Effect of Colored Ear Specula on Halation Reduction and Otoscopic Visibility Under a 4K-3D Exoscope

Objective: To determine whether ear speculum inner-surface color affects halation-related image behavior and perceived visibility during 4K-3D exoscopic otoscopy. Study design: Experimental imaging and observer preference study. Setting: Laboratory-based otoscopic imaging and observer evaluation using a spatial reality display. Participants: Twelve otolaryngology clinicians completed the subjective assessments. Intervention(s): Seven ear speculum inner-surface colors (black, silver, yellow, white, red, green, and blue) were evaluated during continuous zoom-in tympanic membrane imaging with automatic exposure and auto-white balance enabled. Main outcome measure(s): Frame-wise luminance spread, high-luminance proportion, frame-to-frame color difference in CIELAB space (ΔE76), structural similarity index, and subjective best-worst/Bradley-Terry-Luce preference scores. Results: Color significantly affected luminance spread (η² = 0.756), high-luminance proportion (η² = 0.345), structural similarity (η² = 0.205), and frame-to-frame ΔE76 (η² = 0.0059; all p ≤ 0.05). White and silver showed narrower luminance spread than black and lower high-luminance burden, whereas white had the highest subjective preference and red the lowest. Conclusions: White provided the most favorable overall balance between halation suppression and perceived visibility, with silver as a reasonable alternative. Inner-surface color is a low-cost design variable that can materially influence exoscopic otoscopy.