Because of its specialized optical design, the VOE head is poorly suited to macro-videography of the pinna and concha with hearing aids in situ. The VOM macro-lens accessory is an optional feature but particularly helpful in a hearing instrument - based practice. It affords the opportunity for a broad field of view at ambient light levels. It is useful for capturing images of the entire pinna and concha, for documenting needed changes in hearing instrument morphology to the laboratory and for demonstrating hearing aid placement, adjustment and cosmetic impact to the patient. If interchangeable VO heads are not available, a second camera and lens can be dedicated to VOM applications as well as patient "mug shots" for clinical records.
The figure (A-C) below shows a contact ulceration of the medial antitragus caused by pressure from the sharp edge of a canal aid battery compartment. The edge was ground away relieving the irritation but also (FIG B) creating a hiatus into which the aid subsequently extruded. This, in turn caused slit leak with acoustic feedback. Using a VOM image, an outline of an antitragal lip (ATL) was drawn (Fig. B) and forwarded to the laboratory. The resulting ATL (Fig. C) distributed pressure evenly across the entire medial antitragus, eliminated the contact abrasion and prevented both extrusion and feedback.
The right and left pinnae / conchae of the patient shown in Fig A-B below demonstrate clearly disparate anatomical configurations. The left ear was flattened in a forceps-delivery birth. In a binaural canal aid fitting, the right aid was cosmetically acceptable, the left aid protruded significantly because of the iatrogenically shallow inferior portion of the concha. A VOM image (Fig. C), highlighting the area of cosmetic unacceptability, was forwarded to the laboratory together with the hearing aid investment. The outcome is shown in D.
Roy F. Sullivan, Ph.D.