A Novel Method to Assess the Cornea Biomechanical Properties With Schiotz Tonometer

Zhiwei Li

Status: Unknown

Conditions: Keratoconus

Treatments: Device: Topcon CT-80, Topcon, Japan; Device: femto-LASIK; Device: UVA/riboflavin; Device: Tomey SP-100 Pchymeter , Topolyzer Vario; Device: Schiotz tonometer; Device: Corvis-ST

Study type: Interventional

Funder types: Other

Identifiers

NCT02475343

No.018

Details and patient eligibility

About

This study aims to use Schiotz tonometer to evaluate the corneal biomechanical properties. The administration of Schiotz tonometer is according to the routine protocol which is use to measure intra-ocular pressure. The results obtained from Schiotz tonometer will be compared with results obtained from ORA and/or Corvis.

Full description

Schiotz tonometer, since it firstly be developed more than 100 years ago by Hjalmar Schiotz, has been regarded as a classical method to evaluate intraocular pressure (IOP). In present study, we aims to measure the corneal biomechanical properties with schiotz tonometer and elucidate the clinical significance of this novel measurement. The corneal biomechanical property was calculated with subtracting the value displayed under loaded weight 5.5g from that under loaded weight 7.5g. We named the corneal biomechanical properties obtained with schiotz tonometer as Mulee factor, and the formulation is Mulee factor=value under loaded weight 7.5g (Value 7.5G)-value under loaded weight 5.5g (Value 5.5G).

Enrollment: 1,000 estimated patients

Sex: All

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• People without the disease mentioned in exclusion criteria part.

Exclusion criteria

• Patients with ocular diseases including keratitis, conjunctivitis, history of chronic eye/systemic diseases except myopia and keratoconus, history of ocular surgery except LASIK, pregnant or lactating females.

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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1,000 participants in 3 patient groups

Control

Experimental group

Description:

People without keratoconus, history of ocular surgery, and other diseases mentioned in exclusion criteria. Normal people will receive treatment or measurement including: Schiotz tonometer measurement, UVA/riboflavin corneal crosslinking, Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination.

Treatment:

Device: UVA/riboflavin

Device: Tomey SP-100 Pchymeter , Topolyzer Vario

Device: femto-LASIK

Device: Corvis-ST

Device: Schiotz tonometer

Device: Topcon CT-80, Topcon, Japan

Keratoconic patients

Experimental group

Description:

Patients with keratoconus.Keratoconic patients will receive treatment or measurement including:Schiotz tonometer measurement, UVA/riboflavin corneal crosslinking,Ocular morphology measurement,and routine ophthalmic examination.

Treatment:

Device: UVA/riboflavin

Device: Tomey SP-100 Pchymeter , Topolyzer Vario

Device: Corvis-ST

Device: Schiotz tonometer

Device: Topcon CT-80, Topcon, Japan

Patients received keratoplasty

Experimental group

Description:

Patients received keratoplasty. Patients received keratoplasty will receive treatment or measurement including:Schiotz tonometer measurement,Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination..

Treatment:

Device: Tomey SP-100 Pchymeter , Topolyzer Vario

Device: femto-LASIK

Device: Corvis-ST

Device: Schiotz tonometer

Device: Topcon CT-80, Topcon, Japan