Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2006. / Description based on contents viewed Jan. 24, 2007; title from title screen. Includes bibliographical references (p. 125-129).

Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliography.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Computerised diagnostic testing and computerised vision training (VT) have been developed for the orthoptic management of binocular vision (BV) anomalies in clinical practice. Computerised measurement of BV is assumed to assist accurate diagnosis of BV anomalies because variability of testing resulting from subjective judgements of examiners is eliminated by automatic measurements. Computerised VT is thought to be effective in the treatment of BV anomalies because the computer games used for vision training will enhance the patient's motivation. However, these assumptions were lacking scientific support. This thesis reports a range of studies to investigate the computerised programs of diagnostic testing (HTS-BVA) and vision training (HTS-iNet) in comparison with corresponding traditional approaches, respectively. The first study was to investigate inter-session repeatability of computerised testing on BV functions. The study results showed that computerised testing on measuring near horizontal fusional vergence (FV) and accommodative facility (AF) did not present higher inter-session repeatability than corresponding traditional testing. The second study was a pilot study for a future rigorous randomized clinical trial (RCT) investigating effectiveness of computerised VT as a home-based treatment for convergence insufficiency (CI). The study results showed the subjects with CI demonstrated improvement of near point of convergence (NPC), near base-out FV and symptoms associated with CI after an 8-week treatment regime. The third study, following from the first study, was to investigate whether accommodative responses (AR) are affected by the novel accommodative stimuli used in computerised AF testing. The study results showed the AR might be affected by the colours of accommodative targets and the colour filter used. Especially, the data of accommodative demand of 4 dioptres revealed that blue targets presented poorer AR than red targets, and the targets seen with colour filters presented poorer AR than those seen without colour filters. The fourth study, also following from the first study, was to investigate whether a prolonged near vision task affects measurements made relating to the near FV system, thus contributing to the variability of clinical findings. The study results showed statistically significant changes in NPC and near dissociated phoria. In further sub-group analyses, the subjects with an initially poor NPC (n = 9) presented greater changes in the NPC and near dissociated phoria than the subjects with normal poor NPC (n = 25).Overall, the computerised testing did not show more repeatable BV measurements than the traditional testing. Finally, an RCT is needed to determine if the computerised VT is more effective than placebo computerised VT as a home-based treatment for CI.

Orientador: Clesio Luis Tozzi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-07-24T01:59:34Z (GMT). No. of bitstreams: 1 Nogueira_FernandoMarquesdeAlmeida_M.pdf: 1342586 bytes, checksum: 1ea3ca9c0d0e881478c6cf61f703c197 (MD5) Previous issue date: 1998 / Mestrado

La esclerosis múltiple es una en enfermedad neurodegenerativa, progresiva e inflamatoria del sistema nervioso central, en la cual interaccionan dos entidades clínicas: la inflamación y la neurodegeneración. Esto implica la alteración de capacidades motoras, sensoriales y de coordinación. El sistema visual, por su amplia implicación neurológica, es una de las capacidades más afectadas en el transcurso de la enfermedad. Cuadros clínicos característicos como la neuritis óptica o la oftalmoplejía internuclear han sido ampliamente estudiados por su alta prevalencia. Otras alteraciones como el adelgazamiento de las diferentes capas retinianas, la reducción de la sensibilidad al contraste o la aparición de nistagmo también han sido sobradamente informadas. En cambio, la función binocular no ha sido objeto de tan exhaustivo estudio, probablemente por la porque la sintomatología asociada a un problema binocular no se manifiesta de forma tan grave o incapacitante como en otras capacidades motoras, sensoriales y/o de coordinación. O porque, anomalías en la visión binocular son sutiles y podrían estar enmascaradas porque se evita la realización de tareas visuales como la lectura. Por este motivo, la presente tesis ha fijado como objetivo caracterizar la binocularidad y oculomotricidad mediante la valoración de la capacidad vergencial, las sacadas, la fijación, la sensibilidad macular y la estereopsis. Se han detectado alteraciones en algunas funciones oculomotoras como la fijación en pacientes con EM, describiendo una mayor inestabilidad con un patrón elipsoidal vertical. Pero este hallazgo no se traduce en una alteración de las sacadas verticales, de hecho, son las horizontales las que presentan mayor dificultad para estos pacientes. Además de esto, los pacientes con EM ven reducida la estereopsis y la capacidad de divergir. Y aunque presentan síntomas que podrían ser compatibles con alteraciones binoculares como la insuficiencia de convergencia, los signos clínicos no caracterizan tal afectación. Así pues, la afectación binocular y oculomotora en pacientes con EM es extensa y presenta una gran variabilidad intra-sujeto, al igual que ocurre en el transcurso mismo de la enfermedad a nivel sistémico.

No description available.

No description available.

Yes / Reduced binocularity is a prominent feature of amblyopia and binocular cues are thought to be important for prehension. We examine prehension in individuals with amblyopia when the target-object was flanked, thus mimicking everyday prehension. Methods: amblyopes (n=20, 36.4±11.7 years; 6 anisometropic, 3 strabismic, 11 mixed) and visually-normal controls (n=20, 27.5±6.3 years) reached forward, grasped and lifted a cylindrical target-object that was flanked with objects on either (lateral) side of the target, or in front and behind it in depth. Only 6 amblyopes (30%) had measurable stereoacuity. Trials were completed in binocular and monocular viewing, using the better eye in amblyopic participants. Results: Compared to visual normals, amblyopes displayed a longer overall movement time (p=0.031), lower average reach velocity (p=0.021), smaller maximum aperture (p=0.007) and longer durations between object contact and lift (p=0.003). Differences between groups were more apparent when the flankers were in front and behind, compared to either side, as evidenced by significant group-by-flanker configuration interactions for reach duration (p<0.001), size and timing of maximum aperture (p≤0.009), end-of-reach to object-contact (p<0.001), and between object contact and lift (p=0.044), suggesting that deficits are greatest when binocular cues are richest. Both groups demonstrated a significant binocular advantage, in that in both groups performance was worse for monocular compared to binocular viewing, but interestingly, amblyopic deficits in binocular viewing largely persisted during monocular viewing with the better eye. Conclusions: These results suggest that amblyopes either display considerable residual binocularity or that they have adapted to make good use of their abnormal binocularity.