patient resting in a reclining chair, as flat as possible. Using the inferotemporal quadrant of the eye for injections, he has the patient look up and in with the eye to be injected.

He uses a three-step anesthetic process that consists of first, application of a mild topical anesthetic, such as proparacaine hydrochloride ophthalmic solution (Alcaine, Alcon Laboratories). He waits 30 to 60 seconds, and then applies a stronger topical anesthetic, typically a 4% viscous lidocaine. After another 30 to 60 seconds, he injects a subconjunctival 2% lidocaine solution. He then preps the area of injection with topical betadine.

“Typically, 3 minutes after the subconjunctival injection, I can go ahead with the eye injection,” Dr. Capone said. “For the injection itself, I will typically engage conjunctiva with the needle and get the needle subconjunctival for 1-3 mm.”

He enters the sclera with a beveled incision, and then enters the eye.

“The purpose for the conjunctival tunneling and the beveling is to have a guarded wound to minimize vitreous prolapse,” he said.

Once he has finished, Dr. Capone typically massages the wound with a cotton swab dipped in betadine to assure that no vitreous wicking occurs.

“If I do have a wick, I will displace the conjunctiva and massage over the area of injection to bury the wick,” he said.

Total time for the procedure is short.

“My total prep time-from drops to injection-is just short of 4 minutes,” he said. “The majority of the waiting time is the anesthesia. It’s typically fairly short, and the chart work can be done in that interval.”

Proper equipment

Using the appropriate needle will also aid in helping patients experience a painless procedure, Dr. Capone continued.

“In the past, if the needle was dull, it made it harder to use the tunneling technique, particularly when it came to beveling the wound in the sclera,” he said. “It’s essentially the same technique I use for doing sutureless vitrectomy with the cannula systems.

“I displace the conjunctiva, then tunnel in the conjunctiva to a certain degree,” Dr. Capone said. “Then I bevel in the wound for the same reasons-you’re more likely to get good wound closure and a lower likelihood of vitreous wicking. It’s a maneuver done to minimize the risk of endophthalmitis. The vitreous wick increases this likelihood by provided a direct communication between the inner eye and the ocular surface.”

This technique was more difficult when the injection needle did not penetrate the sclera as cleanly as the new needle does, Dr. Capone added. He currently uses an approved dexamethasone intravitreal implant (Ozurdex, Allergan) for which the FDA has recently approved a new needle. This new needle was developed specifically based on feedback from retina specialists relative to the glide factor and penetration of the older needle. Like the previous needle, the new needle is still 22 gauge, but is manufactured by a different company and features a new coating.

“It is remarkable that the coating alone has made the needle glide through the sclera that much more effectively, because it plays like a needle that is much sharper,” Dr. Capone said. “It’s a very dramatic difference.”

Patient follow-up

Endophthalmitis is the greatest concern with all ocular injections, Dr. Capone noted. Post-injection, the staff informs patients of the signs and symptoms of this condition, and gives them an information sheet to take home. Dr. Capone does not use topical antibiotics post-injections.

Patients are informed about discomfort after the procedure and are encouraged to use artificial tears during the first 24-hour period to address minor surface irritation. They are also told that the day after the procedure, they should not have any meaningful discomfort and that the eye should feel better with each day. If there is a break from that pattern to any degree, or worsening of vision, they are told to contact the office.

“If they contact the office, we will talk them through their symptom complex, and decide whether they should come in,” he said. “We have a very low threshold for bringing patients into the office. We’d rather see 100 patients that had no real problems than try to keep any patient from coming who may have endophthalmitis.”

The second concern in these patients is IOP elevation, Dr. Capone continued.

“I routinely see patients 6 weeks after the injection to monitor pressures,” he said. “With each patient, I have a conversation about the pressure issue, and then typically, before initiating therapy if they are still phakic, we will discuss the cataractogenicity of intraocular steroids.”

His technicians will consent the patients, hand them the informational sheet that covers endophthalmitis, and Dr. Capone reviews it with them as well post-injection.

“The patients need to know what to expect from an uneventful-as well as eventful-post-injection course,” he said. “If you talk them through this-instead of just doing the injection and sending them on their way-you minimize the number of post-procedural phone calls, because patients anticipate the various problems that are minor, such as ocular surface discomfort or subconjunctival hemorrhage.

“I will warn them about the subconjunctival hemorrhage, and tell them that they will notice that they eye doesn’t look good, but it feels fine and vision is unaffected,” Dr. Capone said. “The hemorrhage will be cosmetically be more alarming than anything.”

Patients are warned that if they experience any changes in vision, discharge, photophobia, or pain, they should contact the office. The most common reasons patients will call into the office post-procedurally is surface discomfort caused by the pre-injection preparation.

Dr. Capone explained that he typically waits 12 weeks after the initial injection to repeat the initial treatment.

“If I see residual edema, I will shorten that interval to 10 weeks,” he concluded. “I gradually reduce the interval until from injection to injection, there is no edema.”

 

Antonio Capone Jr., MD

P: 218/288-2280

Dr. Capone has no financial disclosures.

 

 

Three-step anesthesia process

  • Apply a mild topical anesthetic, such as proparacaine hydrochloride ophthalmic solution (Alcaine, Alcon Laboratories).

  • Wait 30 to 60 seconds, and apply a stronger topical anesthetic, such as a 4% viscous lidocaine.

  • Wait another 30 to 60 seconds, and inject a subvconjunctival 2% lidocaine solution.

 

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