Repeatability of pupil diameter measurements using three different topography devices.

Area of Science:

• Ophthalmology
• Optometry
• Medical Device Technology

Background:

• Accurate preoperative pupil diameter measurement is crucial for successful corneal refractive surgery.
• Variability in measurements between devices can impact surgical outcomes.

Purpose of the Study:

• To assess the intra-device and inter-device repeatability of pupil diameter measurements.
• To compare three specific devices: Sirius anterior segment analyzer, Pentacam HR, and IOLMaster 500.
• To determine if these devices are interchangeable for pre-refractive surgery assessments.

Main Methods:

• A study involving 204 eyes from 102 patients undergoing corneal refractive surgery.
• Three consecutive measurements were taken with each of the three devices under standardized conditions.
• Intraclass Correlation Coefficient (ICC) and Bland-Altman plots were used to analyze intra- and inter-device repeatability.

Main Results:

• Sirius (ICC=0.64) and IOLMaster 500 (ICC=0.61) showed comparable intra-device repeatability, superior to Pentacam HR (ICC=0.09).
• Sirius exhibited the highest measurement accuracy.
• Inter-device repeatability was low, indicated by wide limits of agreement between device pairs.

Conclusions:

• The intra-device repeatability of Sirius and IOLMaster was better than Pentacam, but not optimal.
• Significant differences in measurement accuracy and repeatability exist between the devices.
• The Sirius, Pentacam HR, and IOLMaster 500 cannot be used interchangeably for pre-corneal refractive surgery pupil measurements.