PURPOSE: A fundus video camera and a nonconfocal scanning laser ophthalmoscope (SLO) detect direct light and indirect light, whereas a confocal SLO detects mostly direct light. Differences in confocal and nonconfocal SLO images and fundus video camera images are most likely due to their different optical systems. These differences were examined in indocyanine green (ICG) angiograms of a choroidal nevus. METHODS: A confocal SLO, a nonconfocal SLO, and a high resolution digital fundus video camera were used to obtain ICG angiograms of pigmented choroidal nevi in 4 patients for 30 minutes following dye injection. RESULTS: All the angiograms showed a hypofluorescent region in the nevus until 10-14 minutes after dye injection, except in 1 patient in whom no hypofluorescent region was seen in an early confocal-SLO angiogram. From 20 minutes to 30 minutes postinjection, the hypofluorescent regions were still visible in all fundus video camera angiograms and nonconfocal SLO angiograms but not in confocal SLO angiograms. CONCLUSIONS: Early angiograms taken with the three angiography systems showed a similar appearance of the choroidal nevus. However, late ICG angiograms with a confocal SLO showed different images from those taken with a nonconfocal SLO or a fundus video camera. It is suggested that the angiography system and the aperture size of an SLO should be selected according to the aspect of the pigmented choroidal nevus that is of interest in late-phase ICG angiography.

Adult↗

PubMedDate not supplied

Long-term follow-up of severe central serous chorioretinopathy using indocyanine green angiography.

BACKGROUND: The severe types of central serous chorioretinopathy (CSC) have a chronic nature, suggesting that a pathological process persists subclinically. Indocyanine green (ICG) angiography recently revealed intrachoroidal dye leakage and its static nature in CSC. As the intrachoroidal dye leakage was suspected to be relevant to the disease process, the long-term persistence of intrachoroidal ICG leakage was examined in four patients of the severe types of CSC. METHODS: ICG angiography was performed periodically over more than three years in three patients and two years in one patient. One patient had CSC with bullous retinal detachment, and the other three had chronic CSC or diffuse retinal pigment epitheliopathy. RESULTS: Intrachoroidal ICG leakage persisted in all the patients. However, a change in location of persistent intrachoroidal leakage or disappearance of intrachoroidal leakage regardless of no progression of retinal pigment epithelial alteration was noted in one eye of two patients. CONCLUSIONS: Pathology causing intrachoroidal ICG leakage persisted subclinically for a long period. However, location and extent of the intrachoroidal leakage could change during a long-term follow-up period.

Adult↗

PubMedDate not supplied

Perception of sound through direct oscillation of the stapes using a piezoelectric ceramic bimorph.

An ossicular vibrator of original design made from a piezoelectric ceramic bimorph was described. To test its effectiveness, the vibrator was temporarily implanted during tympanoplasty in four selected patients who had suffered extensive damage to the middle ear. By use of a special applicator, the vibrator was connected to either the stapes or the columella and was then excited by pure tone and speech signals. The subjects could hear well with the vibrator and distinguish speech signals. Thus a vibration threshold curve and a vibratory speech discrimination score were obtained. Comparing these with the results of conventional audiometry, the vibrator proved to be a highly efficient sound-conducting device. This study furthermore calls attention to some practical applications of this device, particularly to the possibility of implanting the vibrator as part of an implantable hearing aid.

Adult↗

PubMedDate not supplied

Orientation of stapedial nerve fibers in the facial nerve trunk.

By staining with toluidine blue and vital staining with methylene blue, the topographical orientation of the stapedial nerve fibers in the facial nerve trunk was visualized in adult guinea pigs. The stapedial nerve with its perineural sheath emerges from the facial nerve trunk in the posteromedial aspect of the upper part of the vertical portion. Toward the horizontal portion, the stapedial nerve fibers gradually ramify, lose their investments, and intermingle with other nerve fibers inside the facial nerve trunk. In the labyrinthine portion, the stapedial nerve fibers are distributed diffusely near the surface along the posterior, medial, and anterior margins of the facial nerve trunk. These findings lead to the conclusion that the stapedial nerve fibers of guinea pigs do not form a single funiculus throughout the intratemporal course of the facial nerve.

Animals↗

PubMedDate not supplied

Effects of facial nerve compression on the stapedial nerve.

A series of experiments on guinea pigs was conducted to determine the prognostic dependability of the stapedial reflex measurement in Bell's palsy. Comparison of the threshold of evoked electromyographic response of the stapedius muscle with that of the orbicularis oris muscle revealed that the stapedial nerve had a lower excitability than did the nerve innervating the orbicularis oris muscle. This lower excitability correlates with the histological finding that the stapedial nerve fibers have a smaller average diameter. The results indicate the resistance of the stapedial nerve to injury of the facial nerve. Functional recovery after cramping of the facial nerve tended to occur later in the stapedial nerve than in the nerve innervating the orbicularis oris muscle. The resistance of the stapedial nerve and the longer period required to recover function in this nerve were factors influencing the prognostic ambiguity of this test.

Animals↗

PubMedDate not supplied

Clinical assessment of ossicular mobility by a ceramic vibrator designed for implantable hearing aids.

Ossicular mobility was assessed by direct coupling of a piezoelectric ceramic vibrator to the ossicles during middle ear surgery. The sites excited were body of the incus, head of the stapes, and footplate of the stapes through a hydroxyapatite ceramic strut. The threshold of the vibratory hearing was determined by the patient's response as a minimum audition, and the vibration threshold was obtained by subtracting the preoperative bone conduction threshold from the vibratory hearing threshold. The results were analyzed by the state of hearing after the operation, which revealed that a patient with a good vibration threshold during the operation had a tendency to get good postoperative hearing. This may mean that postoperative hearing can be predicted to some extent during the operation by the measurement of ossicular mobility.

Adolescent↗

PubMedDate not supplied

Incidence of Bell's palsy.

The annual incidence of Bell's palsy in three consecutive years--1984, 1985, and 1986--was investigated in Ehime Prefecture in Japan, which has a population of 1,530,000. The number of new patients with Bell's palsy was solicited from 1,377 medical institutions and their referral hospitals. The clinical records of the 15 main hospitals were examined personally by the author to confirm the exact numbers. Special care was taken to ensure minimal error in the present epidemiologic investigation. The annual incidence of Bell's palsy per 100,000 population was found to be 30, and no annual variation was noted. The ratio of male to female patients was 48:52 in all cases. There was no geographic difference in incidence.

Facial Paralysis↗