Clinical Classification of Acquired Concomitant Esotropia

Background Classification and management of acquired concomitant esotropia is controversial. We sought to establish a simple clinical classification in order to determine in which cases further investigations in search of underlying pathologies are necessary. Patients and Methods Observational retrospective study of the files of 175 consecutive patients examined in our unit between 2009 and 2018 for acute convergent strabismus. One hundred and nine patients were selected, after exclusion of infantile, incomitant, or mechanical esotropias, residual esotropias, and patients examined on a single occasion. All patients received a complete orthoptic and ophthalmological examination. We grouped the patients according to their common characteristics. Results We established the following categories: 1. Acute esotropia of large angle (20 to 45 prism diopters [PD]), accompanied by mild hyperopia (mean 1.2 D) in children (n = 16) and moderate myopia (mean 3.7 D) in adolescents and adults (n = 13). 2. Decompensated micro-esotropia, which is distinguished from the other categories by the presence of abnormal retinal correspondence (n = 33). 3. Decompensated esophoria, with intermittent deviations of 5 to 30 PD, esotropia being compensated part of the time (n = 25). 4. Esotropia present only at a distance in patients over 50 years of age (n = 20). 5. Small-angle esotropia (< 15 PD) greater at a distance, associated with oculomotor cerebellar syndrome (n = 2). Complementary examinations (MRI or CT scan) were performed on 21 patients, leading to the discovery of a posterior fossa astrocytoma in a 4-year-old boy. Conclusions The recognition of decompensated micro-esotropia and esophoria, as well as distance esotropia of the elderly, avoids unnecessary additional investigations, which are indicated in any type of acute comitant strabismus if associated with any neurological sign or symptom (e.g., headaches, nausea, vertigo, imbalance, poor coordination, nystagmus, or papilledema). In the absence of neurological findings, there is no consensus about the indication of neuroimaging in large-angle acquired concomitant esotropia, but long-term follow-up of patients that do not undergo neuroimaging is strongly recommended in order to identify later occurring intracranial diseases. This is of particular importance with children.

A Geometric Theory Integrating Human Binocular Vision With Eye Movement

A theory of the binocular system with asymmetric eyes (AEs) is developed in the framework of bicentric perspective projections. The AE accounts for the eyeball's global asymmetry produced by the foveal displacement from the posterior pole, the main source of the eye's optical aberrations, and the crystalline lens' tilt countering some of these aberrations. In this theory, the horopter curves, which specify retinal correspondence of binocular single vision, are conic sections resembling empirical horopters. This advances the classic model of empirical horopters as conic sections introduced in an ad hoc way by Ogle in 1932. In contrast to Ogle's theory, here, anatomically supported horopteric conics vary with the AEs' position in the visual plane of bifoveal fixations and their transformations are visualized in a computer simulation. Integrating horopteric conics with eye movements can help design algorithms for maintaining a stable perceptual world from visual information captured by a mobile robot's camera head. Further, this paper proposes a neurophysiologically meaningful definition for the eyes' primary position, a concept which has remained elusive despite its theoretical importance to oculomotor research. Finally, because the horopteric conic's shape is dependent on the AE's parameters, this theory allows for changes in retinal correspondence, which is usually considered preformed and stable.

A Geometric Theory Integrating Human Binocular Vision with Eye movement

A theory of the binocular system with asymmetric eyes (AEs) is developed in the framework of bicentric perspective projections. The AE accounts for the eyeball’s global asymmetry produced by the foveal displacement from the posterior pole, the main source of the eye’s optical aberrations, and the crystalline lens’ tilt countering some of these aberrations. In this theory, the horopter curves, which specify retinal correspondence of binocular single vision, are conic sections resembling empirical horopters. This advances the classic model of empirical horopters as conic sections introduced in an ad hoc way by Ogle in 1932. In contrast to Ogle’s theory, here, anatomically supported horopteric conics vary with the AEs’ position in the visual plane of bifoveal fixations and their transformations are visualized in a computer simulation. Integrating horopteric conics with eye movements can help design algorithms for maintaining a stable perceptual world from visual information captured by a mobile robot’s camera-head. Further, this paper proposes a neurophysiologically meaningful definition for the eyes’ primary position, a concept which has remained elusive despite its theoretical importance to oculomotor research. Finally, because the horopteric conic’s shape is dependent on the AE’s parameters, this theory allows for changes in retinal correspondence which is usually considered preformed and stable.

The Shape of the Sky: The Art of Using Egocentric Stereopsis in the Treatment of Strabismus

A protocol for using stereopsis in the treatment of strabismus is described. Suitable for patients with either normal retinal correspondence (NRC) or anomalous binocular correspondence (ABC), the approach emphasizes the interactions between peripheral/egocentric and central/relative stereopsis in such dichoptic instrumentation as vectograms, digital instrumentation, and 3D movies. The paper then discusses the transfer of appreciation of stereopsis from such artificial dichoptic stereoscopic presentations to consciousness of egocentric and relative stereopsis in natural seeing, emphasizing the art, rather than the science, of treatment.

Paediatric ophthalmology and strabismus

This chapter focuses on paediatric ophthalmology and strabismus. It details the embryology, anatomy, and actions of the extraocular muscles, along with clinical skills that include patient assessment and assessment of visual acuity, binocular vision, and stereopsis, assessment of binocular single vision, and retinal correspondence and suppression. It then discusses amblyopia, the measurement and assessment of ocular deviation, the assessment of ocular movements, Hess charts, and the field of binocular single vision. In addition, it discusses concomitant strabismus (the heterophorias, esotropia, and exotropia), incomitant strabismus, the principles of strabismus surgery, general paediatric development, retinopathy of prematurity, retinoblastoma, congenital cataract, paediatric glaucoma, uveitis in children, phacomatoses, and metabolic and storage diseases.

TEKNIK PEMERIKSAAN PADA MIKROTROPIA

AbstrakMikrotropia merupakan strabismus sudut kecil (kurang dari 5˚) yang disertai dengan ARC dan ketajaman stereopsis yang berkurang atau tidak ada sama sekali. Mikrotropia sering disertai dengan sindroma monofiksasi. Ini ditandai dengan adanya fusi perifer dan supresi di daerah sentral (foveal suppresion scotoma) mata yang mengalami deviasi. Mikrotropia dapat dibagi menjadi dua bentuk yaitu mikrotropia primer (mikrotropia with identity dan mikrotropia without identity) dan mikrotropia sekunder. Pemeriksaan diagnostik pada mikrotropia bertujuan untuk menunjukkan adanya penglihatan binokular perifer tanpa disertai penglihatan binokular sentral pada penderita mikrotropia. Pada makalah ini akan membahas karakteristik klinik dan pemeriksaan mikrotropia.AbstractMicrotropia is defined as strabismus with a small deviation (less than 5˚), combined with Anomalous Retinal Correspondence (ARC) and reduced or absent stereoacuity. Microtropia is often accompanied by monofixation syndrome. It is characterized by peripheral fusion and suppression in the central area (foveal suppresion scotoma) of the misaligned eye. There are two forms of microtropia: primary microtropia (microtropia with identity; microtropia without identity) and secondary microtropia. Diagnostic examination of microtropia aims at demonstrating existence of peripheral binocular vision but no central binocular vision. This paper will discuss about clinical characteristic and diagnostic of microtropia.