CME With Different Fluidic Parameters

June 5, 2012 updated by: Abhay R. Vasavada, Iladevi Cataract and IOL Research Center

Impact of Different Fluidic Parameters on Development of Cystoid Macular Edema Following Phacoemulsification

Understanding and modulating fluid parameters is an important, but often overlooked aspect of phacoemulsification. In a previous study we compared the impact of using high fluid parameters versus low fluidic parameters on real-time IOP measured during phacoemulsification. The investigators found that using high parameters resulted in a higher absolute rise in IOP as well as higher fluctuations in the IOP when compared to low parameters. Clinically these higher fluctuations in IOP would translate in a higher chamber instability. Based on the results of this study, the investigators decided to take it further and study the impact of using high parameters (and thus, higher chamber instability) on macular edema and thickness following surgery, in an otherwise uncomplicated surgery.

Higher fluid parameters during phacoemulsification predisposes the eye to increased macular thickness

Study Overview

Detailed Description

Several studies have shown the adverse impact of an increase in the IOP and IOP fluctuations that occur during anterior segment intervention on the posterior segment structures. In human volunteers with each incremental increase in IOP the systolic and diastolic flow velocities in the short posterior ciliary arteries decreased linearly. This implies that the normal healthy eye is not able to autoregulate to maintain posterior ciliary artery blood flow velocities in response to acute large elevations in IOP. Vascular insufficiency due to abnormal autoregulation has been proposed as a major factor in the development of glaucoma. 1

It has been postulated that IOP elevation during the LASIK procedure causes mechanical stress which may induce tangential stress on the posterior segment.2, 3 Some studies have reported that the increase in IOP damages the retinal ganglion cells causing visual field defects. Also sudden increases in IOP, although well tolerated may induce changes in the peripheral retina.4,5,6

Several reports propose the occurrence of macular hole, lacquer cracks and choroidal neovascular membranes following the LASIK procedure. 3 It has been observed that the rapidly fluctuating pressure variations may be detrimental, particularly in susceptible persons with compromised ocular blood flow. Rapid IOP changes across a 30-mm Hg range would be predicted to influence posterior segment blood vessels.

In a previous study we compared the impact of using high fluid parameters versus low fluidic parameters on real-time IOP measured during phacoemulsification. We found that using high parameters resulted in a higher absolute rise in IOP as well as higher fluctuations in the IOP when compared to low parameters. Clinically these higher fluctuations in IOP would translate in a higher chamber instability.

We hypothesize that although transient, the increased IOP that occurs during phacoemulsification when using high parameters could cause mechanical stress on the eye. These higher fluid parameters during phacoemulsification can predispose the eye to increased macular thickness.

To the best of our knowledge there are no published data on impact of IOP changes and fluctuation that are induced during cataract surgery on the macula. To investigate this further, we decided to study the impact of using high parameters (and thus, higher chamber instability) on macular thickness following surgery, in an otherwise uncomplicated surgery.

Study Type

Interventional

Enrollment (Actual)

150

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Gujarat
      • Ahmedabad, Gujarat, India, 380013
        • Raghudeep Eye Clinic

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

40 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Uncomplicated, Age-related cataract.
  2. Nuclear sclerosis: upto grade 3
  3. Age: 40-70 years
  4. Axial length: 21.5 mm to 24.5 mm

Exclusion Criteria:

  1. Diabetes mellitus
  2. Co-existing ocular disease- uveitis, glaucoma, PEX
  3. Pre-existing macular pathology (eg.ARMD)
  4. Previously operated eyes
  5. Under treatment with Topical or systemic steroids / NSAID's
  6. Intraoperative complications- PCR, Descemet's detachment, uveal trauma
  7. Post operative complications - severe inflammation (>grade 3), rise in IOP

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Longitudinal U/S - low fluidic
ASPIRATION FLOW RATE - 25 CC/MIN, BOTTLE HEIGHT - 90 CMS, LONGITUDINAL ULTRASOUND
conventional longitudinal ultrasound
Other Names:
  • phacoemulsification
  • small incision cataract surgery
Active Comparator: Torsional U/S - low fluidic
ASPIRATION FLOW RATE - 25 CC/MIN, BOTTLE HEIGHT - 90 CMS, TORSIONAL ULTRASOUND
conventional longitudinal ultrasound
Other Names:
  • phacoemulsification
  • small incision cataract surgery
Active Comparator: Longitudinal U/S - high fluidic
ASPIRATION FLOW RATE - 40 CC/MIN, BOTTLE HEIGHT - 110 CMS, LONGITUDINAL ULTRASOUND
conventional longitudinal ultrasound
Other Names:
  • phacoemulsification
  • small incision cataract surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
cystoid macular edema (CME)
Time Frame: 3 months
A > or = 30% increase in baseline central foveal thickness measaured by anterior segment OCT will be defined as having CME.
3 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
macular thickness
Time Frame: 1, 3 months
macular thickness measured in 3 zones using the anterior segment OCT
1, 3 months
central corneal thickness (CCT)
Time Frame: first post-operative day,
CCT will be measured on the ultrasound pachymeter by a single experienced observer
first post-operative day,
endothelial cell loss
Time Frame: 6 months post-operative
Endothelial cell loss will be measured using a specular microscope in the central area by a single technician
6 months post-operative
anterior chamber inflammation
Time Frame: 1 months
it will be assessed on the slit lamp examination by a single experienced observer using the Hogan's criteria
1 months
CORRECTED DISTANCE VISUAL ACUITY (CDVA)
Time Frame: 3 months
visual acuity (VA) of 20/40 or worse was defined as "clinically significant"
3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: ABHAY R VASAVADA, MS, FRCS, ILADEVI CATARACT AND RESEARCH CENTER

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

May 1, 2010

Primary Completion (Actual)

February 1, 2011

Study Completion (Actual)

August 1, 2011

Study Registration Dates

First Submitted

June 28, 2011

First Submitted That Met QC Criteria

June 29, 2011

First Posted (Estimate)

June 30, 2011

Study Record Updates

Last Update Posted (Estimate)

June 6, 2012

Last Update Submitted That Met QC Criteria

June 5, 2012

Last Verified

June 1, 2012

More Information

Terms related to this study

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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