[Fluorescence of the middle ear].

Background: Discussions of the detection of fluorescein in the perilymph after intravenous (IV) administration have been contradictory. Differentiating between the fluorescence of mucosa and fluorescence signals of extravasation or perilymph fistulas seems to be rather difficult.

Patients And Methods: We performed fluorescence endoscopy of the middle ear after IV administration of fluorescein, twice after intrathecal application, in 53 patients suffering functional cochleovestibular disturbances without improvement by infusion therapy or together with a tympanoplasty or tympanotomy. Endoscopic signs were documented in 40 patients.

Results: Fluorescence of the eardrum in blue light was detected immediately (15-20 s) after IV injection of fluorescein. A maximum amount of mucosa fluorescence was found an average of 4 min later, decreasing up to 120 min (average 55 min). Fluorescence of the middle ear mucosa increased faster and lasted longer in ears with chronic otitis than in ears without signs of inflammation. Fluorescence signals of liquid in the round or oval niche were observed in 25 patients an average of 30 min after the IV administration. We documented these signals up to 240 min after administration, depending on the period between injection and start of the operation as well as the operating procedure. Probes of liquid >5 mul in the round niche could be sampled in three patients. These probes showed a significantly increased beta fraction in protein electrophoresis.

Conclusion: The choice of the right examination time point (45 min up to 2 h after IV administration) seems to be crucial for fluorescence endoscopy of the middle ear, as this method is a dynamic procedure.