Pilot study: optical coherence tomography as a non-invasive diagnostic perspective for real time visualisation of onychomycosis

Abstract

The objective of this study was to compare optical coherence tomography (OCT) with conventional techniques such as KOH-preparation, culture and histology in the identification of the fungal elements in the nail. A total of 18 patients were examined; 10 with clinically evident onychomycosis in toe nails, two with psoriatic nail lesions, one with nail affection caused by lichen planus and five healthy controls. Serial in vivo OCT analyses of onychomycosis was performed prior to KOH-preparation, culture and punch biopsy of the nail plate for consecutive histology. Fungal elements were detected non-invasively in vivo using OCT in all 10 patients with histologically proven onychomycosis. Fungal elements were detectable as highly scattering elongated structures inside the nail plate, in the middle of the areas of homogeneous decrease in signal intensity. KOH-preparations and culture did reveal a positive result in 5/6 out of 10 patients. In patients with psoriasis, lichen planus as well as in the healthy controls, no fungal infection could be detected by either method used. OCT is a reliable, easy to use, non-invasive and non-destructive method to visualise fungal elements in vivo in onychomycosis, even in cases of false negative KOH-preparation and culture. Furthermore, OCT offers the opportunity to screen several areas of the same nail plate and to detect fungal elements during local or systemic therapy.

Potential Use of Optical Coherence Tomography and High-Frequency Ultrasound for the Assessment of Nail Disease in Psoriasis and Psoriatic Arthritis

“…Two small OCT studies in HCs described the appearance of the nail using OCT; these mentioned leuconychia with a similar pattern to that which we have noted [22,29]. One other study assessed patients with a variety of nail disorders [30]. This included two patients with psoriatic nail disease, with the first description of the appearance of nail pitting.…”

“…Recent studies have shown some potential for the use of OCT in the diagnostic assessment of fungal nail disease, with good sensitivity but lower specificity than other methods [30,31]. In a separate study, a change in nail thickness has been demonstrated using OCT after exposure to water [29].…”

Vascular Features of Nail Psoriasis Using Dynamic Optical Coherence Tomography

“…These findings were consistent with our results of healthy control patients, with nail thickness falling within this range. Abuzahra et al [17] distinguished nail psoriasis from onychomycosis. Unlike nail psoriasis, which consists of homogeneous scattering within the nail plate, onychomycosis contains a high scattering area surrounded by a low scattering area, indicating the presence of fungus.…”

Optical coherence tomography: its role in daily dermatological practice

“…In-vivo diagnosis of alopecia; follow-up of same hairs; no epilation/shaving needed; results comparable to histology [ 16 ] Nail diagnosis Fungal elements may be visualized in the usually homogeneous, low-signal nail plate [ 17 ] ; currently no differentiation of pathogens; differentiation from inflammatory causes of nail changes such as lichen ruber, psoriasis, atopic dermatitis…”