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Published on: March 24, 2020
Intra-observer and inter-observer variation of Hertel exophthalmometry
Andrew K C Lam1, Chun-fai Lam, Wai-kit Leung
1School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Andrew.KC.Lam@polyu.edu.hk
Summary
Hertel exophthalmometry shows good intra-observer agreement for measuring eye protrusion. Inter-observer agreement is clinically acceptable, though differences were statistically significant.
Area of Science:
- Ophthalmology
- Medical instrumentation
- Clinical measurement
Background:
- Hertel exophthalmometry is a common clinical tool.
- Assessing measurement variability is crucial for diagnostic accuracy.
Purpose of the Study:
- To evaluate the intra-observer and inter-observer variability of Hertel exophthalmometry.
- To determine the reliability of measurements in a Chinese adult population.
Main Methods:
- Bilateral exophthalmometry was performed on 70 normal Chinese adults.
- Two masked examiners used the same Hertel exophthalmometer.
- The Bland-Altman method analyzed intra-observer and inter-observer agreement.
Main Results:
- Intra-observer agreement for interorbital distance (IOD) was +/-3.31 mm.
- Inter-observer agreement for IOD was +/-6.39 mm.
- Exophthalmometry showed good intra-observer agreement (+/-1.19 mm right eye, +/-1.09 mm left eye) and clinically acceptable inter-observer agreement (+/-1.74 mm right eye, +/-1.57 mm left eye).
Conclusions:
- Hertel exophthalmometry demonstrates good intra-observer reliability.
- Inter-observer agreement is clinically acceptable, indicating consistency between different examiners.
