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

Not Applicable

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

• Registration Number: NCT02475343
• Lead Sponsor: Zhiwei Li

Brief Summary

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.

Detailed 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).

Study Timeline

• Study Start: 2015-02
• Study First Submitted: 2015-05-28
• Study First Submitted QC: 2015-06-17
• Study First Posted: 2015-06-18
• Status Verified: 2015-11
• Last Update Submitted: 2015-11-16
• Last Update Posted: 2015-11-18
• Primary Completion: 2016-05
• Study Completion: 2016-06

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 1000

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Keratoconic patients	Schiotz tonometer	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.
Keratoconic patients	UVA/riboflavin	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.
Control	Schiotz tonometer	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.
Keratoconic patients	Tomey SP-100 Pchymeter , Topolyzer Vario	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.
Patients received keratoplasty	Schiotz tonometer	Patients received keratoplasty. Patients received keratoplasty will receive treatment or measurement including:Schiotz tonometer measurement,Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination..
Control	UVA/riboflavin	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.
Control	femto-LASIK	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.
Control	Corvis-ST	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.
Control	Tomey SP-100 Pchymeter , Topolyzer Vario	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.
Patients received keratoplasty	Corvis-ST	Patients received keratoplasty. Patients received keratoplasty will receive treatment or measurement including:Schiotz tonometer measurement,Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination..
Control	Topcon CT-80, Topcon, Japan	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.
Keratoconic patients	Topcon CT-80, Topcon, Japan	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.
Patients received keratoplasty	femto-LASIK	Patients received keratoplasty. Patients received keratoplasty will receive treatment or measurement including:Schiotz tonometer measurement,Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination..
Patients received keratoplasty	Tomey SP-100 Pchymeter , Topolyzer Vario	Patients received keratoplasty. Patients received keratoplasty will receive treatment or measurement including:Schiotz tonometer measurement,Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination..
Patients received keratoplasty	Topcon CT-80, Topcon, Japan	Patients received keratoplasty. Patients received keratoplasty will receive treatment or measurement including:Schiotz tonometer measurement,Keratoplasty, Ocular morphology measurement,and routine ophthalmic examination..
Keratoconic patients	Corvis-ST	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.

Primary Outcome Measures

Name	Time	Method
The Mulee factor obtained with Schiotz tonometer as a measure of cornea biomechanical property	up to 1 year	Mulee factor= Value displayed with Schiotz tonometer under 7.5g load-Value displayed with Schiotz tonometer under 5.5g load

Trial Locations

Locations (1)

Shandong Provincial Hospital; 🇨🇳 Jinan, Shandong, China