Ideal Illumination for Smartphone-based Trabeculectomy Bleb Photography

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Surgery

Background:

• Smartphones offer novel applications in ophthalmology, including fundus photography and telemedicine.
• Anterior segment photography for trabeculectomy bleb morphology assessment using smartphones remains underexplored.

Purpose of the Study:

• To characterize ideal illumination for anterior segment smartphone photography in patients post-trabeculectomy.
• To evaluate the reliability of smartphone anterior segment photography for bleb morphology assessment.

Main Methods:

• Thirty patients post-trabeculectomy were enrolled.
• Images were captured using native and FiLMiC Pro apps on iPhone X with yellow and white pen-torches.
• ImageJ software and R software were used for area measurement, consistency analysis (ANOVA), and repeatability (Bland-Altman plots).
• Signal-to-noise ratio (SNR) and inter-observer agreement (kappa coefficient) were calculated.

Main Results:

• No significant difference in measured bleb area between the two camera apps, indicating consistency.
• Bland-Altman analysis confirmed good repeatability and reproducibility of measurements.
• Lower SNR was observed with close illumination compared to intermediate and distant illumination.
• Substantial agreement between observers was found for images captured with distant white light (kappa=0.7) and intermediate yellow light (kappa=0.65).

Conclusions:

• Smartphone photography is a reliable tool for assessing trabeculectomy bleb morphology.
• Optimal intermediate or distant illumination is crucial for high SNR, minimizing digital noise and overexposure.
• Proper illumination enhances the delineation of morphological features, improving diagnostic accuracy.