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Endothelial Cell Loss and Induced Astigmatism After Wound-directed and Wound-assisted IOL Injection

This study has been completed.
Information provided by:
University of North Carolina, Chapel Hill Identifier:
First received: November 29, 2010
Last updated: November 30, 2010
Last verified: November 2010
The purpose of this study is to determine if there is any difference in astigmatism (eye surface curvature) or corneal endothelial cell density (the inner cell lining of the eye surface) after two different methods for inserting a lens during cataract surgery.

Condition Intervention
Cataract Surgery
Procedure: Lens insertion during cataract surgery

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Endothelial Cell Loss and Surgically Induced Astigmatism After 2.2 mm Wound Assisted vs 2.4 mm Wound-Directed Clear Corneal Incisions for Intraocular Lens Insertion During Cataract Surgery

Resource links provided by NLM:

Further study details as provided by University of North Carolina, Chapel Hill:

Primary Outcome Measures:
  • Surgically induced astigmatism [ Time Frame: 1 month ]
    measured by topography at 1 month post operative visit

Secondary Outcome Measures:
  • Endothelial cell loss [ Time Frame: one month ]
    As measured by specular microscopy

  • Best corrected visual acuity [ Time Frame: one month ]
    By manifest refraction

  • Final incision size [ Time Frame: intraoperatively (day #0) ]
    measured with incision gauges before and after lens injection.

Enrollment: 72
Study Start Date: April 2010
Study Completion Date: November 2010
Primary Completion Date: November 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Wound-assisted lens injection
Wound-assisted lens injection is considered neither superior or inferior to wound-directed lens injection.
Procedure: Lens insertion during cataract surgery
After cataract removal during cataract surgery, a lens needs to be injected into the eye. Both arms are routinely used but different methods for injecting the lens.
Active Comparator: Wound-directed lens injection
Wound-directed lens injection is neither considered superior nor inferior to wound-assisted lens injection.
Procedure: Lens insertion during cataract surgery
After cataract removal during cataract surgery, a lens needs to be injected into the eye. Both arms are routinely used but different methods for injecting the lens.

Detailed Description:

Cataract surgery (removal of a cloudy lens) is currently performed through increasingly smaller incisions. Bimanual surgery, where two instruments are used to remove the lens, is performed through two 1.4 mm incisions. Typically, one of these incisions is enlarged to 2.2 or 2.4 mm in order that the IOL (artificial lens) can be inserted into the eye. Surgeons insert these lenses by placing a lens injector cartridge completely into the eye (wound-directed insertion) or by placing only the tip inside the incision (wound-assisted insertion). While wound-assisted insertion can be performed through slightly smaller incisions (2.2 mm versus 2.4 mm for wound-directed insertion), both methods of insertion cause some incision enlargement. There is some evidence that wound-assisted insertion can cause very short-term pressure within the eye to go up. Neither method is considered inferior or superior to the other, and the primary investigator (Dr. Kenneth Cohen) routinely uses both methods.

No studies have directly compared wound-healing characteristics between these two methods. We seek to compare differences in:

  1. Surgically-induced astigmatism (changes in the corneal curvature from cataract surgery incisions.
  2. Endothelial cell density loss. Endothelial cells line the inside surface of the cornea, and their overall density can be decreased by cataract surgery.
  3. Best-corrected vision after surgery
  4. Sizes of the incisions after lens injection

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Eligible patients include those who undergo uncomplicated cataract extraction surgery and IOL implantation by KLC.

Exclusion Criteria: Patients who:

  1. suffer from diabetes and have more than mild background diabetic retinopathy,
  2. have a history of intraocular surgery,
  3. have a history of ocular trauma,
  4. have known pathology of the cornea,
  5. have a history of intraocular inflammation,
  6. are unable to understand English,
  7. are decisionally impaired,
  8. are currently incarcerated, or
  9. are less than 18 years of age.

No exclusions will be made on the basis of gender, ethnicity, or race.

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Please refer to this study by its identifier: NCT01250964

United States, North Carolina
Kittner Eye Center
Chapel Hill, North Carolina, United States, 27599
Sponsors and Collaborators
University of North Carolina, Chapel Hill
Principal Investigator: Kenneth Cohen, MD UNC dept. of ophthalmology
  More Information

Responsible Party: Dr. Kenneth Cohen, Dept. of Ophthalmology, UNC Chapel Hill Identifier: NCT01250964     History of Changes
Other Study ID Numbers: 10-0435
Study First Received: November 29, 2010
Last Updated: November 30, 2010

Additional relevant MeSH terms:
Lens Diseases
Eye Diseases
Refractive Errors processed this record on May 23, 2017