Eyelid and conjunctival paracoccidioidomycosis simulating carcinoma.

Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in immunocompetent individuals in Brazil. Ocular infection by PCM is rare; however, when infection does occur, the most common ocular sites involved are eyelid and conjunctiva. A 68-year-old white male presented with a 2-month history of a painless, ulcerated, infiltrative and diffuse whitish lesion located on the right inferior eyelid. A clinical diagnosis of malignant tumor, possibly squamous cell carcinoma, was made. The histopathologic examination showed a hyperplastic epithelium with inflammatory infiltrate of lymphocytes, plasma cells, neutrophils and histiocytes. Large numbers of giant cells were also present. Periodic acid Schiff and Grocott (silver methenamine) stains showed several large round structures with peripheral lateral small budding cells that resembled a "ship's wheel". No multinucleated fungi were seen. The fungi varied in size and small forms were round and single fungal structures. A diagnosis of paracoccidioidomycosis was made PCM eyelid infection is rare and can simulate carcinoma both clinically and histopathologically.

Upper and lower eyelid saccades describe a harmonic oscillator function.

PURPOSE: To determine whether experimentally measured upper and lower eyelid saccades can be fitted to a mathematical function. METHODS: A charge-coupled device video camera connected to a personal computer was used to record upper and lower eyelid saccades accompanying 20 degrees and 40 degrees of vertical eye rotation in 19 normal adult subjects. Movement analysis was performed with software that calculated the center of a blue spot in each frame. The damped harmonic oscillator model was used to fit all saccadic functions obtained. RESULTS: All downward and upward saccades of both upper and lower eyelids were fitted with the underdamped solution of the model with correlation coefficients ranging from 0.980 to 0.999 (mean = 0.995). It was possible to measure maximum velocity at any time, amplitude, and duration of the saccade movements. For the upper eyelid, downward saccades were faster than upward saccades, a difference that was not observed for the lower eyelid. For both the upper and lower eyelids, the velocity of upward and downward movements reached a peak at approximately 0.05/0.06 second and then decreased. For both the upper and lower eyelid saccades, there was good linear correlation between amplitude and velocity. Overshoots were detected in the downward saccades of both lids. CONCLUSIONS: Normal upper and lower saccades are described by functions that are extremely well fitted by the underdamped solution of the harmonic oscillator model. Overshooting is a typical feature of normal downward saccades and can be explained by the elastic properties of the tissues.