Absence of the fourth cranial nerve in congenital Brown syndrome.

PURPOSE: To elucidate the aetiology of congenital Brown syndrome. METHODS: Four consecutive patients diagnosed with unilateral congenital Brown syndrome had a comprehensive standardized ocular motility examination. Any compensatory head posture was measured. Brain magnetic resonance imaging (MRI) with regard for the IV cranial nerve (CN) was performed in all patients. Orbital MRI was performed in 2/4 patients, with images acquired in eight directions of gaze and superior oblique (SO) muscle areas compared. RESULTS: CN IV could not be identified bilaterally in two patients, but was absent only on the side of the Brown syndrome in the two other patients. On the normal side, orbital MRI revealed a smaller SO muscle area in upgaze than in downgaze, demonstrating normal actions of this muscle. On the side of the Brown syndrome, the SO area remained the same in upgaze and in downgaze and approximately symmetric to the area of SO in downgaze on the normal side. CONCLUSIONS: These cases add further anatomical support to the theory of paradoxical innervation in congenital Brown syndrome. CN IV was absent in two patients on the side of the Brown syndrome, but without muscle hypoplasia. SO muscle size did not vary in up- and downgaze, which we interpreted as a sign of constant innervation through branches of CN III.

Desenvolupament d'una aplicació per l'Eye Tracker

El treball consisteix en realitzar una aplicació que faci ús de l'Eye Tracker. L'objectiu marcat es realitzar una aplicació que permeti escriure coses a l'ordinador a persones discapacitades fent ús del dispositiu "Eye Tracker". Aquesta aplicació intentarà facilitar les coses a les persones discapacitades pel que fa a l'ús de l'ordinador i s'intentarà que l'aplicació acabi amb una de les limitacions més importants en persones que no poden fer ús de les mans, i per tant, no poden escriure en l'ordinador.

What Was I Thinking? Eye-Tracking Experiments Underscore the Bias that Architecture Exerts on Nuclear Grading in Prostate Cancer.

We previously reported that nuclear grade assignment of prostate carcinomas is subject to a cognitive bias induced by the tumor architecture. Here, we asked whether this bias is mediated by the non-conscious selection of nuclei that "match the expectation" induced by the inadvertent glance at the tumor architecture. 20 pathologists were asked to grade nuclei in high power fields of 20 prostate carcinomas displayed on a computer screen. Unknown to the pathologists, each carcinoma was shown twice, once before a background of a low grade, tubule-rich carcinoma and once before the background of a high grade, solid carcinoma. Eye tracking allowed to identify which nuclei the pathologists fixated during the 8 second projection period. For all 20 pathologists, nuclear grade assignment was significantly biased by tumor architecture. Pathologists tended to fixate on bigger, darker, and more irregular nuclei when those were projected before kigh grade, solid carcinomas than before low grade, tubule-rich carcinomas (and vice versa). However, the morphometric differences of the selected nuclei accounted for only 11% of the architecture-induced bias, suggesting that it can only to a small part be explained by the unconscious fixation on nuclei that "match the expectation". In conclusion, selection of « matching nuclei » represents an unconscious effort to vindicate the gravitation of nuclear grades towards the tumor architecture.

Line bisection by eye and by hand reveal opposite biases

The vision-for-action literature favours the idea that the motor output of an action - whether manual or oculomotor - leads to similar results regarding object handling. Findings on line bisection performance challenge this idea: healthy individuals bisect lines manually to the left of centre, and to the right of centre when using eye fixation. In case that these opposite biases for manual and oculomotor action reflect more universal compensatory mechanisms that cancel each other out to enhance overall accuracy, one would like to observe comparable opposite biases for other material. In the present study, we report on three independent experiments in which we tested line bisection (by hand, by eye fixation) not only for solid lines, but also for letter lines; the latter, when bisected manually, is known to result in a rightward bias. Accordingly, we expected a leftward bias for letter lines when bisected via eye fixation. Analysis of bisection biases provided evidence for this idea: manual bisection was more rightward for letter as compared to solid lines, while bisection by eye fixation was more leftward for letter as compared to solid lines. Support for the eye fixation observation was particularly obvious in two of the three studies, for which comparability between eye and hand action was increasingly adjusted (paper-pencil versus touch screen for manual action). These findings question the assumption that ocular motor and manual output are always inter-changeable, but rather suggest that at least for some situations ocular motor and manual output biases are orthogonal to each other, possibly balancing each other out.

Status of eye lens radiation dose monitoring in European hospitals.

A questionnaire was developed by the members of WG12 of EURADOS in order to establish an overview of the current status of eye lens radiation dose monitoring in hospitals. The questionnaire was sent to medical physicists and radiation protection officers in hospitals across Europe. Specific topics were addressed in the questionnaire such as: knowledge of the proposed eye lens dose limit; monitoring and dosimetry issues; training and radiation protection measures. The results of the survey highlighted that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens protection is crucial. Personnel should be properly trained in how to use protective equipment in order to keep eye lens doses as low as reasonably achievable. Finally, the results also highlighted the need to improve the design of eye dosemeters in order to ensure satisfactory use by workers.

In vivo characterisation of a novel water-soluble Cyclosporine A prodrug for the treatment of dry eye disease.

Cyclosporine A (CsA) has been demonstrated to be effective for the treatment of a variety of ophthalmological conditions, including ocular surface disorders such as the dry eye disease (DED). Since CsA is characterised by its low water solubility, the development of a topical ophthalmic formulation represents an interesting pharmaceutical question. In the present study, two different strategies to address this challenge were studied and compared: (i) a water-soluble CsA prodrug formulated within an aqueous solution and (ii) a CsA oil-in-water emulsion (Restasis, Allergan Inc., Irvine, CA). First, the prodrug formulation was shown to have an excellent ocular tolerance as well as no influence on the basal tear production; maintaining the ocular surface properties remained unchanged. Then, in order to allow in vivo investigations, a specific analytical method based on ultra high pressure liquid chromatography coupled with triple quadrupole mass spectrometer (UHPLC-MS/MS) was developed and optimised to quantify CsA in ocular tissues and fluids. The CsA ocular kinetics in lachrymal fluid for both formulations were found to be similar between 15 min and 48 h. The CsA ocular distribution study evidenced the ability of the prodrug formulation to penetrate into the eye, achieving therapeutically active CsA levels in tissues of both the anterior and posterior segments. In addition, the detailed analysis of the in vivo data using a bicompartmental model pointed out a higher bioavailability and lower elimination rate for CsA when it is generated from the prodrug than after direct application as an emulsion. The interesting in vivo properties displayed by the prodrug solution make it a safe and suitable option for the treatment of DED.

Landmark detection for fusion of fundus and MRI toward a patient-specific multimodal eye model.

Ophthalmologists typically acquire different image modalities to diagnose eye pathologies. They comprise, e.g., Fundus photography, optical coherence tomography, computed tomography, and magnetic resonance imaging (MRI). Yet, these images are often complementary and do express the same pathologies in a different way. Some pathologies are only visible in a particular modality. Thus, it is beneficial for the ophthalmologist to have these modalities fused into a single patient-specific model. The goal of this paper is a fusion of Fundus photography with segmented MRI volumes. This adds information to MRI that was not visible before like vessels and the macula. This paper contributions include automatic detection of the optic disc, the fovea, the optic axis, and an automatic segmentation of the vitreous humor of the eye.

Effective temporary analgesia for severe painful blind eye.

There are various methods of providing pain relief for painful blind eyes. We wish to recommend this effective method of providing temporary analgesia in patients suffering from a severe painful blind eye before undergoing enucleation.

Cultural differences on seeking information: an eye tracking study

The main goal of this research is to investigate how people with different cultural background differ in their interaction style and visual behavior on search engine results pages (SERP), more specifically between groups from the Middle Eastern region vs. Western Europe. We conducted a controlled eye-tracking experiment to explore and evaluate the visual behavior of Arabs and Spaniardusers when scanning through the first page of the search results in Google. Big differences can be observed in the 4 aspects studied: U.A.E. participants stayed on the SERPs for longer, they read more results and they read each snippet in a more complete way than Spaniards. In Spain, people tended to scan the SERP, reading less text on each snippet, and choose a result among the first top rankedones without hardly seeing those in bottom positions.

Management of diplopia secondary to neurosurgical injury of the orbital roof

BACKGROUND: Diplopia related to neurosurgical procedures is often consecutive to oculomotor nerve lesions. We hereby report an oculomotor dysfunction secondary to an orbital roof effraction and its treatment. HISTORY AND SIGNS: Following surgery for a left anterior communicating artery aneurysm, a 45-year-old woman reported vertical diplopia associated with a left orbital hematoma. The diagnosis of third cranial nerve palsy was excluded by orbital imaging which revealed an orbital roof defect with incarceration of the levator palpebrae and superior rectus. THERAPY AND OUTCOME: As neurosurgeons advised against muscle adhesiolysis, diplopia was corrected by a two-step procedure on the oculomotor muscles. We first corrected horizontal and torsional deviations by operating on the healthy eye, before correcting the vertical deviation on the fellow eye. This two-step extraocular muscle surgery allowed restoration of binocular single vision in a useful field of gaze. CONCLUSIONS: Diplopia can occur as a rare orbital complication during neurosurgical procedures. Surgery of extraocular muscles can provide good functional results

Model-based Segmentation and Fusion of 3D Computed Tomography and 3D Ultrasound of the Eye for Radiotherapy Planning

Computed Tomography (CT) represents the standard imaging modality for tumor volume delineation for radiotherapy treatment planning of retinoblastoma despite some inherent limitations. CT scan is very useful in providing information on physical density for dose calculation and morphological volumetric information but presents a low sensitivity in assessing the tumor viability. On the other hand, 3D ultrasound (US) allows a highly accurate definition of the tumor volume thanks to its high spatial resolution but it is not currently integrated in the treatment planning but used only for diagnosis and follow-up. Our ultimate goal is an automatic segmentation of gross tumor volume (GTV) in the 3D US, the segmentation of the organs at risk (OAR) in the CT and the registration of both modalities. In this paper, we present some preliminary results in this direction. We present 3D active contour-based segmentation of the eye ball and the lens in CT images; the presented approach incorporates the prior knowledge of the anatomy by using a 3D geometrical eye model. The automated segmentation results are validated by comparing with manual segmentations. Then, we present two approaches for the fusion of 3D CT and US images: (i) landmark-based transformation, and (ii) object-based transformation that makes use of eye ball contour information on CT and US images.

Decreased intraocular pressure induced by nitric oxide donors is correlated to nitrite production in the rabbit eye.

PURPOSE: To evaluate the effect of intraocular administration of nitric oxide (NO) donors in the rabbit eye on intraocular pressure (IOP), inflammation, and toxicity. METHODS: Intravitreal and intracameral injections of two NO donors, SIN-1 and SNAP, and SIN-1C and BSS were performed. Clinical examination, IOP measurements, protein evaluation in aqueous humor, and histologic analysis of the ocular globes were realized. Nitric oxide release was demonstrated by nitrite production in the aqueous humor and in the vitreous using the Griess reaction. RESULTS: The drastic decrease of IOP, observed after a single NO donor injection, was correlated directly with nitrite production and, thus, to NO release. Injection of inactive metabolite of SIN-1, SIN-1C, which is not able to release NO, did not modulate IOP. When administered in the aqueous humor or in the vitreous, NO did not diffuse from one segment of the eye to another. No inflammation or histologic damage was observed as a result of a single NO donor administration. CONCLUSIONS: Nitric oxide is implicated directly in the regulation of IOP and its acute, and massive release into the rabbit eye did not induce inflammation or other growth toxic effects on the ocular tissues.

The PROM1 mutation p.R373C causes an autosomal dominant bull's eye maculopathy associated with rod, rod-cone, and macular dystrophy.

PURPOSE: To characterize in detail the phenotype of five unrelated families with autosomal dominant bull's eye maculopathy (BEM) due to the R373C mutation in the PROM1 gene. METHODS: Forty-one individuals of five families of Caribbean (family A), British (families B, D, E), and Italian (family C) origin, segregating the R373C mutation in PROM1, were ascertained. Electrophysiological assessment, fundus autofluorescence (FAF) imaging, fundus fluorescein angiography (FFA), and optical coherence tomography (OCT) were performed in available subjects. Mutation screening of PROM1 was performed. RESULTS: The R373C mutant was present heterozygously in all affected patients. The age at onset was variable and ranged between 9 and 58 years, with most of the individuals presenting with reading difficulties. Subjects commonly had a mild to moderate reduction in visual acuity except for members of family C who experienced markedly reduced central vision. The retinal phenotype was characterized by macular dystrophy, with retinal pigment epithelial mottling in younger subjects, progressing to typical BEM over time, with the development of macular atrophy in older patients. In addition, all members of family C had typical features of RP. The electrophysiological findings were variable both within and between families. CONCLUSIONS: Mutations in PROM1 have been described to cause a severe form of autosomal recessive RP in two families of Indian and Pakistani descent. The results of this study have demonstrated that a distinct redundant PROM1 mutation (R373C) can also produce an autosomal dominant, fully penetrant retinopathy, characterized by BEM with little inter- and intrafamilial variability, and retinal dystrophy with variable rod or rod-cone dysfunction and marked intra- and interfamilial variability, ranging from isolated maculopathy without generalized photoreceptor dysfunction to maculopathy associated with very severe rod-cone dysfunction.

Accurate memory for object location by individuals with intellectual disability: Absolute spatial tagging instead of configural processing?

Using head-mounted eye tracker material, we assessed spatial recognition abilities (e.g., reaction to object permutation, removal or replacement with a new object) in participants with intellectual disabilities. The "Intellectual Disabilities (ID)" group (n=40) obtained a score totalling a 93.7% success rate, whereas the "Normal Control" group (n=40) scored 55.6% and took longer to fix their attention on the displaced object. The participants with an intellectual disability thus had a more accurate perception of spatial changes than controls. Interestingly, the ID participants were more reactive to object displacement than to removal of the object. In the specific test of novelty detection, however, the scores were similar, the two groups approaching 100% detection. Analysis of the strategies expressed by the ID group revealed that they engaged in more systematic object checking and were more sensitive than the control group to changes in the structure of the environment. Indeed, during the familiarisation phase, the "ID" group explored the collection of objects more slowly, and fixed their gaze for a longer time upon a significantly lower number of fixation points during visual sweeping.