Modalities of reading acquisition in three siblings with infantile-onset saccade initiation delay (Cogan congenital ocular motor apraxia): A longitudinal study.

This study aims to ascertain the impact of congenital ocular motor apraxia (COMA), alternatively called infantile-onset saccade initiation delay (ISID), on reading acquisition. More specifically, the consequence of defective initiation of horizontal saccades during reading acquisition was investigated. Three siblings (A: male, 11y3m at the first time-point of testing (i.e. T1 hereafter); B: female, 7y3m at T1 and C: male, 5y9m at T1) suffering from ISID were assessed longitudinally over 3 years in various reading tests and their eye movements simultaneously registered. At each time-point, they were compared to control participants matched on reading level. Eye movements during reading tasks were markedly abnormal in children with ISID at the beginning of reading acquisition and their reading scores were poor. With time, the number of fixations, small amplitude saccades and their reading abilities became comparable to those of control children. Despite the abnormal eye movements and difficulties in specifically directing the eyes to the appropriate position, children with ISID do not seem to encounter major difficulties during reading acquisition, although mild delays might be observed during the early stages.

Can a Specific Computed Tomography-Based Assessment Predict the Ophthalmological Outcome in Pure Orbital Floor Blowout Fractures?

The aim of this study was to determine the predictive value of a specific computed tomography (CT)-based assessment for the final functional ophthalmological outcome in pure orbital floor blowout fractures. Data of 34 consecutive patients with pure blowout fractures who had undergone a period of at least 6 months of medical and ophthalmological follow-up were analyzed. The following 3 CT scan-based parameters were included: area ratio of the fractured orbital floor (RF), maximum height of periorbital tissue herniation (MH), and a 4-grade muscular subscore (MSS) describing the inferior rectus muscle displacement relative to the orbital floor level. The orthoptic complications (diplopia, enophthalmos, and ocular motility restriction) were evaluated by an experienced strabologist. The CT parameters' predictive value was analyzed using receiver operating characteristic curves and area under the curve (AUC), logistic regression, and Spearman correlation.The RF had a significant predictive value for enophthalmos appearance (AUC = 0.75, P = 0.02), and MH for diplopia (AUC = 0.80, P = 0.03). Among patients with complications, the relevance of MSS and MH as well as the severity of vertical deviation were also clinically strongly associated (rho = -0.52 and -0.56).Our study revealed the significantly predictive value of RF for occurrence of enophthalmos and of MH for diplopia persistence. Although statistically unable to predict the occurrence of ocular motility restriction, MH and MSS were clinically strongly correlated with the severity of ocular deviation limitations.

Orthoptic Sequelae Following Conservative Management of Pure Blowout Orbital Fractures: Anecdotal or Clinically Relevant?

The aim of this study was to prospectively assess the prevalence of orthoptic anomalies following conservative management of pure blowout orbital fractures and to evaluate their clinical relevance. Clinical and radiologic data of patients with unilateral conservatively managed pure blowout orbital fractures with a minimum follow-up of 6 months were reviewed. Eligible patients were contacted and invited to undergo an extended ophthalmologic examination as follows: distance and near visual acuities, Hertel exophthalmometry, corneal light reflex (Hirschberg test), ductions and versions in the 6 cardinal fields of gaze, eye deviation with prisms and alternate cover test in all of the 9-gaze directions with Maddox rod, degrees of incyclo/excyclotorsion with right and left eye fixation, horizontal and vertical deviation with Hess-Weiss coordimetry, degree of horizontal/vertical and incyclo/excyclotorsion deviation with Harms wall deviometry, and vertical deviation with Bielschowsky head-tilt test. Of the 69 patients contacted, 49 declined to participate given that they were asymptomatic. Twenty patients agreed to undergo the examination. One patient complained of minimal double vision limited to the extreme downgaze. Four patients had asymptomatic ocular motility disturbances limited to the extreme gaze. Seven patients had asymptomatic horizontal heterophoria. These disturbances did not interfere with daily or professional activities in any of the patients. The current study demonstrated that conservative management of pure orbital blowout fractures can result in orthoptic anomalies. These sequelae were restricted to a very limited portion of the binocular field of the vision and were not found to be clinically relevant.

Endogenous endophthalmitis in a patient with diabetes and foot osteomyelitis.

Endogenous endophthalmitis is a rare condition caused by the hematogenous spread of microorganisms from a remote infection site to the eye. Common predisposing conditions are intravenous drug abuse, diabetes, malignancy, immunosuppression, chronic renal failure, parenteral nutrition or invasive medical procedures. We describe a case of endogenous endophthalmitis in the setting of foot osteomyelitis in a patient with diabetes. A high index of clinical suspicion is required to diagnose this condition early in a patient with diabetes because visual symptoms commonly may be misattributed to retinopathy. Early diagnosis is important.

Primary leptomeningeal melanocytosis in a 10-year-old girl: a challenging diagnosis with a poor prognosis.

Primary leptomeningeal melanocytosis is rarely encountered in the pediatric population. Despite being considered a nonmalignant condition, it uniformly carries a poor prognosis given the ineluctable progression of meningeal infiltration. The case of a previously healthy 10-year-old girl who was first thought to suffer from recurrent hemiplegic migraine is reported. She later developed insidious subacute hydrocephalus. Meningeal biopsy performed during shunt insertion demonstrated an unexpectedly large number of melanocytes consistent with meningeal melanocytosis. Subsequently, the child developed recurrent shunt dysfunction and showed evidence of malignant transformation. The steps to reaching the proper diagnosis are discussed, and the current literature on this rare clinical entity as well as on related central nervous system melanocytic lesions that can occur in the pediatric population is reviewed.

MRI with fibre tracking in Cogan congenital oculomotor apraxia.

BACKGROUND: Congenital ocular motor apraxia (COMA) occasionally shares with Joubert syndrome (JS) and related disorders (JSRDs) a peculiar malformation, the 'molar tooth sign' (MTS). In JSRDs, the absence of superior cerebellar peduncles (SCP) decussation is reported. OBJECTIVE: To investigate whether COMA demonstrates similar abnormal axonal pathways. MATERIALS AND METHODS: Eight healthy age-matched controls, three children with clinical COMA and one child with clinical JSRD underwent examination with a 1.5-T MRI scanner. Diffusion-weighted imaging (DWI), colour-coded fractional anisotropy maps and three-dimensional diffusion tensor imaging (DTI) tractography of the cerebellorubral network were analyzed. RESULTS: On DTI cartography, the 'red dot' originally supposed to represent the SCP decussation in the midbrain was present in controls as well in those with COMA but absent in the single case with JS. In none of the subjects including controls was 3-D FT able to depict the SCP decussation. When seeded, the red dot resulted in the ventral tegmental decussation (VTD). It was normal in controls and in patients with COMA but was absent in our single patient with JSRD. MTS was identified in alla patients with COMA and in the patient with JSRD. CONCLUSION: MTS can be present in both COMA and JSRD but the underlying anatomy depicted by fibre tracking is distinct. The main difference is the integrity of the VTD in COMA.

Ischemic retinopathy and neovascular proliferation secondary to shaken baby syndrome.

BACKGROUND: Ocular lesions known to occur after shaken baby syndrome (SBS) are epiretinal, intraretinal, and subretinal hemorrhages, which are present in up to 100% of patients. Retinoschisis and retinal folds have also been described. We describe three patients with SBS who presented with tractional retinal detachments secondary to neovascular proliferation and discuss the role of ischemia at the retinal level. PATIENTS: Three patients (two 4-month-old babies and one 4-year-old child) with a history of SBS in the first year of life presented with tractional retinal detachment due to severe preretinal fibrovascular proliferation. Peripheral retinal ischemia and vascular disorganization were noted during clinical examination. CONCLUSION: Although physiopathology of SBS remains disputed, ischemia has been accepted as the main feature of cerebral lesions. Ischemia could also be present at the retinal level as suggested by our patients' presentation. It could be induced by direct vitreous shearing of the capillary network or more probably by vascular leak due to brain edema and hypoxic damage of capillaries. Long-term ocular follow-up is necessary in SBS to treat these patients preventively.

Simulation of artificial vision: II. Eccentric reading of full-page text and the learning of this task.

Reading of isolated words in conditions mimicking artificial vision has been found to be a difficult but feasible task. In particular at relatively high eccentricities, a significant adaptation process was required to reach optimal performances [Vision Res. 43 (2003) 269]. The present study addressed the task of full-page reading, including page navigation under control of subject's own eye movements. Conditions of artificial vision mimicking a retinal implant were simulated by projecting stimuli with reduced information content (lines of pixelised text) onto a restricted and eccentric area of the retina. Three subjects, naïve to the task, were trained for almost two months (about 1 h/day) to read full-page texts. Subjects had to use their own eye movements to displace a 10 degrees x 7 degrees viewing window, stabilised at 15 degrees eccentricity in their lower visual field. Initial reading scores were very low for two subjects (about 13% correctly read words), and astonishingly high for the third subject (86% correctly read words). However, all of them significantly improved their performance with time, reaching close to perfect reading scores (ranging from 86% to 98% correct) at the end of the training process. Reading rates were as low as 1-5 words/min at the beginning of the experiment and increased significantly with time to 14-28 words/min. Qualitative text understanding was also estimated. We observed that reading scores of at least 85% correct were necessary to achieve 'good' text understanding. Gaze position recordings, made during the experimental sessions, demonstrated that the control of eye movements, especially the suppression of reflexive vertical saccades, constituted an important part of the overall adaptive learning process. Taken together, these results suggest that retinal implants might restore full-page text reading abilities to blind patients. About 600 stimulation contacts, distributed on an implant surface of 3 x 2 mm2, appear to be a minimum to allow for useful reading performance. A significant learning process will however be required to reach optimal performance with such devices, especially if they have to be placed outside the foveal area.