Current research has shown differences in eye gaze, or ocular observing responses amongst individuals diagnosed with autism spectrum disorder (ASD) compared with their typically developing counterparts, and with individuals with developmental disabilities other than autism. Eye gaze is currently studied as a predictor for ASD diagnoses and as a potential predictive level of social deficit for individuals already diagnosed with autism. Deficits in language and communication are also studied as predictive risk factors for ASD, and are identified as areas for treatment for individuals with autism. As a behavior analytic account of language, Relational Frame Theory (RFT) suggests that language development is attributed to the development of derived relational responding repertoires. A growing body of literature suggests that there is great benefit in behavior analytic treatment methods for autism that incorporate procedures rooted in RFT. Specifically, relational training procedures that promote derived relational responding (DRR) have been shown to improve language repertoires for children with autism. Previous research using typically developing adults has also suggested that accuracy in eye gaze on relational tasks improves as individuals demonstrate the emergence of novel derived relations. By combining the benefits of relational training procedures on outcomes of language development with technology used to understand eye gaze behaviors, behavior analysts may be able to better understand how to target specific behaviors in treatment that may indirectly improve eye gaze. In turn, improvements in eye gaze may assist in increasing socially significant and helpful behaviors such as attending to appropriate social stimuli within the environment. The current series of studies investigated the relationship between DRR repertoires and ocular observing responses in individuals with autism. Study 1 examined the relationship between DRR of equivalence relations with latency to respond to task items, as well as eye fixation duration and fixation rate toward correct stimuli in the assessment. The results from this study showed a strong, positive correlation between fixation rate and duration with assessment scores. These results suggest more advanced DRR repertoires lead to longer and more frequent eye gaze toward correct stimuli. Study 2 investigated changes in latency to respond as well as changes rate and duration of eye fixations as participants were taught novel relations and tested for the emergence of derived responding. All four participants in the study demonstrated an increase in fixation to correct stimuli from baseline to treatment. Study 3 sought to evaluate the impact that relational training techniques have on eye gaze following a 6-week intervention period compared to a more traditional treatment technique and a waitlist control. Eye gaze measures were assessed before and after the intervention using three different categories of videos of social situations: Person Telling a Story, Conversations, and Social Imaginative Play. Results suggested that the relational training procedure had the most significant impact on eye gaze for Conversation videos compared to a direct contingency group and a waitlist control group. Taken together, the results suggest the potential impact that RFT-based treatments have on ocular observing responses for children with ASD, and how improvements may benefit appropriate eye gaze toward a social environment.

Aim; This study looks at the effect of orthokeratology on a number of biometric parameters and refractive error in an adult population. Method; Forty three myopic subjects were recruited to a twelve month study into the effects of orthokeratology on ocular biometry and refractive error. Two different back surface lens designs were applied right eye) pentacurve and left eye) aspheric. The aspheric design was chosen to more closely mimic the cornea¿s natural shape. Anterior and posterior apical radii and p-values; corneal thickness and anterior chamber depth were measured using the Orbscan IIz; together with ocular biometry by IOL Master and a standard clinical refraction. All measurements were repeated at one night, one week, one, three, six and twelve months. Refractive changes were analysed against biometric changes. Results; Twenty seven participants completed one month of lens wear. Twelve subjects completed twelve months of lens wear. Subjects with myopia ¿ -4.00DS were successfully treated with orthokeratology. Both anterior and posterior apical radii and p values were altered by orthokeratology. Corneal thickness changes were in agreement with previously published studies. Axial length and anterior chamber depth were unaffected by the treatment. Conclusion; Orthokeratology should be available as an alternative to laser refractive surgery. It is best restricted to myopes of up to -4.00DS with low levels of with the rule corneal astigmatism. The use of an aspheric back design contact lens did not produce a significant benefit over that of a pentacurve.

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<p> This dissertation investigated the importance of information from various sensory receptors on the perception of self-orientation. In five experiments, we systematically manipulated the relative orientation between the gravitational inertial forces and the body. </p> <p> The first experiment was originally designed to evaluate the effect of body inversion on the perception of straight-ahead. Interestingly, when participants were inverted, females presented a greater footward bias in the perception of straight-ahead than males. Two follow-up experiments revealed that whole-body rotation and altered blood-distribution could not explain the gender differences in the perception of straightahead. As a result, we attributed the gender differences in the perception of selforientation to differences in the use of afferent information from stable gravireceptors (i.e., otoliths). </p> <p> A fourth experiment examined the contribution of perceptual strategy to the perception of self-orientation. Once again, females exhibited a greater footward bias than males in the perception of straight-ahead. However, this bias was reduced slightly when female participants were instructed to focus on cues arising from inside the body. This finding indicates that, at least to some extent, strategy mediates gender differences in perceptual decision-making. </p> <p> The final experiment was designed to examine the importance of limb movement on the perception of spatial orientation. Five response modes were used to gradually increase the motor demands associated with perceptual judgments about self-orientation. This study was designed to test a theory of visual information processing (i.e., Milner & Goodale, 1995), which claims that the use of distinct visual processing modules depend on the motor demands of a visual perception task. Interestingly, we found that whole limb movements affect the perception of an egocentric illusion (i.e., oculogravic illusion; see Graybiel, 1952). </p> / Thesis / Doctor of Philosophy (PhD)

No / Amblyopia is the condition in which reduced visual function exists despite full optical correction and an absence of observable ocular pathology. Investigation of the underlying neurology of this condition began in earnest around 40 years ago with the pioneering studies conducted by Hubel and Wiesel. Their early work on the impact of monocular deprivation and strabismus initiated what is now a rapidly developing field of cortical plasticity research. Although the monocular deprivation paradigm originated by Hubel and Wiesel remains a key experimental manipulation in studies of cortical plasticity, somewhat ironically, the neurology underlying the human conditions of strabismus and amblyopia that motivated this early work remains elusive. In this review, the authors combine contemporary research on plasticity and development with data from human and animal investigations of amblyopic populations to assess what is known and to reexamine some of the key assumptions about human amblyopia.

Neste estudo, foram descritos os aspectos clínicos e resultados visuais em indivíduos com evidência sorológica e sinais clínicos de toxoplasmose ocular. Os sujeitos foram examinados com lâmpada de fenda, exame de oftalmoscopia indireta, tendo registros fotográficos com retinografia e tomografia de coerência óptica. Duzentos e sessenta e sete participantes foram incluídos no estudo (n = 350 olhos). A forma de toxoplasmose ocular foi considerada primária em 52 indivíduos (19,5%), recorrente ativa em 89 (33,3%) e inativa em 126 (47,2%). A maioria dos olhos apresentou uma lesão (n=169; 48,3%), enquanto que 149 olhos (42,6%) apresentaram duas a quatro lesões e 32, cinco ou mais lesões (9,1%). As lesões centrais estiveram presentes em 127 olhos (36,3%), periféricas em 178 (50,9%), enquanto que lesões centrais e periféricas em 45 (12,6%). A maioria dos indivíduos apresentou sorologia para toxoplasma gondii (T. gondii) IgG + IgM- (n=245; 91,8%), enquanto que apenas 22 (8,2%) foram T. gondii IgG + IgM +. Do total de olhos afetados em que a acuidade visual foi medida (n=314), a maioria (n=160; 50,9%) apresentou melhor acuidade visual corrigida final >20/40, e 25,8% (n=81) foram considerados cegos (<20/400). Lesões múltiplas, de localização central e com tamanho maior que um diâmetro de disco óptico foram consideradas fator de risco para pior prognóstico visual. A membrana epirretiniana (n=21; 7,1%) e opacidade vítrea (n=20; 6,8%) foram as principais causas de complicações observadas. A taxa de incidência de complicações foi de 0,41 complicações/ano, e foram verificadas 0,13 reativações/ano. O estudo demonstrou altas taxas de déficit visual, devendo ser realizados novos estudos para o desenvolvimento de novas modalidades terapêuticas para diminuir o impacto da doença como causa de cegueira e deficiência visual. / In this study, we describe the clinical aspects clinical aspects and visual outcomes in individuals with serological evidence and clinical signs of ocular toxoplasmosis. The subjects were examined with a slit lamp, indirect ophthalmoscopy examination, having photographic records with retinography and optical coherence tomography. Two hundred and sixty -seven subjects were included in the study (n=350 eyes). The form of ocular toxoplasmosis was considered primary active in 52 subjects (19.5%), recurrent active in 89 subjects (33.3%) and inactive in 126 (47.2%). Most eyes presented only one lesion (n=169; 48.3%), whereas 149 individuals (42,6%) had 2-4 lesions, and 32 had five or more lesions (9.1%). Central lesions only were present in 127 eyes (36,3%), peripheral in 178 (50,9%%), while concomitant central and peripheral were present in 45 (12.6%). Most subjects had T. gondii IgG+ IgMserology (n=245; 91.8%), whereas only 22 (8,2%) were T. gondii IgG+ IgM+. From the total of affected eyes which visual acuity was measured (n=314), most (n=160; 50,9%) had better final corrected visual acuity> 20/40 and 25.8% (n = 81) were considered blind (<20/400). Multiple, centrally located lesions of greater size than an optic disc diameter were considered risk factor for a worse visual prognosis. The epiretinal membrane (n=21; 7.1%) and vitreous opacity (n=20; 6.8%) were the main causes of complications seen. The incidence rate of complications was 0,41 complications/year, and it was verified 0,13 reactivations/year. The study demonstrated a high rate of visual impairment, and studies for the development of novel therapeutic modalities should be performed to reduce the impact of the disease as a cause of blindness and visual impairment.

A prevalência mundial da hanseníase vem demonstrando redução no número de casos, porém, no Brasil e em alguns países, ela ainda representa um grave problema de saúde pública, podendo levar a incapacidades funcionais graves como a cegueira. O objetivo do estudo foi avaliar a relação entre as alterações do piscar e a superfície ocular em hansenianos. Todos os pacientes estudados foram submetidos à mesma anamnese e avaliação oftalmológica: acuidade visual, ectoscopia, biomicroscopia, avaliação da superfície ocular, teste da graduação da força muscular do orbicular, sensibilidade corneana, distância da margem reflexa, medida da pressão intraocular e mensuração do piscar espontâneo palpebral por meio de um método de imagem por vídeo. Dos 56 pacientes examinados, 69,6% eram do sexo masculino, com média de idade de 55,96 ± 16,63 dp, 46,4% se declararam negros e 28,55% pardos, 71,4% apresentavam a forma multibacilar e 73,2% estavam fora do registro ativo da doença. Desses 56 pacientes, 43 apresentaram significativa simetria interocular no acometimento do nervo facial e do trigêmeo (p=0,11), o que foi corroborado pela alta correlação entre as medidas da amplitude do piscar entre os olhos (r=0,90). Apenas 12,5% apresentaram tempo de ruptura do filme lacrimal menor que 10 segundos e em um paciente este foi menor que 5. Evidenciou-se sofrimento da superfície ocular em cerca de 14% dos olhos. As alterações de sensibilidade foram mais prevalentes, pois 51,8% apresentaram algum grau de diminuição. A média geral da taxa do piscar foi de 17,0 ± 2,6 blink/min. De acordo com o exame de Lissamina, observou-se taxa média de 16,0 ± 2,8 (média±dp) para os pacientes com resultado negativo e 23,2 ± 6,8 para os com resultado positivo (t=0,961; p=0,3407); e em relação à sensibilidade corneana, as taxas médias foram 14,6 ± 3,8 e 19,2 ± 3,6 para os pacientes com resposta imediata e alterada, respectivamente (t=0,875; p=0,3857). De acordo com o tônus muscular, a média das taxas do piscar para os pacientes normais e alterados não foi significativa (t=0,539; p=0,592). Apesar do número e da amplitude dos movimentos serem diferentes, a main sequence demonstrou comportamento linear em todos os casos, sendo a média geral 20,25 ± 6,9 (0,94 ep). As médias da taxa, amplitude e efetividade do piscar em pacientes com função do músculo orbicular do olho normal e naqueles com função alterada não demonstraram diferença estatística, já a média da velocidade máxima do piscar com função normal foi de 115,5 ± 47,2 mm/s, enquanto que naqueles com lagoftalmo foi 67,7 ± 27 (t=2,08; p=0,04) e a média do deslocamento horizontal de 2,1 ± 0,7 mm e 0,9 ± 0,8 mm, respectivamente (t=1,99; p=0,05). Embora os pacientes hansenianos não apresentem taxa de piscar diferente do normal, demonstram tendência à diminuição da velocidade e do deslocamento horizontal quando apresentam alterações da função do músculo orbicular. A maioria dos pacientes apresentou alteração de sensibilidade corneana, porém, sem sinais de sofrimento da superfície ocular, principalmente com a cinemática palpebral preservada. / Global prevalence of leprosy has demonstrated a reduction in the number of cases, however, in Brazil and some countries, it still represents a serious public health problem, often leading to severe functional disabilities such as blindness for example. This study aimed to evaluate the relationship between blink and ocular surface in patients with leprosy. Leprosy patients underwent the same history and ophthalmologic evaluation: visual acuity, ectoscopy, slit lamp examination, evaluation of ocular surface, test the eyelid function and the degree of orbicularis function, corneal sensitivity, margin reflex distance, measured intraocular pressure and measuring eyelid spontaneous blinking through an image video system. 69.6% were male, with a mean age of 55.96 ± 16.63 SD. 46.4% declared themselves as black and brown were 28.55%, 71.4% were multibacillary and 73.2% were out of active disease registry. Between the 56 patients examined, 43 of those had significant interocular symmetry of the involvement of the facial and the trigeminal nerves (p=0.11), which was confirmed by the high correlation between the measurements of amplitude flashing of the eyes (r=0,90). Only 12.5% had TFRL was under 10 seconds and in one patient it was under 5 seconds. It was evidenced suffering from ocular surface in about 14% of the eyes. Sensitivity changes were more prevalent, 51.8% had some degree of impairment. Overall average blink rate was 17.0 ± 2.6 blinks/min. In the lissamine test, we observed an average rate of 16.0 ± 2.8 for patients with negative and 23.2 ± 6.8 for a positive result (t=0.961, p=0.3407). The mean values were 14.6 ± 3.8 (mean ± SD) and 19.2 ± 3.6 for for patients with immediate corneal sensitivity response and altered response, respectively (t=0.875, p=0.3857). According muscle tone, mean blink rates for normals and for injured patients, were not different (t=0.539, p=0.592). Although the number and range of motion are different, the main sequence had a linear behavior in all cases, with an overall mean 20.25 ± 6.9 (p 0.94). The mean blink rate, amplitude and effectiveness in patients with normal orbicularis function and those with altered function, showed no statistical diference, while the mean of maximum velocity blink was, with normal function, 115.5 ± 47.2 mm/s, while those with lagophthalmos was 27 ± 67.7 (t=2.08, p=0.04) and the mean horizontal displacement was 2.1 ± 0.7 mm and 0.9 ±0.8 mm respectively (t=1.99, p=0.05). Although leprosy patients do not have a different flash rate of the normal population, blinking characteristics show a tendency to decrease in speed and horizontal scrolling when they show important changes in orbicularis function. The vast majority of patients had corneal sensitivity changes, but without signs of ocular surface suffering, especially those with eyelid kinematics preserved.

As próteses oculares têm a função de restabelecer a estética simultaneamente à manutenção da forma anatômica da cavidade orbital, preservando o tônus muscular palpebral e inibindo o colapso palpebral. Como poucos trabalhos científicos foram realizados para avaliar a recuperação de tônus muscular em indivíduos com necessidade de próteses oculares, este trabalho teve o objetivo de quantificar, por meio da eletromiografia, essa qualidade muscular e observar a atividade dos músculos óculo motores em pacientes não reabilitados, reabilitados e controle. A atividade eletromiográfica foi captada durante os repousos inicial e final e atividades que envolveram efetiva participação da musculatura nas seguintes condições clínicas: abertura e fechamento normais das pálpebras e abertura e fechamento forçados das pálpebras. Diante dos resultados apresentados nesse estudo, observou-se que a prótese ocular individualizada não interfere nos músculos óculo motores da hemiface contralateral à reabilitada; o contato da prótese ocular nos tecidos musculares remanescentes da cavidade anoftálmica realiza efeito mioestimulador e tanto no grupo reabilitado como no grupo controle, houve maior atividade eletromiográfica nos músculos orbiculares inferiores na ação de abertura e fechamento. / The ocular prosthesis is meant to restore the aesthetics while maintaining the anatomical shape of the orbital cavity, preserving the eyelid muscle tone by inhibiting the breakdown of the eyelid. As few scientific studies were conducted to evaluate the recovery of muscle tone in individuals that need ocular prosthesis, this study aimed through electromyography evaluate this muscle quality and observe the activity of eye muscles in patients not rehabilitated, rehabilitated and control. Electromyographic activity was captured during initial and final rest positions and activities involving active participation of muscles in the following clinical conditions: normal opening and closing eyelid and forced opening and closing eyelid. From the results presented in this study, it was concluded that the ocular prosthesis does not interfered in individual ocular motor muscles of the rehabilitated contralateral hemiface; the ocular prosthesis contact on the remaining tissue of the anophthalmic cavity did myostimulator effects, in the rehabilitated and control groups, EMG activities were greater in lower orbicular muscles at opening and closing actions.