Alteration of the optic radiations using diffusion-tensor MRI in patients with retinitis pigmentosa.

PURPOSE: To evaluate alteration of the optic radiation (OR) in patients with retinitis pigmentosa (RP) using fractional anisotropy (FA) measured by diffusion tensor MRI. METHODS: We performed MRI and evaluated alteration of the ORs in 17 patients with RP and 27 healthy controls. Regions of interest were placed over the bilateral anterior and posterior areas of the ORs, and we measured the FA value of each region. Visual field (VF) tests were examined in all subjects, and we corrected the residual VF area according to the projection area to the striate cortex. Differences between the FA values of patients and healthy controls were tested. We performed regression analyses between the sum of the corrected VF areas and FA values in the anterior or posterior contralateral ORs in patients with RP. Moreover, we performed regression analyses between the average of FA values of ORs and the average of both eyes of visual acuity in patients with RP. RESULTS: FA values of the bilateral anterior and posterior ORs were lower in patients with RP (anterior right, p=0.012; posterior right, p=0.0004; anterior left, p=0.0008; and posterior left, p=0.0004) compared with those of healthy controls. In patients with RP, significant correlations were observed between average FA values of anterior ORs and average visual acuity (correlation coefficient (r)=-0.54; p=0.025). CONCLUSIONS: In patients with RP, alterations may occur not only in the retina but also in the brain.

Glucose hypometabolism in medial frontal cortex of patients with apraxia of lid opening.

PURPOSE: To determine whether regional cerebral functional abnormalities exist in patients with apraxia of lid opening (ALO). METHODS: Cerebral glucose metabolism was examined by positron emission tomography (PET) in 11 patients (8 women and 3 men, age 48-69 years); 10 with ALO accompanied by blepharospasm and 1 patient with pure ALO. Eleven normal volunteers (6 women and 5 men, age 45-66 years) were examined as controls. A comprehensive ophthalmological examination, magnetic resonance imaging (MRI), and PET were performed. The cerebral glucose metabolism was evaluated by the relative uptake of [fluorine-18]fluorodeoxyglucose by PET. The mean +/- two standard deviations of the normal controls was defined as the normal range for cerebral glucose metabolism. RESULTS: MRI revealed no particular lesion except for an infarction in the unilateral basal ganglia in two patients. Decreased glucose metabolism was observed in a wide area of the medial frontal lobe (six cases) and primary visual cortex (PVC) (four cases). Group multiple comparisons revealed a significant decrease ( P<0.0035) in the bilateral anterior cingulate gyrus, left supplementary motor area (SMA), and bilateral PVC. CONCLUSION: The results support the hypothesis that ALO is associated with hypofunction in the SMA and/or anterior cingulate gyrus.

Clinical findings in Japanese patients with Waardenburg syndrome type 2.

PURPOSE: To determine the visual characteristics of Japanese subjects with the Waardenburg syndrome type 2. METHODS: The visual functions of 11 albino patients who were identified from the screening of 240 children attending a school for children with a hearing deficit were studied. The ophthalmological examinations included eye position, visual acuity, biomicroscopy, ophthalmoscopy, visual field by confrontation or Goldmann's perimetry, stereoacuity by the Titmus test, and color vision by the Ishihara pseudoisochromatic plates. RESULTS: A combination of congenital sensory deafness and partial ocular albinism without lateral displacement of the lacrimal puncta was observed in 11 (4.6%) of the students with hearing deficit. All these children had sectorial heterochromia irides with local retinal hypopigmentation. Lid deformities were not present. The retinal vasculature was normal, and macular hypoplasty was not found. Other than 1 eye with hyperopic amblyopia, no serious visual disturbance was found in these patients. CONCLUSIONS: The 11 students were classified as having Waardenburg syndrome type 2. None had a critical visual deficit, and all had partial heterochromia irides and retinal hypopigmentation.