Corneal Sensitivity in Patients With Sleep Apnea Syndrome

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT02265133
Recruitment Status : Recruiting
First Posted : October 15, 2014
Last Update Posted : August 15, 2018
Information provided by (Responsible Party):
University of Texas Southwestern Medical Center

Brief Summary:

This study is a prospective, single center clinical trial to assess corneal sensitivity and nerve fiber morphology in patients with sleep apnea compared to normal controls. Healthy volunteers with no history of ocular or uncontrollable systemic disease will be encouraged to participate in the study. After execution and review of the consenting procedures, a detailed history will be taken and a slit lamp examination performed, verifying ocular health. This consists of an examination of both eyes including assessments of ocular lids, lashes, cornea and conjunctival evaluation. Corneal touch thresholds will be tested with a Cochet-Bonnet aesthesiometer, a standard non-invasive measure of corneal sensitivity. Corneal nerves will be imaged using a modified HRT in vivo confocal microscope. The in vivo confocal microscope allows for high resolution imaging of the nerve plexus under the corneal epithelium. This corneal nerve plexus is responsible for corneal sensitively and changes or loss have been established as an early, sensitive indicator of corneal neuropathy. The investigators anticipate that this study will require approximately 30 patients for each group and will last approximately 12 months for recruitment and completion of subject visit phases. There is only one clinical visit designed for this project, unscheduled visits may be scheduled in case of an adverse event.

Patient recruitment will be complete at the one-year time point. At the 14 month time point, all data points will have been collected and assessment of the outcome measure (corneal sensitivity in sleep apnea patients versus control patients) will be complete.

Condition or disease
Sleep Apnea

Detailed Description:

Screening Assessment: Following the execution of informed consent, subjects will be carefully screened for ocular signs and symptoms, consistent with the protocol inclusion and exclusion criteria. This includes review of ocular and medical history including use of concomitant & ocular medications and surgeries performed in the past. Researchers will also collect age, ethnicity, demographics, ophthalmic notes and eye exam history. Upon completion of the screening exam, subjects will be deemed eligible based on study criteria the testing procedures will be performed by the investigators.

Testing procedures: The visit will include:

Slit Lamp Microscopy:

An ocular examination of the external (lids, lashes) along with internal (cornea, lens, retina) structures of the eye can be performed with the aid of a slit lamp. This instruments uses lenses and an external light source that can be refracted at different angles and intensities to assess ocular structures for diagnostic purposes.

Corneal sensitivity measurement:

  1. Corneal touch sensitivity will be determined using a Cochet-Bonnet aesthesiometer mounted on a standard slit lamp biomicroscope. The Cochet-Bonnet aesthesiometer is routinely used for clinical research purposes to investigate corneal touch thresholds.
  2. For sensitivity measurements, a 0.12 mm diameter nylon thread will be slowly brought forward to briefly touch the cornea perpendicularly and then quickly withdrawn.
  3. On each occasion, the patient will be asked to respond whenever a stimulus is felt.
  4. Thread length is used to quantitatively assess sensitivity. The longest thread length is used first (6 cm), as this provides the lowest stimulus intensity.
  5. If the subject is unable to detect the touch stimulus, the thread will be systematically shortened in length by 0.5 cm steps until the stimulus is felt.
  6. The criterion for the sensitivity threshold will be the filament length which gives a 50% positive response from four stimulus applications.

In Vivo Confocal Microscope

  1. Corneal nerves will be imaged using a modified in vivo confocal microscope which is routinely used in our clinics (HRT Rostock corneal module, Heidelberg Engineering).
  2. The HRT In Vivo Confocal microscope was modified by adding a motor to automate the focus. This does not alter the integrity, the application, the intent or the light source of the instrument.
  3. Corneas will be anesthetized with a topical anesthetic, proparacaine, prior to scanning.
  4. The confocal microscope will briefly touch the patient's eye and the images saved for further analysis.

Study Type : Observational
Estimated Enrollment : 70 participants
Observational Model: Case-Control
Time Perspective: Prospective
Official Title: Corneal Sensitivity and Nerve Fiber Morphology in Patients With Sleep Apnea Syndrome
Study Start Date : December 2011
Estimated Primary Completion Date : December 31, 2018
Estimated Study Completion Date : July 31, 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Allergy Sleep Apnea

Primary Outcome Measures :
  1. Corneal Sensitivity [ Time Frame: 1-Day ]
    To investigate whether diminished corneal sensitivity contributes to corneal problems commonly reported in patients with sleep apnea. Specifically, this study will correlate changes in corneal touch thresholds with corneal nerve fiber morphology using in vivo confocal microscopy.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   18 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Sleep Apnea and normal controls

Inclusion Criteria:

  1. Healthy, non-smoking volunteers.
  2. Patients with a diagnosis of sleep apnea.
  3. Non-contact lens wearers of any gender and race, ages 18 and up.
  4. Minority representation will be proactively encouraged.
  5. Patients that are willing to review, understand, and sign the written Informed Consent.
  6. Written authorization for use or release of health and research study information.
  7. Patients that are willing and able to cooperate with the Investigator and follow all instructions.

Exclusion Criteria:

  1. Use of ocular drops including over the counter (OTC) dry eye drops.
  2. Previous history of corneal surgery.
  3. Previous history of ocular trauma.
  4. History of Diabetes Mellitus.
  5. Current active or previous history of Herpes virus keratitis.
  6. Current or former Contact lens wear.
  7. Chronic history of dry eye disease.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02265133

Contact: Bryan Gallerson 214-645-2013
Contact: Bonnie Miller, PhD 214-648-3826

United States, Texas
Parkland Hospital Recruiting
Dallas, Texas, United States, 75235
Contact: Bryan Gallerson    214-645-2013   
Aston Ambulatory Care Center Recruiting
Dallas, Texas, United States, 75390
Contact: Bryan Gallerson    214-645-2013   
Contact: Bonnie Miller, PhD    214-648-3826   
Sponsors and Collaborators
University of Texas Southwestern Medical Center
Principal Investigator: Danielle Robertson, O.D, PhD UTSW Medical Center at Dallas

Responsible Party: University of Texas Southwestern Medical Center Identifier: NCT02265133     History of Changes
Other Study ID Numbers: 102011-033
First Posted: October 15, 2014    Key Record Dates
Last Update Posted: August 15, 2018
Last Verified: August 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases