Asymptomatic idiopathic intracranial hypertension in children.

OBJECTIVE: To define characteristics of pediatric asymptomatic idiopathic intracranial hypertension (IIH). PATIENTS AND METHODS: We retrospectively reviewed our Neuro-Ophthalmology database (2000-2006) for all cases of symptomatic and asymptomatic pediatric IIH. RESULTS: Out of 45 IIH cases, 14 (31.1%) were asymptomatic (incidental examination). When compared with children with symptomatic IIH, asymptomatic cases were younger [5.6 (1.8-15) vs 11.0 (5-17) years, P = 0.007], had lower percentage of obesity (14.3% vs 48.4%, P = 0.046), and had male predominance (71.4% vs 38.7%, P = 0.06). Asymptomatic cases required shorter duration of acetazolamide treatment [3 (0-8), vs 6 (0-20) months, P = 0.021], and resulted in complete resolution of swollen discs. CONCLUSIONS: We speculate that asymptomatic IIH may be more common in young children and could represent a milder form or a presymptomatic phase before evolving into classic symptomatic IIH. Further studies to assess the clinical significance of asymptomatic IIH are warranted.

Selective fovea-related deprived activation in retinotopic and high-order visual cortex of human amblyopes.

Amblyopia is a visual disorder starting at early childhood and characterized by reduced visual acuity not of optical origin or due to any eye disease. One expression of such an anomalous early visual experience is abnormal foveal vision. In a previous fMRI study, faces that were presented to amblyopic eyes evoked little response compared to houses in high-order visual areas. Patients also demonstrated reduced recognition of facial expression, raising the possibility that these face-selective abnormalities are related to foveal vision deficit. Whether this deficit originates in low-level processing or is mediated by compromised activation in high-order visual areas is unresolved. In the present functional magnetic resonance imaging (fMRI) study, we explored the impact of amblyopia on the representation of object images presented in foveally biased central versus peripheral retinotopic eccentricities through manipulation of object size. Small and large pictures were correlated to visual acuities of 6/6 and 6/60, respectively. In low-level visual areas, the amblyopic eye showed significantly reduced activation for centrally placed, small pictures than the sound eye, while activation to large pictures was only slightly reduced. Similarly, in high-order visual areas, the amblyopic eye showed marked reduction in activation in the fusiform gyrus, with normal activation in the collateral sulcus. The center/periphery size-related amblyopic outcomes of this study support a "bottom-up" nature of the center-periphery effect observed in high-order visual areas. Taken together, these findings point to the regional extent and functional selectivity of fovea-related cortical reorganization that is related to abnormal visual development of one eye.

Area-specific amblyopic effects in human occipitotemporal object representations.

The role of early visual experience in the establishment of human high-order visual areas is poorly understood. Here we investigated this issue using human amblyopia--a developmental visual disorder, which manifests a central vision (acuity) deficit. Previous fMRI studies of amblyopes have described abnormal functional activations in early retinotopic areas. Here we report the surprising finding of a selective object-related abnormality in high-order occipitotemporal cortex. Specifically, we found that face-related cortical areas show a severe disconnection from the amblyopic eye, while building-related regions remain essentially normal. The selectivity of the deficit highlights the differential computations performed in the different object-related areas and is compatible with the suggested association of face regions with analysis of fine detail.

Presumed ocular myasthenia and micropsia. A case report.

A 68-year-old woman presented with diplopia. Fluctuations of dysfunction of lateral rectus muscles in both eyes were detected on consecutive examinations. The diagnosis of ocular myasthenia was proposed. After the initiation of therapy, the patient complained of disturbing micropsia. The micropsia and diplopia were relieved by occlusion of one eye or by a base-out prism over one of the patient's eyeglass lenses. Mechanisms of micropsia are discussed.

Influence of the time interval between instillation of two drops of cyclopentolate 1% on refraction and dilation of the pupil in children.

PURPOSE: Because the usual length of time to instill two drops of cyclopentolate 1% (five to ten minutes) is time-consuming and inconvenient to clinical staff as well as to the child and the child's parents, we investigated the influence of the time interval between the instillation of the two drops on refraction and mydriasis in children. METHODS: We conducted a crossover study on 48 children at the Tel-Aviv Medical Center. Gender, iris color, ethnic origin, and age were recorded. Two cyclopentolate 1% eyedrops were instilled at a one- or five-minute time interval. Retinoscopy was performed and the mydriatic effect was recorded. One week later, the procedure was repeated, this time with a different time interval. RESULTS: The time interval between the instillation of the two drops had no significant influence on retinoscopy results (P = .65 and P = .50 for right and left eyes, respectively) or on pupil dilation (P = .377 and P = .113 for right and left eyes, respectively). CONCLUSIONS: Instilling two drops of cyclopentolate 1% one minute apart is as effective as instilling them five minutes apart.

Atropine cycloplegia: how many instillations does one need?

Atropine is accepted generally as the most efficient cycloplegic agent. Although it is considered a relatively safe drug, toxic local and systemic side effects do occur. The recommended regimen for atropine cycloplegia has been 7 to 10 applications within 3 to 4 days. We compared the cycloplegic effect of four instillations of atropine drops to the effect of eight instillations. The results showed that the cycloplegia obtained after eight instillations was not greater than after four instillations.

Trilateral retinoblastoma.

Retinoblastoma is the most common intraocular malignancy of childhood. Trilateral retinoblastoma is a syndrome characterized by bilateral ocular retinoblastoma in conjunction with an intracranial neuroblastic neoplasm in the pineal body, or in supraseller or parasellar location. We report the case of a three year old girl with trilateral retinoblastoma and review the literature on this subject.

[Use of botulinum toxin in ophthalmology].

We have used botulinum toxin (Oculinum) for the past 2 years to treat strabismus and other ophthalmic conditions. It was effective for blepharospasm and hemifacial spasm, and in producing pharmacological ptosis. There were a few local complications, such as ptosis and diplopia, which disappeared within a few weeks. This is a new treatment modality with specific indications in ophthalmology.