Assessing amblyopia treatment using multifocal visual evoked potentials.

BACKGROUND: To evaluate the effect of occlusion treatment for anisometropic amblyopia using multifocal visual evoked potentials (mfVEPs). METHODS: The patients for this study comprised 19 patients (mean age 6.05 ± 1.65 years) with anisometropic amblyopia underwent mfVEP analysis using the RETIscan® system before and after occlusion treatment. After dividing the area into six ring areas and four quadrants, we analyzed the amplitudes and latencies of the mfVEPs. RESULTS: The amplitudes of ring 1 (central field) in amblyopic eyes after treatment were significantly higher than those in the other rings (p = 0.001). The mfVEP amplitudes in each of the six rings between amblyopic eyes and fellow eyes at diagnosis and after occlusion treatment showed no significant differences. In quadrant 1 the amplitudes of the amblyopic eyes and fellow eyes were significantly different at the time of diagnosis (p = 0.005), whereas after occlusion treatment there was no significant difference (p = 0.888). The amplitudes for each of the six rings at diagnosis and after occlusion treatment in amblyopic eyes versus fellow eyes showed no significant difference. There were also no differences in the amplitudes in each of the four quadrants at the time of diagnosis and after occlusion treatment in amblyopic eyes versus fellow eyes. No significant difference was found in the comparison of latency values in each of the six rings or in each of the four quadrants at diagnosis and after occlusion treatment in amblyopic eyes versus their fellow eyes. CONCLUSIONS: The amplitudes of quadrant 1 in amblyopic eyes compared with those of the fellow eyes at diagnosis were increased after occlusion treatment. Changes of the difference between amblyopic eyes and fellow eyes in quadrant 1 after occlusion treatment could be a useful, objective method for monitoring improvement in visual acuity.

Extratarsal presentation of chalazion.

PURPOSE: We report a case of atypical, extratarsal chalazion referred with a history of a chronic inflammatory mass found on the edge of the lower eyelid. METHODS: A 3-year-old female developed a small mass on the medial side of the right lower lid in 4-month duration. She was seen by her ophthalmologist and the diagnosis of a chalazion was made. Over the ensuing one month with warm compression, the lesion subsided and the new lesion appeared away from the edge on the lateral eyelid 3 months ago. RESULTS: She underwent surgery and drainage was performed. We found a track, a proof of migration, on the lower tarsal conjunctiva in the medial side of the right eyelid during surgery. CONCLUSIONS: Long-term observation in chalazion may induce migration with tract and express as an atypical chalazion.

The orbital volume measurement in patients with ventriculoperitoneal shunt.

Enophthalmos occurs from the increased bony volume or decreased soft tissue volume in the orbit and can be caused in patients with long-term ventriculoperitoneal (VP) shunt. This study tried to find out the change of orbital volume by measuring the orbital volume before and after operation in adult patients who underwent VP shunt for hydrocephalus. The 2 evaluators measured orbital volume by using ITK-SNAP 2.4 program with double-blind test for computed tomography images before and after operation targeting 36 patients over the age of 18 who underwent VP shunt with pressure-controlled valve from 2003 to 2011. Wilcoxon matched-pairs signed-rank test of GraphPad software was used to statistically analyze the difference in orbital volume change before and after operation. In case of mean pre-op orbital volume of total 36 patients, the right was measured as 23.72 ± 4.65 cm(3), the left as 23.47 ± 4.61 cm(3), the post-op right as 24.67 ± 4.70 cm(3), and the left as 24.18 ± 4.63 cm(3), showing no statistically significant difference (P = 0.106). The mean pre-op orbital volume of 14 people (28 eyes) followed for more than 11 months was 25.06 ± 4.58 cm(3) in the right and 24.4 ± 5.02 cm(3) in the left and the mean post-op orbital volume was 27.0 ± 4.28 cm(3) in the right and 25.76 ± 3.92 cm(3) in the left, showing statistically significant differences in the change of the volume before and after shunt operation (P = 0.0057). In patients who maintain long-term shunt devices after VP shunt, remodeling of matured orbital bone may be caused due to the change in pressure gradient between cranial cavity and orbit and the possible occurrence of resulting secondary enophthalmos by increased orbital volume should be considered.

Oculomotor neuromyotonia with lid ptosis on abduction.

Ocular neuromyotonia is an episodic involuntary contraction of one or more of the extraocular muscles resulting from spontaneous neural discharges of the oculomotor nerve. It is characterized by symptomatic diplopia for the duration of the contraction and occurs either spontaneously or after a sustained eccentric gaze. Although the mechanism of ocular neuromyotonia is not fully understood, primary or secondary aberrant regeneration and consequent ephaptic transmission generally are held to be involved. We report the case of a patient with right oculomotor neuromyotonia accompanied by lid ptosis on abduction of the left eye who was successfully treated with oral carbamazepine.

Foveal retinoschisis misdiagnosed as bilateral amblyopia.

Juvenile foveal retinoschisis is one of the most common causes of bilateral macular degeneration in young boys. School age with accommodative esotropia may develop amblyopia due to late correction of hyperopia. Retinoschisis is hard to diagnose in patient with subtle macula change and hyperopic amblyopia. We report a case of bilateral foveal retinoschisis before and after treatment with topical dorzolamide, which was misdiagnosed as bilateral hyperopic amblyopia. Optical coherence tomography should be considered in diagnostic procedures of children with hyperopic amblyopia.