Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Organizational Issues.
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
The goal of the study is to investigate relationship between the corneal response to a temporary increase in intraocular pressure and corneal mechanical properties.
The preliminary theoretical study in which the corneal geometry at different intraocular pressure (IOP) levels is investigated using a theoretical biomechanical cornea model found changes in both conventional refractive error (sphere and cylinder) and irregular astigmatism i.e. higher order aberrations (e.g. spherical aberration, trefoil and quadrafoil). This is due to the mechanical characteristics of the cornea determined largely by interaction between collagen fibrils organization and extrafibrillar matrix material properties. Corneal geometry and the material properties are the two main factors that contribute to the changes in corneal aberrations with IOP elevation. These aberration changes due to the variation of IOP and the material properties of the cornea can be measured routinely with corneal topography systems (UR) and Brillouin ocular scanner (MGH), respectively and can guide the investigators to study their impact on optical and biomechanical behaviors of the cornea.
Not provided
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Experimental | Experimental | Subjects will undergo 4-5 visits total over the course of 6 months. There will be 3-4 visits that will be done at the Flaum Eye Institute. During these sessions the subject will be measured with a stationary topographer (GALILEI G4), with a rotatable topography measurement (Oculus Topographer) and a Tonometer. The subject's heart rate and blood pressure will also be measured (using a commercially available blood pressure and heart rate meter). The GALILEI measurement will only be done once. The rest of the measurements will be done up to 4 times. Once at the start of the study session then, after the subject has been inverted using a commercially available inversion table to first 135 degrees, then 150 degrees and finally to 165 degrees. The blood pressure and heart rate will be monitored to ensure subject safety. There will also be one visit at the Massachusetts General Hospital. The visit will be 2 hours and will involve a Brillouin Microscopy measurement. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Inversion | Other | Inversions will be done while the subject is on the inversion table. The subject will be inverted to 135, 150 and 165 degrees. There inversion will not last longer than 3 minutes at a time. The inversion will be terminated if the subject's blood pressure drops below 50 mmHg diastolic or if the subject's blood pressure increases more than 50 mmHg systolic. |
| Measure | Description | Time Frame |
|---|---|---|
| Corneal Surface Topography Measurement | Corneal Surface Topography measurement will be collected at each of the 3-4 study visits at the Flaum Eye Institute. The numerical data generated will be analyzed and compared within each subject as well as across subjects. | 6 months |
Not provided
Not provided
Inclusion Criteria
A person is eligible for inclusion in the study if he/she:
Exclusion Criteria
A person will be excluded from the study if he/she:
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Geunyoung Yoon, PhD | University of Rochester | Principal Investigator |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| ID | Term |
|---|---|
| D009216 | Myopia |
| ID | Term |
|---|---|
| D012030 | Refractive Errors |
| D005128 | Eye Diseases |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
|