Detecting retinal vigabatrin toxicity in patients with partial symptomatic or cryptogenic epilepsy.

PURPOSE: Detecting retinal vigabatrin toxicity in patients with partial symptomatic or cryptogenic epilepsy can be challenging because of preexisting visual field defects secondary to a structural abnormality in the brain or lack of collaboration. The aim of this study was to measure the retinal nerve fiber layer thickness (RNFLT) with optic coherence tomography (OCT), as well as contrast sensitivity, color vision, and perimetry, in patients with partial symptomatic or cryptogenic epilepsy on vigabatrin, and to determine the efficacy of these tests as markers of vigabatrin-related retinal damage in these subgroups of epileptic patients. METHODS: The study involved 38 patients with either partial symptomatic or cryptogenic epilepsy and 16 healthy individuals comprising the control group. At the time of the study, 14 of the patients were using vigabatrin, 10 were receiving sodium valproate monotherapy, and 14 were on carbamazepine monotherapy. All the participants underwent RNFLT imaging with OCT, contrast sensitivity, color discrimination assessment, and perimetry. RESULTS: The average 360 degrees RNFLT of the vigabatrin group was significantly lower when compared to the other groups. The average RNFLT of all quadrants except the temporal one in the vigabatrin group was also significantly reduced. There was no difference in the mean deviation, contrast sensitivity, and color discrimination between the study groups, but they were all significantly lower than the control group. CONCLUSIONS: RNFLT measurement with OCT can efficiently identify vigabatrin toxicity in patients with partial symptomatic and cryptogenic epilepsy. Perimetry, contrast sensitivity, and color discrimination assessment might be inconclusive in these particular subgroups of epileptic patients.

Visual acuity and contrast sensitivity function after accommodative and multifocal intraocular lens implantation.

PURPOSE: To evaluate visual acuities and contrast sensitivities (CS) after accommodative, refractive, and diffractive multifocal intraocular lens (IOL) implantations. METHODS: After cataract extractions, in 20 eyes accommodative IOL (group 1), in 30 eyes refractive IOL (group 2), and in 20 eyes diffractive multifocal IOL (group 3) implantations were performed. CS were measured with the stereo optical functional acuity contrast test. Uncorrected distance (UCDVA) and distance corrected near visual acuities (DCNVA) and refractive values were determined. RESULTS: The mean UCDVA (0.99+/-0.03) and DCNVA (0.98+/-0.04) of group 3 were significantly better than the other IOL groups. The mean DCNVA of group 2 (0.71+/-0.14) was significantly better than group 1 (0.5+/-0.08). One month after the operations CS, values of group 2 were significantly lower than the 2 other IOL groups. Photopic CS values of group 1 at 12 and 18 cycles per degree (cpd) were significantly higher than group 3. Three months after the operations, CS values of group 1 and 3 were significantly higher than that of group 2 at 3, 6, 12, and 18 cpd and in all spatial frequencies respectively. There was no difference between groups 1 and 3 with respect to photopic CS values. Mesopic CS values of group 3 were significantly higher than that of group 1 at 1.5, 3, and 6 cpd. At the 6th and 12th month, CS values of group 3 were similar or better compared to the values of the 3rd month. CONCLUSIONS: The diffractive multifocal IOL resulted in more favorable visual acuities and higher CS values than accommodative and refractive multifocal IOL.