Comparison of Five Camera Systems for Capturing and Grading Trachoma Images

Area of Science:

• Ophthalmology
• Public Health
• Medical Imaging

Background:

• Training trachoma graders using live participants is challenging and costly.
• Photography may offer an alternative to field grading for trachoma assessment.
• Minimum camera specifications for high-quality trachoma images are undefined.

Purpose of the Study:

• To compare image quality from four smartphones against a Nikon SLR camera.
• To assess the suitability of smartphone-captured images for grading trachomatous inflammation - follicular (TF).

Main Methods:

• Four smartphones (Samsung Galaxy S8, Techno Camon 17 pro, Infinix Note 10 pro, Huawei p30 pro) and a Nikon SLR were used.
• Images were captured from 129 children in Tanzania with a 32.8% TF prevalence.
• Image gradability and agreement with field grading were analyzed.

Main Results:

• The SLR camera yielded the fewest ungradable images (3.1%), followed by Samsung S8 (14%) and Huawei p30 pro (23.4%).
• Infinix Note 10 pro (65.9%) and Techno Camon 17 pro (71.2%) had high rates of ungradable images.
• Agreement between SLR and field grade was substantial (kappa=0.73); agreement with gradable smartphone images was also measured.

Conclusions:

• Smartphone specifications did not predict image quality for trachoma grading.
• Proprietary software likely impacts image gradeability.
• Smartphones may be viable for trachoma image capture if image quality is sufficient.