ABDHISH R. BHAVSAR, MD
In this issue, we will explore the controversial
subject of intravitreal injection technique. There are a number of different
methods for administering intravitreal injections. Some controversial areas include:
the use of sterile drapes and gloves, the use of topical vs subconjunctival anesthesia,
and use of a lid speculum.
we are not recommending any particular treatment for your patients, this column
will be a nice exercise in exploring pro and con aspects of treatment decisions
that we face daily. This column should be interpreted in the spirit of a debate
society. I hope that you will find the column interesting, entertaining, and
THREE TOPICS WILL BE EXPLORED IN THIS
1. The use of sterile gloves and drapes during intravitreal injections
2. Topical vs subconjunctival anesthesia
3. The use of a lid speculum during intravitreal injections
Sterile Gloves and Drapes During Intravitreal
performing intraocular injections, I am of the opinion that everything should
be done to minimize risk. In my practice, I accomplish this by utilizing a full
sterile prep, drape, lid speculum, and sterile gloves such as I would in surgery.
Additionally, I administer antibiotic drops (oflaxacin or moxifloxacin). It is hard
to assess the incremental risk reduction of adding any of the procedure steps. However,
I think that Eyetech's VISION trial's reduction in endophthalmitis after changing,
or improving, the intraocular injection procedure suggests that technique does matter.
If the risk of endophthalmitis is approximately 1 in 1000, then it is almost impossible
for any given practitioner to tell if their technique is better, the same, or worse
compared to any other technique.
When in doubt, err on the side of patient safety. The only consideration
is the best interest of the patient. The patient's emotional, socioeconomic, and
real cost of vision loss from endophthalmitis outweighs any small incremental cost
of the slightly more complex procedure.
Nicholas Zakov, MD, FACS: In
my opinion, sterile drapes and sterile gloves play a very small part in decreasing
the risk of endophthalmitis during intravitreal injection. Key steps to avoiding
complications when administering intravitreal injections are to use betadine on
the cornea, conjunctiva, and lid margins, and to have a sterile needle enter the
globe. Betadine produces a clean, but not necessarily sterile, external environment,
not dissimilar to what is achieved in the OR during a "sterile" surgical procedure.
Informally, we have not seen an increased endophthalmitis rate
by abandoning the use of sterile drapes and gloves when administering intravitreal
injections in the manner described above.
vs Subconjunctival Anesthesia for Intravitreal Injections
IN FAVOR OF
I. Maguire, MD: With
any therapy, and its delivery, we look for effect, safety, convenience, cost, and
patient comfort and satisfaction. In the delivery of intravitreal pharmacologic
agents, topical anesthesia with 2% lidocaine gel delivers. Both topical and
subconjunctival pre-intravitreal injection of anesthesia is effective. However,
I feel topical anesthetic application is superior for the following reasons:
Anytime an additional needle is in proximity to the eye, risk of inadvertent globe
perforation is a small risk, but a risk nonetheless.
Convenience. Application of topical agents on a cotton swab
pledget is fast and easy.
Cost. A sterile swab is less expensive than a disposable syringe.
Patient Satisfaction. Beyond the clinical effects of an intraocular
injection, patient satisfaction is dependent on the comfort of the injection and
post-injection cosmesis. Topical anesthesia provides superior comfort. In addition,
conjunctival and episcleral vessels are better visualized and avoided, reducing
risk of post-injection subconjunctival hemorrhage. A normal feeling and appearing
eye is important to patients, especially when injections may be a monthly event
for an indefinite period.
IN FAVOR OF SUBCONJUNCTIVAL
A. Warren, MD: The
proliferation of pharmacologic advances for the treatment of retinal disease and
the need for intravitreal delivery of these drugs has given us the opportunity to
debate over the method of anesthesia that is most effective for delivery of these
Subconjunctival injection is clearly a more effective and safe
method for patients undergoing intravitreal injection when compared to topical application.
The goal of anesthesia is pain control and subconjunctival injection provides a
higher and more consistent level of drug to the ciliary body, which is the intended
target site. Topical anesthesia delivers less drug due to variability in absorption
of the drug through the conjunctiva. My observation has been one of inconsistent
pain control with the application of topical anesthesia, but uniform pain control
with subconjunctival injection.
In addition to reliable pain control, subconjunctival
anesthesia is safer. It is not as toxic to the epithelium as topical lidocaine and
is not a potential reservoir for
bacteria as is viscous lidocaine, thereby reducing
the risk of infection.
While topical anesthesia is certainly quicker, if your goal is
consistent pain control and safety, subconjunctival injection is your best bet.
of a Lid Speculum During Intravitreal Injections
M. Marcus, MD: Endophthalmitis
is the major vision-threatening complication from intravitreal injections. The VISION
study with Macugen alerted the retinal community to the need for meticulous sterile
technique and use of a lid speculum to significantly reduce the endophthalmitis
rate in patients undergoing repeated intravitreal injections. The key to endophthalmitis
prophylaxis is to reduce the ability of normal periocular flora to gain entry into
the eye. The eye lashes and lid margins harbor much of this flora. Use of a lid
speculum decreases exposure of the lashes and lid margins to the entry site of intravitreal
We use the lid speculum for vitrectomy, scleral buckle, and cataract
surgery. Particularly in light of the VISION study data, why would anyone not use
a lid speculum for intravitreal injections?
While there are a number of retina specialists who do
not routinely use the lid speculum during intravitreal injections, we have been
unable to obtain a brief statement from any 1 physician. The typical reasons for
not using a lid speculum include greater patient comfort, less conjunctival irritation,
lower chance of corneal or conjunctival abrasion, and greater overall satisfaction
of the patient during the intravitreal injection experience.
If patients are queried about the most uncomfortable portion of
the intravitreal injection procedure, many may respond that the placement and removal
of the lid speculum is the most uncomfortable part of the entire procedure. However,
the use of the lid speculum serves to keep the lids and lashes out of the pathway
of the needle and helps to give appropriate surgical exposure to the injection site.
Due to the potential risk of endophthalmitis and the potential risk reduction of
using a speculum,
it is understandable that the con position would be imprudent.
Although many years ago I tried performing intravitreal injections
without using a lid speculum, I do not feel comfortable doing these injections without
it, and always use a lid speculum during intravitreal injections.
Abdhish R. Bhavsar, MD, is an attending retina
surgeon at the Phillips Eye Institute, director of clinical research at the Retina
Center, P.A., in Minneapolis, Minn, and adjunct assistant professor at the University
of Minnesota. He also serves as state chair of the Minnesota Diabetes Eye Exam Initiative.
E-mail him about Face Off at
Retinal Physician, Issue: July 2006