Clinical problems in strabismus: the Smith-Kettlewell Eye Research Institute symposium.

The Smith Kettlewell Eye Research Institute (SKERI), celebrating its 50th anniversary in 2014, hosted a symposium to identify the most pressing clinical problems in strabismus and binocular vision. Forty-five experts from around the world shared their perspectives at the San Francisco meeting, held November 6-9, 2012. Prior to the meeting, the organizers (TR, APW, RH, JB, AJ) asked attendees to identify the most pressing clinical problems in strabismus and to discuss them in a workshop-based format. The clinical problems were organized into the following six areas: (1) esotropias; (2) binocular vision: amblyopia, suppression, and diplopia; (3) intermittent exotropia; (4) "oblique dysfunctions"; (5) dissociated vertical deviation (DVD); and (6) new approaches to strabismus management. Herein we highlight of some of the clinical problems discussed at the meeting.

The influence of body position on Bielschowsky's test.

PURPOSE: To investigate the veracity of Jampolsky's statement that Bielschowsky's head tilt test is inverted if performed with the patient in the upside-down position and to interpret its neuromuscular mechanism. METHODS: We present a series of 10 patients selected from a referred sample who were diagnosed with superior oblique paresis. Hypertropia was measured in the primary position, with the head erect and tilted toward both shoulders with the patient in the erect, supine, and upside-down positions. The last position was achieved by hanging the patient upside-down. RESULTS: As expected, our results showed the veracity of Jampolsky's statement. The forced head tilt difference was inverted or significantly decreased when the test was performed in the upside-down position. Moreover, in all patients, Bielschowsky's phenomenon was neutralized in the supine body position, in which hypertropia with the head erect tended to vanish. In 3 patients, it disappeared completely. CONCLUSIONS: This study showed that, in patients with superior oblique paresis, differences in the extent of hypertropia in Bielschowsky's test tended to vanish when the test was performed with the patient in the supine position and invert when it was performed with the patient in the upside-down position.

The influence of body position on Bielschowsky's test / A influência da posição corporal sobre o teste de Bielschowsky

Purpose: To investigate the veracity of Jampolsky's statement that Bielschowsky's head tilt test is inverted if performed with the patient in the upside-down position and to interpret its neuromuscular mechanism. Methods: We present a series of 10 patients selected from a referred sample who were diagnosed with superior oblique paresis. Hypertropia was measured in the primary position, with the head erect and tilted toward both shoulders with the patient in the erect, supine, and upside-down positions. The last position was achieved by hanging the patient upside-down. Results: As expected, our results showed the veracity of Jampolsky's statement. The forced head tilt difference was inverted or significantly decreased when the test was performed in the upside-down position. Moreover, in all patients, Bielschowsky's phenomenon was neutralized in the supine body position, in which hypertropia with the head erect tended to vanish. In 3 patients, it disappeared completely. Conclusions: This study showed that, in patients with superior oblique paresis, differences in the extent of hypertropia in Bielschowsky's test tended to vanish when the test was performed with the patient in the supine position and invert when it was performed with the patient in the upside-down position. .

Objetivo: Investigar a veracidade da suposição de Jampolsky de que o teste de inclinação da cabeça de Bielschowsky invertese caso seja realizado com o paciente de cabeça para baixo, e tentar interpretar o mecanismo neuromuscular envolvido. Métodos: Apresentamos uma série de 10 pacientes portadores de paresia do oblíquo superior. Foi medida a hipertropia dos pacientes na posição primária do olhar e com a cabeça inclinada para cada um dos lados nas posições ereta, supina e de cabeça para baixo. Resultados: Como esperado, nossos resultados confirmaram a suposição de Jampolsky; além disso, e em todos os pacientes, o fenômeno de Bielschowsky foi neutralizado em posição supina. As diferenças da magnitude da hipertropia ao teste de Bielschowsky diminuiram significativamente ou inverteramse quando o paciente foi testado de cabeça para baixo. Conclusões: Este estudo demonstrou que, nos pacientes com paresia do oblíquo superior, a hipertropia evidenciada pelo teste de Bielschowsky tende a desaparecer com o paciente na posição supina e a se inverter quando o teste é realizado com o paciente de cabeça para baixo. .

Sideslip of the medial rectus muscle during vertical eye rotation.

PURPOSE: The kinematics of eye rotation is not entirely elucidated despite two centuries of fascination with the deceptively simple yet geometrically complex nature of the movement. Recently, the traditional view that oculorotatory muscles except the superior oblique muscle exert straight pull on the globe has been challenged by the claim that the muscles also go through a connective tissue pulley-like structure that holds them steady during eye rotation. Although earlier studies failed to observe sideslippage at the posterior part of muscles, a finding supportive of the pulley hypothesis, the conclusions should not be taken as conclusive given short-comings in the techniques used in the studies. METHODS: The authors developed a novel method of image analysis to improve spatial resolution and applied the method for investigating the medial rectus muscle, the entire length of which can easily be identified in magnetic resonance images. RESULTS: Contrary to previous reports, vertical sideslippage was observed at the posterior part of the muscle during vertical eye rotation between two tertiary eye positions. Furthermore, the sideslip varied as a function of horizontal eye position, in accordance with the half-angle rule of Listing's law. CONCLUSIONS: These findings are more consistent with the traditional view of the restrained shortest-path model than with the pulley model and have further implications for basic and clinical understanding of ocular kinematics.