slide1
Download
Skip this Video
Download Presentation
Oliver Findl 1,2 , Nino Hirnschall 1,2 , Alja Crnej 2 1 VIROS Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria

Loading in 2 Seconds...

play fullscreen
1 / 11

Oliver Findl 1,2, Nino Hirnschall 1,2, Alja Crnej 2 1 VIROS Vienna Institute for Research in Ocular Surgery, Hanusch - PowerPoint PPT Presentation


  • 153 Views
  • Uploaded on

Effect of Fluorescein dye staining of the tear film on Scheimpflug measurements of central corneal thickness. Oliver Findl 1,2 , Nino Hirnschall 1,2 , Alja Crnej 2 1 VIROS Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Oliver Findl 1,2, Nino Hirnschall 1,2, Alja Crnej 2 1 VIROS Vienna Institute for Research in Ocular Surgery, Hanusch ' - nikki


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Effect of Fluorescein dye staining of the tear film on Scheimpflug measurements of central corneal thickness

Oliver Findl 1,2, Nino Hirnschall 1,2, Alja Crnej 2

1 VIROS Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria

2 Moorfields Eye Hospital, London, UK

Financial interest: none

OF is scientific advisor to Alcon, AMO, Croma & Carl Zeiss Meditec AG

background
Background
  • Fluorescein dye is commonly used in routine ophthalmic examination
    • staining epithelial defects of the cornea
    • break up time of the tear film
    • Goldmann applanation tonometry
  • Correct CCT measurement needed for:
    • corneal refractive surgery
    • diagnosis of corneal diseases (keratoconus)
    • to correct for systematic errors of IOP measurements using Goldmann applanation.
cct measurement devices
CCT measurement devices
  • Pentacam: rotating Scheimpflug photographic
    • measures the thickness from the image, which is created from the back-scattered light from the corneal tissue

=> Influenced by fluorescein eye drops?

  • ACMaster: partial coherence interferometry (PCI)
    • gold standard for CCT measurement
    • measures distances between surface interfaces with a different refractive index
methods
Methods
  • Prospective randomised controlled study
  • 30 eyes of 15 patients (8 female, 7 male)
methods1
Methods

3 x rotating Scheimpflug imaging + 3 x PCI measurement

Instilling 0.25% fluorescein +

0.5% proxymetacaine hydrochloride

Rotating Scheimpflug imaging + PCI measurement

Irrigation with 2ml BSS

Rotating Scheimpflug imaging + PCI

after 5min, 10min, 20min, 40min, 60min, (120min)

Rotating Scheimpflug imaging + PCI

slide6

With Fluorescein

Without Fluorescein

results
Results

Rotating Scheimpflug: 46.6µm difference

PCI: 1.6µm difference

results1
Results

CCT difference (PCI) in µm

CCT difference (Scheimpflug) in µm

results2
Results

Number of patients (%) with a fluorescein layer +5µm compared to baseline

Subjects with Fluorescein layer (%)

time after applying Fluorescein (min)

Fluorescein layer -> more than 5µm difference to the baseline measurement

results3
Results

Schirmer 2 results (sec)

time after applying Fluorescein (min)

conclusion
Conclusion
  • Scheimpflug imaging
    • Fluorescein dye causes intense back-scatter of light resulting in a measurement error
    • Irrigating the eye reduces this effect only insignificantly
  • PCI: is not influenced by altered or higher reflectivity
  • => Fluorescein eye drops MUST NOT be used prior to Scheimpflug imaging measurements
ad