Optic Nerve Head Structural Response to IOP Elevation in Patients With Keratoconus

Summary

The mechanism by which vision loss in glaucoma occurs is still unknown, but it is clear that increased Intraocular Pressure (IOP) is a major risk factor. It is also thought that the lamina cribrosa (LC) is a site of primary damage during the pathogenesis of the disease. The changes caused by intraocular pressure (IOP) modulation at the level of the optic nerve head and LC will be evaluated in the present study. Subjects with keratoconus exhibit abnormal collagen properties that can impair their LC behavior. By evaluating their lamina biomechanical response we can advance our understanding on the role of the lamina in glaucoma pathogenesis. A better understanding of the process will ultimately lead to improved detection and management of glaucoma.

It is hypothesized that subjects with keratoconus have an abnormal biomechanical response of the lamina cribrosa in response to IOP modulation.

Conditions

• Keratoconus
• Glaucoma

Interventions

DEVICE

Ophthalmodynamometer

The ODM (Baillart ophthlmodynamometer) is a disc attached to a piston that induces a controlled force on a fixed area. The device will be used to apply a pressure within the range of 10 mmHg - 50 mmHg 4 times to each eye. Each increase of pressure will last approximately 30 seconds. The device is FDA approved and will be used as routinely used in clinical practice

DEVICE

Goldmann applanation tonometer

The Goldmann applanation tonometer (Haag-Streit, Basel, Switzerland) measures the IOP after the eye is numbed with a drop of anesthetic (proparacaine), which is approved by the FDA. Proparacaine is part of routine patient care using a tonometer regardless of participation in this study. The instrument's tip lightly touches the surface of the cornea and the IOP is measured. The device is FDA approved is routinely used in clinical practice.

DEVICE

Pentacam

This device maps the cornea and provides pachymetry, topography and corneal aberration maps. The device is FDA approved and routinely used in clinical practice.

DEVICE

ORA

ORA is an air puff tonometer that applies controlled force to flattens the cornea and provides the corneal hysteresis and corneal resistance factor. The device is FDA approved and routinely used in clinical practice.

DEVICE

Optical Coherence Tomography (OCT)

OCT is a non-contact,real-time, high resolution, and reproducible imaging modality that provides in-vivo optical cross-sectional scanning of the retina, the ONH and of the anterior segment structures including the cornea. Clinical staff will perform subject testing, not research coordinators. Information about these non-FDA approved OCTs and the multi-modal adaptive optics system can be found in appendices A, B, C, and D. With all devices, the participant sits in a slit lamp like frame. A low power laser light is projected toward the back of their eyes while the subject fixates on a target. None of the systems produce harmful radioactive radiation.

Sponsors & Collaborators

• National Eye Institute (NEI)

  collaborator NIH

• NYU Langone Health

  lead OTHER

Principal Investigators

• Chaim Wollstein · NYU Langone Health

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2018-11-15

Primary Completion

2023-02-10

Completion

2024-01-19

FDA Device

Yes

Countries

• United States

Study Locations