Leslie MacKeen

Ocular phenotypes of three genetic variants of Bardet-Biedl syndrome

Bardet–Biedl syndrome is a genetically heterogeneous multisystem disorder that causes severe visual impairment. Retinitis pigmentosa (RP), hypogonadism, digit and renal anomalies, obesity, and a variable degree of mental retardation characterize the disorder. Eight different loci have been identified on 2q31(BBS5), 3p13 (BBS3), 4q27 (BBS7), 11q13 (BBS1), 14q32 (BBS8), 15q22.3 (BBS4), 16q21 (BBS2), and 20p12 (BBS6). The ocular manifestations of Bardet–Biedl syndrome include an early and severe rod‐cone dystrophy causing legal blindness in the second decade. Features of systemic phenotypic variability were proposed to distinguish patients mapped to either the BBS2, BBS3, or BBS4 loci but no phenotype–genotype correlation has been established for the ocular phenotype. We studied the three original families used for the identification of BBS2, BBS3, and BBS4 loci to define the ocular phenotypes of patients (n = 34) and obligate carriers (n = 32) using clinical examination and electroretinography (ERG). RP was severe and early in all cases. Myopia was associated with BBS3 and BBS4, but not BBS2. One patient with Bardet–Biedl syndrome also had iris and chorioretinal colobomata, features suggestive of Biemond syndrome.

A visual approach to providing prognostic information to parents of children with retinoblastoma

Objective: Parents must rapidly assimilate complex information when a child is diagnosed with cancer. Education correlates with the ability to process and use medical information. Graphic tools aid reasoning and communicate complex ideas with precision and efficiency.

Pupillary reflex dilation and skin temperature to assess sensory level during combined general and caudal anesthesia in children.

Background:  Regional anesthesia causes sympathetic blockade, vasodilation and higher skin temperature in anesthetized dermatomes. Measurement of skin temperature changes might provide a useful estimate of the level of caudal anesthesia in children. Pupillary reflex dilation (PRD) allows estimation of the sensory level during combined general/epidural anesthesia in adults, but has not been assessed in children. This study was designed to evaluate skin temperature and PRD as methods of estimating sensory level in children receiving combined general/caudal epidural anesthesia.

Dynamic documentation of the evolution of retinopathy of prematurity in video format.

INTRODUCTION Serial digital photographic examinations have been combined into a video format, which shows development and evolution of the disease over time. This dynamic format has changed the teaching of retinopathy of prematurity (ROP) by illustrating the subtle changes in the temporal arcade angle and choroidal vascular pattern, which can be observed over time in these videos. METHODS Consecutive weekly or biweekly images were obtained on the same infant and were captured using digital retinal photography (RetCam 120) and then archived on compact discs. Those infants that were most photographic and demonstrative of the evolution of ROP were selected for animation. The optic nerve vessels were aligned and image border blended into the previous image using a layer mask, thus creating an animation of consecutive images. DISCUSSION The videos highlight the evolving features of ROP, such as development of arborized vessels posterior to the ridge, development of Stage 3 lesions, progression of plus disease, choroidal vascular changes accompanying the progression of ROP, dynamic changes in the temporal arcade angle, and regression of disease following last photocoagulation. CONCLUSIONS The documentation of this disease as it evolves and its presentation in video format, using digital retinal photographic technology, has allowed subtle anatomical changes to be visualized and potentially studied. This process highlights a new dimension of the dynamic nature of the disease for those involved in the care of an infant with ROP.

Assessment of extraocular muscles position and anatomy by 3-dimensional ultrasonography: a trial in craniosynostosis patients

PURPOSE To determine whether 3-dimensional ultrasonography (3D US) provides information about anatomy and position of extraocular muscles to better guide surgeons approaching strabismus in patients with craniosynostosis who often have anomalous or absent eye muscles. METHODS The 4 rectus eye muscles were imaged using 3D US for 7 children with craniosynostosis before or after strabismus surgery. Reconstructed 3D images were interpreted as having normal or abnormal anatomy and position, based on comparison with images acquired from 6 normal eyes. Interpretation was validated against the intraoperative findings from strabismus surgery. RESULTS A total of 34 scans from the study group were used for comparison and validation purposes. Accuracy of anatomical assessments was 85% +/- 12% (percentage +/- confidence interval) and of positional assessments was 62% +/- 16%. Sensitivity and specificity of anatomical assessments was 80% +/- 14% and 88% +/- 10%, respectively. Anatomic anomalies detected by 3D US included excessively thick, thin, scarred and fibrotic, and absent muscles. Sensitivity and specificity of positional assessments was 48% +/- 17% and 85% +/- 12%, respectively. Positional anomalies such as muscle displacement off the normal clock hour axis or posteriorly displaced insertion were also detected. CONCLUSIONS The 3D US may have an adjunctive role in determining anatomy and position of rectus muscles in patients with craniosynostosis, although it was more accurate in assessing anatomic features rather than positional features of rectus muscles.