Keratoconus
Conditions
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).
Interventions
DEVICESchiotz tonometer
The corneal biomechanical properties will be measured using a Schiotz tonometer with routine manipulation protocol.This measurement will be used in normal people, keratoconic patients, patients received keratoplasty.
DEVICEUVA/riboflavin
The UVA/riboflavin corneal crosslinking will be applied using a UV-X lamp (Peschke Meditrade GmbH, Switzerland) with routine manipulation protocol (3mW/cm2, 365nm, 30 minutes).This treatment will be used in keratoconic patients.
DEVICEfemto-LASIK
The keratoplasty mainly include femto-LASIK (Laser in situ keratomileusis), which will be applied using a Wavelight FS200 and Wavelight EX500 Excimer Laser (Alcon Inc. USA.).The keratoplasty will be applied in patients who would like to receive the surgery.
DEVICETomey SP-100 Pchymeter , Topolyzer Vario
Cornea thickness will be measured with a pachymeter (Tomey SP-100 Pchymeter, Japan); cornea topography will be measured with Topolyzer Vario (Allegro, Wavelight GmBH, Germany); anterior chamber depth, white to white, and ocular axis length will be measured using a IOL master (Carl Zeiss Meditec, Germany). These measurements will be used in normal people, keratoconic patients, patients received keratoplasty.
DEVICETopcon CT-80, Topcon, Japan
Vision acuity will be measured with a decimal visual chart; IOP (Intra-ocular pressure) will be measured with a tonometer (Topcon CT-80, Topcon, Japan) , fundoscopy examination will be apllied with a direct ophthalmoscopy, slit lamp examination will be applied with a slit lamp. These examinations will be used in normal people, keratoconic patients, patients received keratoplasty.
DEVICECorvis-ST
Cornea biomechanical properties will be measured with a ocular response analyzer (Reichert, USA.) and/or a Corvis-ST (Oculus, Germany).These measurements will be used in normal people, keratoconic patients, patients received keratoplasty.
Sponsors
Zhiwei Li
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Healthy volunteers
Yes
Inclusion criteria
* People without the disease mentioned in
Exclusion criteria
part.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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 |
Countries
China
Contacts
Primary ContactZhiwei Li, MD.
Outcome results
None listed