Rosai-dorfman disease diagnosed because of bilateral choroidal masses.

PURPOSE: To describe a case of bilateral choroidal masses leading to the diagnosis of Rosai-Dorfman disease. METHOD: Case report. Color photographs, fluorescein angiography, autofluorescence, indocyanine green angiography, and high-definition optical coherence tomography imaging of both eyes and computed tomography and biopsy of pelvis mass were performed. A 47-year-lady presented with unknown choroidal masses in both eyes. She had no visual complaints. Her medical history was noncontributory. RESULTS: Workup included a computed tomography of the chest and abdomen that demonstrated soft tissue masses in the renal pelvis bilaterally. A core needle biopsy from the renal mass demonstrated numerous histiocytoid that were positive for CD163 and S100 protein. CONCLUSION: Based on this spectrum of findings, the diagnosis of Rosai-Dorfman disease was made. To date, the patient has been followed-up for 3 years without medical intervention and without visual deterioration. Careful follow-up is a reasonable management if patients are asymptomatic.

Multifocal choroiditis secondary to the reactivation of epstein-barr virus.

PURPOSE: To describe a case of multifocal choroiditis associated with Epstein-Barr virus reactivation in a patient who had previously had documented infectious mononucleosis. METHODS: Color photos, fluorescein angiography, autofluorescence, indocyanine green angiography, and high-definition optical coherence tomography imaging was performed. A 39-year-old woman presented with a central scotoma in her left eye. At 19 years of age, she developed a peripapillary choroidal neovascular complex in her right eye, which was treated by laser photocoagulation. Two weeks before her visual complaint, she suffered from a frontal headache, occipital lymphadenopathy, and splenomegaly. RESULTS: Laboratory studies revealed markedly elevated immunoglobulin G titers to Epstein-Barr virus and she recalled a history of infectious mononucleosis at 20 years of age. CONCLUSION: While primary infection may manifest as infectious mononucleosis, like other viruses in the herpes virus family, there may be reactivation of the virus later in life.

Adaptation of spatiotemporal mechanisms by increment and decrement stimuli.

Sawtooth modulation has been used in the past to examine visual sensitivity to luminance increments and decrements. The threshold elevation caused by adaptation depends on the spatial profile of the stimulus field and the polarities of the adaptation and test stimuli. We hypothesized that the adaptation effects reflect a change in the sensitivity of the spatiotemporal channels that detect the stimuli. We used a 2-deg disk centered in a larger surround field. Five levels of contrast between the test field and surround were investigated: equiluminant, three intermediate levels, and dark. At each contrast, observers adapted for 5 s to 2-Hz sawtooth modulation (rapid-on or rapid-off). Immediately after adaptation, thresholds were measured for detection of a single cycle of either a rapid-on or a rapid-off waveform. Varying the contrast of the surround affected observers' sensitivity to the polarity of the sawtooth stimulus to the extent that the pattern of sensitivity with the equiluminant surround was the opposite of that with the dark surround. To examine temporal factors, we measured thresholds for slow (500-ms ramps) and fast (8.3-ms pulses) test stimuli. The adaptation effect was preserved with the ramp stimuli but not with the pulse stimuli. Blurring the edge between the test and surround fields in the equiluminant surround condition raised thresholds for all sawtooth test stimuli, suggesting that spatiotemporal channels sensitive to high spatial frequencies and low temporal frequencies facilitate detection in that condition. These findings suggest that adaptation to sawtooth modulation can differentially effect the sensitivity of ON and OFF pathways, but the relative desensitization of each pathway depends on an interaction with the adaptation state of spatiotemporal channels that are involved in detection.