Optimal Method for Mydriasis in Cataract Surgery

Recent research has compared the use of intracameral and topical agents with the preoperative
pupil size and cataract surgery success. Studies have compared topical mydriatics with
intracameral lidocaine and found no significant difference in dilation. , Other studies have
compared topical mydriatics with intracameral dilation that includes solutions with and
without epinephrine in the irrigating solution and concluded that irrigating solutions
without epinephrine can safely be used with intracameral mydriatics but epinephrine is useful
when using topical mydriatics. There have also been studies comparing the success of longer
acting drug inserts of mydriatic agents with the use of intracameral agents. In addition to
these standard agents, different surgeons have used various formulations of topical and
intracameral agents to perform mydriasis. As of yet, there is no formal, standardized method
for mydriasis and no large prospective study comparing the outcomes of the various methods.
Considerations such as cost and time spent on preoperative mydriatic agents in light of the
amount of success seen with these agents calls into question the need for such agents. The
investigators would like to study the amount of pupillary dilation seen with topical
preoperative mydriatic agents compared to intracameral agents compared to the use of them
both together.

This will be a prospective randomized controlled trial. Patients will be consented and
enrolled at their pre-op visit. They will be randomized to topical drops alone, intracameral
injection alone, or topical plus intracameral mydriasis. All patients will receive
intracameral lidocaine, as this is used for its anesthetic effect but also has some mydriatic
effect. The intervention will take place on the day of the operation. Patients will be
followed until post-operative month #1.

Data will be gathered on 4 visits: pre-op clinic visit, day of operation, and post-operative
day #1 and post-operative month #1. These are all standard visits for routine cataract
surgery, and this study will not require the patient to make any extra visits. Enrollment
will continue until the sample size is met.

Patients cannot be blinded to whether or not they receive topical mydriasis eyedrops, and no
placebo drops are necessary because patients cannot voluntarily control their pupillary
constriction, so no placebo effect would be expected. The surgeon cannot be blinded to
whether or not the patient has received topical mydriasis eyedrops in the pre-op area because
it will be evident based upon whether or not the patient's eye is dilated. Another researcher
who was not present in the operating room will grade the photographs and measure the pupil
size, and this researcher will be blinded to which intervention the patient received.

Currently, some surgeons use topical plus intracameral mydriasis for mydriasis during
cataract surgery. It is hypothesized that intracameral mydriasis alone may be sufficient to
adequately dilate the pupil for cataract surgery. Patients who are not adequately dilated at
the time of pupil size measurement immediately before the capsulorrhexis step will
subsequently receive additional pharmacologic mydriasis, visco-dilation, or iris expansion
devices to dilate their pupil to a size that is adequate for their surgery. Therefore, no
matter which group the patient is in, their pupil will be eventually dilated to a size that
is adequate to proceed with surgery.

There is no placebo or non-treatment group, since all patients must be somehow dilated in
order to undergo cataract surgery. The purpose of this study is to compare 3 methods of
dilation.

The pupil size will be measured after the viscoelastic is injected and before the
capsulorrhexis is performed. Treatment failure is defined as a pupil size that is clinically
deemed too small to safely proceed with surgery (approximately less than 5 mm). At this
point, a rescue intervention will be implemented with additional pharmacologic mydriasis,
visco-dilation, or iris expansion devices, until the pupil is adequately dilated to proceed
with surgery. These patients will still be included in the study, and their pupil size prior
to the rescue intervention is still the primary outcome.

Participants can choose to stop participating in the study prior to receiving any of the
mydriasis agents. Should they choose to withdraw from the study, they would end up receiving
routine mydriasis with topical plus intracameral agents. The study ends on post-op month #1
for all individual patients. The study enrollment period will end when the sample size is
met.

Inclusion Criteria:

Patients aged 40 or older who are undergoing routine cataract surgery under topical
anesthesia with monitored anesthesia care at the Wilmer Eye Institute with Dr. Fasika
Woreta and her senior resident proficient at cataract surgery.

Exclusion Criteria:

- Need for general anesthesia

- Maximum pupillary dilation <6.0mm at the pre-op clinic visit.

- Prior intra-ocular surgery

- Prior trauma

- Any pre-existing iris abnormalities including pupillary deformity, posterior
synechiae, peripheral anterior synechiae, zonular dehiscence

- Pseudoexfoliation

- Allergy to any of the mydriasis agents

- Pregnancy or breastfeeding