Retinal electrophysiological results in patients receiving lamotrigine monotherapy.

PURPOSE: To evaluate the effects on vision in patients receiving lamotrigine (LTG) monotherapy. METHODS: Twenty-four consecutive patients taking LTG for partial seizures were referred for a routine ophthalmologic examination including visual acuity testing, tonometry, slit lamp, and fundus examination. Automated kinetic perimetry, electrooculogram (EOG), and electroretinogram were performed after informed consent was obtained. RESULTS: In 18 patients finally included, the clinical ophthalmologic examination showed no abnormality. Four patients complained of blurring; among them, one patient had a visual field constriction in both eyes, which, however, was of unclear clinical significance (poor compliance) and a reduced light/dark ratio of the electrooculogram. One other patient with blurred vision had a reduced EOG, but the visual field was normal. Two patients had a reduced EOG but no visual symptoms. Considering the whole group of patients receiving LTG therapy, the light/dark ratio of the EOG was reduced in a dose-dependent fashion (p < 0.0001). The electroretinogram was normal in all patients. CONCLUSIONS: No irreversible visual field impairment in patients treated with LTG was encountered, although a dose-dependent retinal toxicity may have been present. The exact cellular mechanism of the electrophysiologic changes in patients taking LTG remain to be explained.

The effect on vision of associated treatments in patients taking vigabatrin: carbamazepine versus valproate.

PURPOSE: To evaluate the effect on visual function of a concomitant antiepileptic drug (AED) in patients treated with vigabatrin (VGB). METHODS: Sixty-four consecutive patients with a history of partial seizures currently treated with VGB with either carbamazepine (CBZ) or valproate (VPA) were examined with automated kinetic perimetry, static perimetry, electrooculogram (EOG), and electroretinogram (ERG). An original device based on kinetic perimetry was developed to quantify the area of perception for each isopter. RESULTS: Fifty-two patients were finally included. The results showed a significant difference in patients treated with VGB-VPA compared with patients treated with VGB-CBZ concerning the mean defect of static perimetry and the peripheral and midperipheral isopter (III 4e and III 1a Goldmann equivalent, respectively) in kinetic perimetry. EOG and ERG results did not differ significantly between the two groups. CONCLUSIONS: The visual impairment due to visual field constriction was more important in patients treated with VGB and VPA compared with patients treated with VGB and CBZ. The origin of this difference between the two associations could not be related to any particular retinal electrophysiologic abnormality.

Resolution of acute acquired comitant esotropia after suboccipital decompression for Chiari I malformation.

PURPOSE: To report a case of acute comitant esotropia successfully treated with suboccipital decompression in a 9-year-old male patient with Chiari I malformation. DESIGN: Interventional case report. METHODS: A 9-year-old male with Chiari I malformation had acute onset of diplopia, headache, and comitant esotropia. RESULTS: About 9 months after suboccipital decompression, diplopia resolved and there was near orthophoria on examination 15 months after surgery. CONCLUSION: In view of our case and after a review of literature, we advocate primary suboccipital decompression to treat acute comitant esotropia in patients with Chiari I malformation. A follow-up period of at least 1 year rather than 6 months seems necessary to assess surgery effects.