Biomaterial Database

Variability of Central Corneal Thickness Measurements-Comparing Zeiss IOL Master and Tomey Corneal Specular Microscope. 2019

James Yuheng Jiang, and Keith Ong

University of Sydney, Sydney, Australia.

OBJECTIVE The aim of this study was to compare the intraobserver repeatability and agreement of central corneal thickness (CCT) measurements by 2 commonly available instruments, Zeiss IOL Master 700 (SS-OCT-based optical biometry device) and Tomey corneal specular microscope EM-3000 (Noncontact specular microscopy). METHODS Retrospective study. METHODS This is a retrospective analysis of data from routine clinical practice in which preoperative CCT measurements of 105 patients scheduled for cataract surgery were analyzed. Two consecutive CCT measurements were measured using Zeiss IOL Master 700 and Tomey corneal specular microscope EM-3000 by the same examiner. The repeatability of CCT measurements was analyzed by mean intraobserver difference, coefficient of repeatability (CR), and intraclass correlation. The agreement between the 2 methods was analyzed by mean difference and limits of agreement (LoA) using the Bland-Altman method. RESULTS The mean absolute intraobserver difference between the 2 measurements by Zeiss and Tomey were 3.41 ± 3.98 μm and 8.62 ± 9.52 μm (P < 0.0001), respectively. For Zeiss, the CR was 10.3 μm with 95% LoA of -10.5 to 10.1 μm. For Tomey, the CR was 25.2 μm with 95% LoA of -25.2 to 25.2 μm. The mean CCT measurements ± standard deviation by Zeiss and Tomey were 544.0 ± 38.1 μm and 532.6 ± 40.0 μm, respectively (P = 0.003). The 95% LoA in CCT between the 2 methods was -15.8 to 38.7 μm. CONCLUSIONS Zeiss IOL Master 700 has superior intraobserver repeatability and consistency than Tomey EM-3000. Zeiss produced higher CCT measurements than Tomey; hence, in clinical practice, interchangeability between these 2 methods is limited.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D002387	Cataract Extraction	The removal of a cataractous CRYSTALLINE LENS from the eye.	Enzymatic Zonulolysis,Phakectomy,Cataract Extractions,Enzymatic Zonulolyses,Extraction, Cataract,Extractions, Cataract,Phakectomies,Zonulolyses, Enzymatic,Zonulolysis, Enzymatic
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D005260	Female		Females
D005500	Follow-Up Studies	Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.	Followup Studies,Follow Up Studies,Follow-Up Study,Followup Study,Studies, Follow-Up,Studies, Followup,Study, Follow-Up,Study, Followup
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D012189	Retrospective Studies	Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.	Retrospective Study,Studies, Retrospective,Study, Retrospective

Related Publications

James Yuheng Jiang, and Keith Ong

Repeatability of central corneal thickness measurements measured with the Topcon SP2000P specular microscope.

August 2005, Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie,

James Yuheng Jiang, and Keith Ong

Central and peripheral corneal thickness measured with the TOPCON specular microscope SP-2000P.

October 2000, Current eye research,

James Yuheng Jiang, and Keith Ong

[Normal value of the central corneal thickness measured by non-contact specular microscope].

December 2004, Yan ke xue bao = Eye science,

James Yuheng Jiang, and Keith Ong

Corneal thickness measurements with the Topcon SP-2000P specular microscope and an ultrasound pachymeter.

July 1999, Archives of ophthalmology (Chicago, Ill. : 1960),

James Yuheng Jiang, and Keith Ong

Comparison of central corneal thickness measurements by Pentacam, noncontact specular microscope, and ultrasound pachymetry in normal and post-LASIK eyes.

October 2009, Saudi journal of ophthalmology : official journal of the Saudi Ophthalmological Society,