Topical 0.1% Bromfenac Sodium and Prostaglandin E2 Inhibition in Cataract Surgery

Study Overview
=================
Brief Summary
-----------------
Since a new generation of femtosecond lasers became available for cataract surgery in 2009, the use of this image-guided system has provided several benefits, including a reduction in phacoemulsification energy by prefragmentation of the crystalline lens, and the potential advantages of more precise corneal incisions and capsulotomy formation. However, as with any new surgical technique, femtosecond laser cataract surgery also has potential complications. Intraoperative miosis is one of the most common intraoperative complications of femtosecond laser-assisted cataract surgery, with a reported prevalence ranging from 9.5 to 32.0%.8 Significant pupillary constriction necessitates the removal of the anterior capsule flap, fragmented nucleus and remaining cortex, which is potentially associated with a higher rate of surgery-related complications.

Detailed Description
-----------------
Since a new generation of femtosecond lasers became available for cataract surgery in 2009, the use of this image-guided system has provided several benefits, including a reduction in phacoemulsification energy by prefragmentation of the crystalline lens, and the potential advantages of more precise corneal incisions and capsulotomy formation. However, as with any new surgical technique, femtosecond laser cataract surgery also has potential complications. Intraoperative miosis is one of the most common intraoperative complications of femtosecond laser-assisted cataract surgery, with a reported prevalence ranging from 9.5 to 32.0%. Significant pupillary constriction necessitates the removal of the anterior capsule flap, fragmented nucleus and remaining cortex, which is potentially associated with a higher rate of surgery-related complications. Intraoperative miosis may be due to the intraocular effects that occur after femtosecond laser pretreatment. The intraocular tissues may be exposed to laser emissions, and lens proteins can be released into the anterior chamber. Together, these events trigger the release of unwanted cytokines. In a previous study, intraocular prostaglandin concentrations were found to be increased immediately after femtosecond laser pretreatment. Prostaglandins, especially prostaglandin E2 (PGE2), are known to play a role in inflammation-induced miosis. Preoperative topical treatment with NSAIDs inhibits the release of prostaglandins in response to surgically-induced miosis by suppressing cyclooxygenase, the enzyme that transforms arachidonic acid into prostaglandin precursors. The effectiveness of ophthalmic NSAIDs in preventing miosis has been well documented in conventional phacoemulsification cataract surgery. However, whether this effect is also applicable to femtosecond laser-assisted cataract surgery is unknown. Yeoh has suggested the addition of NSAID eye drops to the dilation regimen during femtosecond laser cataract surgery, but no randomized study has been conducted to support this theory. Given the increasing popularity of femtosecond laser-assisted cataract surgery, the investigators sought to study whether topical NSAIDs might be beneficial in pupil maintenance and PGE2 inhibition during the procedure.

Official Title
-----------------
Topical 0.1% Bromfenac Sodium for Intraoperative Pupil Dilation Maintenance and Prostaglandin E2 Inhibition in Femtosecond Laser-assisted Cataract Surgery

Conditions
-----------------
Cataract

Intervention / Treatment
-----------------
* Drug: 0.1% bromfenac ophthalmic solution
* Procedure: femtosecond laser cataract surgery


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: if they were 50 years of age or older and were scheduled to undergo femtosecond laser cataract surgery Exclusion Criteria: a previous history of intraocular surgery; recent trauma; uveitis; systemic disease, such as diabetes mellitus; hypertension; the use of systemic or topical NSAIDs within 1 week of enrollment.

Ages Eligible for Study
-----------------
Minimum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 0.1% bromfenac ophthalmic solution<br>Patients received 0.1% bromfenac ophthalmic solution twice a day for 3 days before surgery. | Drug: 0.1% bromfenac ophthalmic solution<br> <br> Procedure: femtosecond laser cataract surgery<br> <br> |
| Placebo Comparator: control physiological normal saline<br>Patients received control physiological normal saline twice a day for 3 days before surgery. | Procedure: femtosecond laser cataract surgery<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pupil area measured using ImageJ software A |  | surgery | 
| PGE2 levels measured with an enzyme-linked immunoassay |  | 2 days after surgery |