Bilateral orbital preseptal cellulitis after combined adenotonsillectomy and strabismus surgery--case report and pathogenetic hypothesis.

The first case of bilateral orbital preseptal cellulitis complicating combined adenotonsillectomy and strabismus surgery is reported. The issues of antimicrobial prophylaxis are discussed. The authors speculate about the possible routes of surgical site infection. Transient bacteraemia secondary to adenotonsillectomy may be theoretically a source of distant surgical site infection to the orbit, raising the issue of distant surgical site contamination during multidisciplinary surgery. Combined adenotonsillectomy and eye surgery might benefit from prophylactic systemic antibiotic administration.

Saccadic characteristics in autistic children.

Some studies suggest that individuals with autism present abnormal saccadic eye movements due to an altered strategy for exploration of the surrounding environment. In this study, potential early abnormalities of saccadic movements were explored in 14 male children with autism (5- to 12-year-olds) and in 20 age matched normal males. Only one patient showed clear abnormalities of the "main sequence"; all the other patients, although showing slight changes in saccadic eye movements, did not present classic deficits. Therefore our results did not confirm the presence of saccadic movement alterations in the early stage of autism. Nonetheless, tracts of saccadic initiation failure, continuous changes in saccadic velocity profiles, and instability of fixation were often observed in the autistic population. These findings could be the expression of an early brainstem impairment in autism.

Saccadic analysis for early identification of neurological involvement in Gaucher disease.

The early identification of a neurological involvement in Gaucher's Disease (GD) is essential for a correct dosage of the enzymatic therapy. The saccadic eye movement characteristics of 15 patients affected by the non-neurological GD form show normal peak velocity values and some slight alterations of the velocity profiles present in more than 70% of the recorded eye movements in four cases; two of them later developed epilepsy. This fact supports the hypothesis that the presence of alterations in the velocity profile of the most part of saccadic movements is an index of initial neurological involvement. Further evaluations are necessary in order to understand if an increase of therapy dose should be used in all the subjects presenting such saccadic alterations.

Saccadic parameters for early identification of neuronopathic Gaucher's disease.

For a successful treatment of the neurological form of Gaucher's disease ,an early identification is necessary. Often an alteration of the horizontal saccadic eye movements constitutes the first sign of a central nervous system involvement. In order to obtain an early identification of the neuronopathic forms of the disease, often masked by the use of the enzyme replacement therapy, the classical saccadic characteristics (Latency, Amplitude vs. Duration and Amplitude vs. Peak Velocity relationships) are not usable. This work studies if some other parameters (Mean Velocity/Peak Velocity, Kurtosis, Skewness, Asymmetry), are able to describe the saccadic velocity profiles, could be considered to build an expert system able to reach the aim.

Ocular injuries by elastic cords in children.

BACKGROUND: Elastic cords hitting the eyeball as high-speed projectiles can severely damage ocular structures and can produce permanent visual function impairment. OBJECTIVES: To evaluate the frequency, mechanics, and severity of eye injuries caused by elastic cords in children to adopt the most appropriate preventive measures. METHODS: A retrospective medical records review of hospital admissions secondary to ocular trauma between 1991 and 1997 in a pediatric ophthalmology unit at an urban tertiary care pediatric hospital was performed to select all children admitted for ocular injury caused by an elastic cord. RESULTS: Eight children fulfilled the inclusion criteria; the prevalence ratio was 2% of all pediatric trauma admissions. In all cases the mechanics of trauma was a combination of blunt and high-speed projectile injury. The mechanism of trauma in younger patients was typically a cord that was misused during unsupervised playtime, whereas cord slipping from car roof racks was noted in older patients. One patient suffered a severe permanent visual impairment caused by retinal detachment. All other children regained full visual acuity at the time of discharge and maintained it through a mean follow-up of 22 months (range: 18-29). CONCLUSION: Circumstances of injury in younger children are different from those found in older children, the latter being similar to those reported for adults. Prevention is the primary measure to be taken to reduce the prevalence of this injury and to lower the risk for ocular severe anatomic damage as much as possible. This can be achieved primarily by modifying the design of the hooks, intensifying educational campaigns, and keeping elastic cords out of children's reach.

Cyclopean and disconjugate adaptive recovery from post-saccadic drift in strabismic children before and after surgery.

Post-saccadic drift has been analyzed in strabismic children 11-18 yr old, before and after surgery. Before surgery all the subjects had a large multi-component post-saccadic drift. A disconjugate compensation of the drift was not active, but an optimized cyclopean compensation occurred, aimed at minimizing the drift size in both eyes, either with binocular or monocular vision. The drift was directed toward the static offset of the eyes. One week after surgery the drift increased in most cases but the cyclopean compensation still occurred. One week later, a partial disconjugate compensation decreased the drift to levels lower than before surgery. In one subject surgery produced very big three-component drift, exceeding 20 deg. One year after the drift was decreased to < 1 deg. A mathematical model is presented accounting for most of the results.

Saccadic eye movement conjugation in children.

In recent years the conjugacy of the saccadic eye movements has been studied extensively in adult humans, while little investigation has been carried out in children. We studied the characteristics of binocular saccades in school-age children, finding significant differences with adults, particularly in their dynamics and binocular coordination. The largest deviations were found in the youngest children. An incomplete optimization of the saccadic waveform and a poor disconjugate compensation of the mechanical asymmetries of the plants are hypothesized to explain the results.

[Management of congenital nasolacrimal duct obstruction. Timing of probing]. / Trattamento della dacriostenosi congenita. Quando eseguire il sondaggio delle vie lacrimali.

In the management of congenital nasolacrimal duct obstruction (CNDO), there is not a well-established agreement about the proper time for probing. Some authors perform it prior to the first year of life, since after this age the relapse frequency would be very high; others prefer conservative management, since they deny this high frequency. In order to evaluate which one of these two opinions has to be considered more appropriate, the present study retrospectively reviewed the frequency of relapses at the 6-month-mark after surgery in 77 patients (40 males, 37 females) probed for CNDO at the Children's Hospital of Trieste in the 1990-1992 period. In our case-record relapses were found in 7.8% of all patients (8.8% of eyes), while the corresponding percentages were 10.8% of patients (14.3% of eyes) in those probed in the first year of life, 5% of patients (3.8% of eyes) in those probed after this time. These results show no worsening for late probing outcome, with respect to early probing. As a consequence of these findings, it can be recommended that for CNDO it is proper to start with a conservative management, represented by lacrimal sac massage and antibiotic eye drops instillation, if mucopurulent discharge is present, for a 4-6 weeks period. If symptoms do not disappear completely after this period, whether probing is the treatment of choice, possibly after the 6th month of life, or, when parents prefer this option, to resume the medical treatment, since also late probing guarantees a good outcome. The choice for probing is mandatory after second year of life.

Characteristics of horizontal smooth pursuit eye movements to sinusoidal stimulation in children of primary school age.

Previous research about the maturation of the smooth pursuit system has been carried out in newborns and in human infants in the first months of life. A lower gain was found with respect to adults (where gain is close to 1), with frequent saccadic intrusions. On the contrary, no data are available about smooth pursuit response in children. To fill this gap, we analyse in this study the level of maturation reached by children over 7 yr old (the minimum age in which a correct test can be done). Using a cosinusoidal stimulation, the smooth pursuit characteristics (velocity and position gains and phases) evaluated in children are compared to the corresponding parameters in adults. Our data show a clear difference between the two groups, in particular for velocity gain values (which are lower in children), and a larger variability in children. Since the influence of fatigue and prediction appears to be small, we conclude that these differences can be justified both by high level psychological or cognitive factors and incomplete maturation of smooth pursuit system in children.

Normal intraocular pressure in children.

The age-related trend values and the normal intraocular pressure (IOP) increase curve from birth through the 16th year of life were studied in 460 subjects with a noncontact tonometer (Keeler Pulsair, Keeler, Ltd, Windsor, Berks, UK). Much lower values than in adults were recorded in subjects up to the age of 3 or 4 years. This finding leads us to believe that in the treatment of infantile glaucoma IOP should be kept within the age physiologic levels, in an attempt to prevent visual field loss and optic atrophy.

Some characteristics of saccadic eye movements in children of primary school age.

The characteristics of saccadic eye movements have been extensively studied in adults; researches have also been devoted to the saccades of preschool age children. On the contrary, for primary school-age children no data exist; we investigate the eye movements (recorded utilizing an infrared technique) of six children 7 to 11 years old. The main results indicate that the values of some parameters (for example the saccadic latency and duration) are in the same range as the values of the correspondent parameters in adults, while the values of other parameters (in particular peak velocity and mean velocity/peak velocity ratio) are distinctly different from the ones measured in adult subjects.