Original articleComparison of Three Methods of Measuring Corneal Thickness and Anterior Chamber Depth
Section snippets
Methods
Eighty-eight eyes of 44 young volunteers were included in this prospective study. The subjects had to be healthy except for myopia/hyperopia and/or astigmatic ametropia. Exclusion criteria were other ocular diseases such as glaucoma and retinal pathology, or any history of ocular surgery, including (refractive) laser surgery. The volunteers were informed about the purpose of the study and had to give informed consent before inclusion. The study was performed in adherence to the Declaration of
Results
The mean age of the 44 subjects was 23.6 years (range, 21–32 years). The mean spherical equivalent was −2.15 D (range, −8.5 to +3.0 D). 13. There were seven contact lens wearers who removed the lenses at least 12 hours before the study. Both eyes of all subjects (88 eyes) could be measured with the three instruments. Mean total examination time was 25 minutes per subject (approximately 15 minutes for Pentacam and Orbscan, and 10 minutes for the AC-Master measurements including scan evaluation).
Discussion
Accurate measurement of CT and ACD has become important with the rapidly increasing popularity of corneal refractive surgical procedures and with the implantation of new (phakic) intraocular lenses. In this study, we have compared three different noncontact optical methods of measuring CT and ACD. Two of these instruments, the AC-Master and the Pentacam, have been made commercially available only quite recently. The Orbscan is an already established method and was made commercially available
Reporting visual acuities
The AJO encourages authors to report the visual acuity in the manuscript using the same nomenclature that was used in gathering the data provided they were recorded in one of the methods listed here. This table of equivalent visual acuities is provided to the readers as an aid to interpret visual acuity findings in familiar units.
Snellen Visual Acuities Empty Cell Empty Cell 4 Meters 6 Meters 20 Feet Decimal Fraction LogMAR 4/40 6/60 20/200 0.10 +1.0 4/32 6/48 20/160 0.125 +0.9 4/25 6/38
Wolf BUEHL, MD
Department of Ophthalmology
Medical University of Vienna
Waehringer Guertel 18-20, Vienna 1090, Austria
phone: +43-1-40400-7944
Date of birth: 24.5.1974
2000: PhD Thesis (“Fully automated analysis of PCO”)
2000–2002: Research fellow in Ophthalmology, Medical University of Vienna
Since 2002: Clinical fellow in Ophthalmology, Medical University of Vienna
Primary research interests:
- •
Cataract surgery
- •
Intraocular lenses
- •
Posterior capsule opacification (PCO)
- •
Biometry
- •
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Wolf BUEHL, MD
Department of Ophthalmology
Medical University of Vienna
Waehringer Guertel 18-20, Vienna 1090, Austria
phone: +43-1-40400-7944
Date of birth: 24.5.1974
2000: PhD Thesis (“Fully automated analysis of PCO”)
2000–2002: Research fellow in Ophthalmology, Medical University of Vienna
Since 2002: Clinical fellow in Ophthalmology, Medical University of Vienna
Primary research interests:
- •
Cataract surgery
- •
Intraocular lenses
- •
Posterior capsule opacification (PCO)
- •
Biometry
- •
Digital imaging of the anterior segment
- 1
W.D. is a consultant for Carl Zeiss Meditec (Jena, Germany).