Ultraviolet radiation (UV-R) is an environmental factor known to increase the risk of developing an irreversible opacification of the lens (cataract). Increased irradiance of UV-R to the earth because of depletion of stratospheric ozone is of current concern considering cataract formation. Detailed metabolic information from the cornea, lens and aqueous humour might give valuable knowledge on the biochcemical processes occurring in the eye after exposure to UV-R, and thereby a better understanding of the mechanisms by which UV-R induces cataractogenesis. The purpose of this thesis was to study metabolic effects of exposure to UV-R on the anterior part of the eye. Effects of UV-B (280-315 nm) and UV-A (315-400 nm) on the aqueous humour, cornea and the lens from animal models were investigated by 1H nuclear magnetic resonance (NMR) spectroscopy. Since the lens is composed of functionally distinct anatomical compartments, with different metabolic activity, biochemical changes in various compartments of the lens were analyzed. Application of NMR-based metabonomics was effective to analyze metabolic changes in the anterior part of the eye after exposure to UV-R. High-resolution (HR) magic angle spinning (MAS) 1H NMR spectroscopy provided high quality spectra from intact tissue of cornea and lens, and provided important information about metabolic alteration occurring in these tissues after exposure to UV-R. The results from this thesis show that in vivo UV-B radiation affects metabolism of the anterior compartments of the eye. Metabolic changes were observed in aqueous humour, cornea, lens and in the different compartments of the lens. The antioxidants, glutathione and ascorbate, several amino acids, high energetic phosphates, and compounds important for membrane building and osmoregulation were substantially altered after exposure to UV-B radiation. Several biochemical effects such as oxidation, membrane disruption, osmoregulatory problems, lipid peroxidation, problems with cellular signalling and impairment of growth and protein synthesis were suggested. After UV-A exposure, no observable metabolic alterations were found in the anterior part of the eye in the present animal models.

The primary goal of this research is to use eye-tracking in the development and usability evaluation of an e-learning tool called "Problem Solving Environment for Continuous Process Design" (PSE). The PSE is meant to aid engineering students in learning the design processes of automated manufacturing systems. PSE is a user-interactive Flash application which gives the user an opportunity to virtually design an automated industrial process by manipulating the parameters associated with it. PSE is evaluated using eye-tracking experiments in which users' eye movements are tracked using camera and sensors to determine users' gaze direction and fixations. The data collected from the experiment is used to determine if use of visual cues improved the usability of the PSE. Results show that use of visual cues for gaze direction improved the usability of the PSE application, based on faster task completion times and improved navigability.

The present study examined whether infants aged 3 to 9 months displayed an adult-like left visual field bias when processing dynamic faces. In Experiment 1 infants aged 6 to 9 months viewed videos of dynamic face stimuli. Eye tracking data revealed that these infants showed a left visual field bias by attending significantly more to the right side of the faces. In Experiment 2 a younger group of infants, aged 3 to 6 months, failed to demonstrate a group left visual field bias. Instead, some infants displayed a consistent left visual field bias whereas others displayed a consistent right visual field bias. To our knowledge, these findings provide the first eye-tracking evidence to suggest the existence of a left visual field bias in infancy.

The present study examined whether infants aged 3 to 9 months displayed an adult-like left visual field bias when processing dynamic faces. In Experiment 1 infants aged 6 to 9 months viewed videos of dynamic face stimuli. Eye tracking data revealed that these infants showed a left visual field bias by attending significantly more to the right side of the faces. In Experiment 2 a younger group of infants, aged 3 to 6 months, failed to demonstrate a group left visual field bias. Instead, some infants displayed a consistent left visual field bias whereas others displayed a consistent right visual field bias. To our knowledge, these findings provide the first eye-tracking evidence to suggest the existence of a left visual field bias in infancy.

The concept of emotion and how to regulate it is a central aspect of modern psychology. Within the process model of emotion regulation (Gross, 1998), one issue is how attentional deployment affects emotion regulation and how this can be measured. In task 1, pictures of positive or negative valence were showed in two conditions, either attend or decrease emotional reaction, while participants’ eye movements were followed with an eye tracker. Ratings of arousal and valence were significantly affected by instruction, but dwell times were only significant for positive pictures. In task 2, participants were directed either to emotional or non-emotional parts of emotional pictures while skin conductance was recorded. Arousal and valence ratings decreased significantly in non-emotional areas, but no effect could be found for skin conductance data. Results were generally weak in regards to the effectiveness of measuring gaze to indicate emotion regulation in the form of attentional deployment. For future studies, research of individual differences in habitual usage of attentional deployment for emotion regulation was suggested.

Introduction Menopause which is defined as a permanent physiological, or natural, cessation of menstrual cycle, plays an important role in the development of ocular surface dryness symptoms and there is an increased prevalence of dry eye in women, especially those aged over 50. Despite the high prevalence of dry eye in post-menopausal women (PMW), very few studies have been undertaken to understand dry eye disease in a group of PMW who are not on Hormone Replacement Therapy (HRT). Studies in the past on PMW have primarily focused on the relationship between HRT and dry eye. Hence, a series of studies were undertaken to understand the clinical aspects of dry eye and their relationship to a variety of tear film components, in a group of PMW with and without symptoms of dry eye. The specific aims of each chapter were as follows: • Chapter 4: To characterize symptoms of dry eye using questionnaires, namely Ocular Surface Disease Index Questionnaire© (OSDI) and the Indiana Dry Eye Questionnaire (DEQ). • Chapter 5: To characterize clinical signs and symptoms in participants who present with and without symptoms of dry eye. • Chapter 6: To compare tear osmolality and ferning patterns in participants with and without dry eye symptoms. • Chapter 7: To investigate the potential relationship between subjective symptoms and clinical signs with tear film lipocalin and lysozyme concentrations in participants with and without dry eye symptoms. • Chapter 8: To optimize a technique for the isolation of total RNA (ribo nucleic acid) and total protein derived from conjunctival epithelial cells collected via conjunctival impression cytology (CIC). • Chapter 9: To quantify the expression of MUC1 (mucin1) and MUC16 (mucin16) mRNA and protein and to investigate the potential relationship between mucin expression and tear film breakup time in a group of participants with and without dry eye symptoms. Methods • Chapter 4: Participants were categorized as being symptomatic or asymptomatic of dry eye based on their response to the OSDI questionnaire. These results were then compared to the DEQ, which has questions related to the frequency of ocular surface symptoms and their diurnal intensity. • Chapter 5: Non invasive tear breakup time (NITBUT) was evaluated using the ALCON Eyemap®. Tear volume was assessed using the Phenol Red Thread (PRT) test and bulbar conjunctival hyperemia was measured using objective (SpectraScan PR650© Spectrophotometer) and subjective (slit lamp) methods. • Chapter 6: Tears were collected via capillary tube. A freezing point depression osmometer was used to measure the osmolality of the tear film. The tear ferning test was performed and evaluated for the quality of ferning, based on the Rolando grading system. • Chapter 7: Tears were collected via capillary tube and an eye wash method. Tear lysozyme and lipocalin concentrations were determined via Western blotting. • Chapter 8: CIC was collected using either Millipore (MP) or Poly Ether Sulfone (PES) membranes. RNA and protein isolation was performed using two different RNA isolation techniques. Two methods of protein isolation from CIC discs were evaluated. RT-PCR of mRNA for MUC1 and western blotting of lipoxygenase type 2 protein (LOX2) was performed to confirm the collection of intact RNA and total protein respectively. • Chapter 9: Tears were collected via capillary tube and an eye wash method. CIC was collected using MP membrane. Expression of MUC1 and MUC16 mRNA was assessed via real time PCR. Expression of both membrane-bound and soluble MUC1 and MUC16 were quantified via Western blotting. Results • Chapter 4: The OSDI total score and sub scores for the Non Dry Eye (NDE) and Dry Eye (DE) groups were significantly different (NDE =7.43 ± 7.71 vs DE = 24.87 ± 13.89; p<0.001). The DEQ scores showed that the DE group exhibited a higher frequency and intensity of symptoms than the NDE group, which worsened as the day progressed (p<0.001). • Chapter 5: The DE group exhibited a significantly shorter NITBUT (5.3 ± 1.7 vs 7.0 ± 2.7 secs; p=0.0012). Tear volume was significantly lower for the DE group (19.3 ± 5.1mm vs. 16.3 ± 5.6mm; p=0.031). Bulbar hyperemia was significantly higher in the DE group for both objective (u’ = 0.285 ± 0.006 vs. 0.282 ± 0.006; p=0.005) and subjective techniques (48.4 ± 10.0 vs 40.6 ± 10.4; p=0.0011). • Chapter 6: Osmolality values in DE individuals were significantly higher than the NDE (328.1 ± 20.8 vs. 315.1 ± 11.3 mOsm/kg; p = 0.02). There was a significant difference between the DE and NDE participants for the ferning patterns (p = 0.019). No significant correlation between tear osmolality and tear ferning was noted (DE: r = 0.12; p > 0.05, NDE: r = -0.17; p > 0.05). • Chapter 7: No difference in tear lysozyme or lipocalin concentration was found between DE and NDE groups, irrespective of tear collection method. Method of collection significantly influenced absolute concentrations (p<0.008). • Chapter 8: There was no significant difference between the two procedures used to isolate RNA and protein from CIC membranes (p>0.05). Total RNA yield was greater with the MP membrane. The mean yield of protein extracted from MP membrane using the two protein isolation techniques also did not show a significant difference. • Chapter 9: No difference was found in the expression of either MUC1 or MUC16 protein or mRNA expression between symptomatic DE and NDE (p>0.05). Weak correlations were found between the NITBUT values compared with either soluble or membrane bound MUC1 and MUC16 expression. Conclusions • Chapter 4: Questionnaires are useful tools to symptomatically divide participants into dry eyed and non dry eyed candidates. However, the questionnaire used to categorise patients can impact on the outcome variables determined. • Chapter 5: Post-menopausal women with dry eye symptoms demonstrate shorter NITBUT, lower tear volume and increased bulbar conjunctival hyperemia than those who have no symptoms. • Chapter 6: Tear osmolality in DE is higher than in NDE. There is a tendency towards less ferning in persons over 50 years of age, regardless of their symptoms. • Chapter 7: Comparison of clinical data with lipocalin and lysozyme concentrations failed to reveal statistically significant correlations. The concentration of either protein was not associated with tear stability or secretion. • Chapter 8: The total RNA yield was greater with the MP membrane. RNeasy Mini (RN) (Qiagen) method is recommended due to enhanced speed as well as on-column isolation and DNase digestion capabilities. CIC with MP membranes followed by immediate freezing and then extraction and processing facilitates the collection of total protein from human conjunctival cells. • Chapter 9: No difference was found in the expression of either MUC1 or MUC16 protein or mRNA expression between symptomatic PMW and asymptomatic controls.

Sjogren’s syndrome (SS) is a systemic autoimmune disease that presents to eye care practitioners with the hallmark symptom of “dry eye.” Stratifying dry eye patients as Sjogren’s positive or negative is a critical differential diagnosis, as SS patients have numerous systemic complications and a forty times greater risk of developing lymphoma. As such, management of this relatively common dry eye sub-population requires specialized care. Since a firm diagnosis requires testing that is both invasive and expensive, patients should be protected from these tests if they are not warranted. In this thesis, studies were therefore undertaken to determine if SS dry eye could be differentiated from other forms of dry eye using two methods: 1) standard clinical tests used in a multi-disciplinary Sjogren’s syndrome clinic and 2) subsequent biological evaluation of collected tear samples and cells from the ocular surface. The former would allow eye care practitioners to conduct appropriate tests and pose suitable questions to ifferentiate these subgroups, and the latter might serve in the future as a relatively non-invasive quantitative means of differentiating such groups through biomarkers.

Introduction: Tear film osmolality is a product of the varying concentrations of dissolved solutes (proteins, lipids and mucins) in the tear fluid. Research suggests that a hyperosmotic tear film is a trait common to all forms of dry eye, and it may be the driving force causing the discomfort, ocular surface damage and inflammation found in both evaporative and tear deficient forms of dry eye disease. Tear film osmolality has been proposed to be the “gold standard” diagnostic test for the evaluation of dry eye disease, as a distinct separation between tear film osmolalities in normal and dry-eyed (aqueous deficient or evaporative) populations has become evident. Historically, tear film osmolality could only be measured in a laboratory setting and required a highly skilled technician to use the instrumentation. The recent development of easy-to-use, small volume osmometers has made it possible for tear film osmolality to be measured clinically. As these instruments are quite new, there has been very little research completed with them. Therefore, a series of studies was conducted to investigate the utility of one of these new osmometers – the Advanced Instruments Model 3100 Nanolitre Osmometer. The specific aims of each chapter were: - Chapter 3: To determine if the Advanced Instruments Model 3100 Nanolitre Osmometer was capable of quantitatively measuring tear film osmolality in a normal population, using 0.5μL tear samples. - Chapter 4: Previous studies have shown the Advanced Instruments Model 3100 Nanolitre Osmometer not significantly different from another commercially available osmometer (Wescor Vapor Pressure Osmometer) for the measurement of human tears. This chapter examined the repeatability of the new instrument over multiple measurements on the same sample and over multiple days. - Chapter 5: To determine if tear film osmolality values varied significantly over the course of a normal working day in a population that was primarily free from symptoms of dry eye. - Chapter 6: To investigate the relationships between tear film osmolality and other commonly used clinical tests for dry eye disease. The clinical tests examined included various questionnaires designed to assess patient symptoms (Single Item Dry Eye Questionnaire (SIDEQ), the Ocular Surface Disease Index (OSDI), and the McMonnies Dry Eye Questionnaire (MMDEQ) and a linear analogue comfort scale (LACS)), a non-invasive tear break-up time test (NIBUT), and examination of ocular surface redness and tear ferning (TF). Secondarily to determine if the other clinical tests demonstrated significant diurnal variations over the course of a normal working day. - Chapter 7: To measure tear film osmolality in a population with mild to moderate symptoms of dry eye disease, and to compare this value with the osmolality of a population of age-matched controls without the disease. Secondarily, to investigate the relationship between tear film osmolality and patient comfort in a population with mild to moderate symptoms of dry eye disease. Methods: - Chapter 3: Tears were collected from 40 volunteer participants with a capillary tube. Some participants were non-contact lens wearers (Non-CL), while others wore either soft or rigid contact lenses (CL). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 4: Tears were collected from 10 volunteer participants using two different collection techniques. Collections were repeated on three separate days (6 study visits total); three osmolality measurements per collection were taken using the Advanced Instruments Model 3100 Nanolitre osmometer. - Chapter 5: Tears were collected from 40 volunteer participants in two separate studies (n=80 in total). Tears were collected with a capillary tube three times a day (morning, mid-day and afternoon), on two separate days (6 study visits total). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 6: Clinical tests were administered and tear samples were collected using a capillary tube from 40 volunteer participants. Measurements were taken three times a day (morning, mid-day and afternoon), on two separate days (6 study visits total). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 7: Participants were classified as either having dry eye disease (DE) or not having dry eye disease (NDE) based on a clinical examination that included a case history, phenol red thread test and biomicroscopy (white light and sodium fluorescein assessment). Tear samples were then collected from all participants using a capillary tube and tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. Participants also completed the SIDEQ, the OSDI, and the MMDEQ. Results: - Chapter 3: The mean tear film osmolality of the population was 298.7±11.4mOsm/Kg. CL wear (soft or rigid) did not appear to have a significant effect on tear film osmolality (CL: 298.5±11.2mOsm/Kg vs. Non-CL: 298.9±11.5mOsm/Kg), although this study was not designed to specifically look at the effects of contact lens wear on tear film osmolality. - Chapter 4: There was reasonably good concordance between measurements of tear film osmolality taken with the Advanced Instruments Model 3100 Nanolitre Osmometer (intraclass correlations range from 0.6497 (F= 0.0582) to 0.9550 (F = 0.5893)). Repeatability appeared to be affected by significant changes in ambient humidity (>10% per day). Concordance was similar with both sampling techniques. - Chapter 5: In the first study, no significant diurnal change in tear film osmolality was found (p>0.05), although a significant difference in measurements taken on Day 1 compared to Day 2 was found (p=0.040). When the first and last 10 participants enrolled were compared, the difference between days was present in the first 10 participants, but not in the last 10; it is likely that the investigator underwent a learning process during the period of the study, and that reflex tearing occurred more often in the early portion of the study compared with the latter portion. In the second study, no significant diurnal change in tear film osmolality was found (p>0.05) and no significant difference in measurements taken on Day 1 compared to Day 2 was found (p>0.05). When tear film osmolality was compared with the number of hours participants were awake, no significant correlation was found (r = 0.07044). - Chapter 6: Significant correlations were not found between tear film osmolality and SIDEQ (r = 0.1347), OSDI (r = 0.0331), MMDEQ (r = 0.2727), LACS (r = -0.1622), NIBUT (r = -0.2280), subjectively graded redness (r=-0.2280), or objectively measured redness (r = 0.1233). A weakly significant correlation was found between TF and tear film osmolality (r = 0.3978). None of the clinical measures (LACS, NIBUT, subjective or objective redness or TF) varied significantly over the course of the day. - Chapter 7: Tear film osmolality was higher in both the right (DE = 311.1±12.4mOsm/Kg, NDE = 306.2±11.2mOsm/Kg) and left eyes (DE = 313.2±11.9mOsm/Kg, NDE = 304.0±7.5mOsm/Kg) of participants, but the difference was only statistically significant in the left eye. Tear film osmolality did not correlate significantly with DE patient symptoms using any of the questionnaires (SIDEQ, OSDI, MMDEQ). Conclusions: - Chapter 3: The Advanced Instruments Model 3100 Nanolitre Osmometer appeared to be capable of measuring tear film osmolality in a normal population. Our population mean was slightly lower than what is reported to be normal (305mOsm/Kg), but it still fell within the range of values reported as normal (297 – 318mOsm/Kg). - Chapter 4: The Advanced Instruments Model 3100 Nanolitre Osmometer demonstrated reasonably good repeatability for the measurement of human tear samples. Unfortunately, the instrumentation appeared to be affected by dramatic weather changes. Maintaining the instrument in a humidity controlled environment may resolve this problem. - Chapter 5: Tear film osmolality did not appear to vary significantly over a normal working day. Inducing reflex tearing, perhaps with an unskilled investigator collecting the tears, can be a significant source of error (as demonstrated in the first study). - Chapter 6: Tear film osmolality did not correlate well with other clinical instruments designed to assess either patient symptoms or signs of dry eye disease in a normal population. Tear film osmolality and tear ferning did demonstrate a weakly significant positive correlation. None of the clinical measures assessed demonstrated a significant diurnal variation over the course of a normal working day. - Chapter 7: Tear film osmolality appeared to be higher in participants with mild to moderate symptoms of dry eye when compared with age matched, asymptomatic controls. Tear film osmolality did not correlate well with patient symptoms in a population of mild to moderate severe dry eyed individuals.

The Rapid Automatized Naming test (RAN) has been shown to be a strong predictor of reading ability (Bowers and Wolf, 1993), however, the nature of this relationship remains unclear. The purpose of this study was to evaluate whether the visual scanning and sequential components of the continuous RAN format are similar to those same visual scanning processes required in reading, and whether these processes partially account for the relationship. The sample consisted of 57 undergraduate students (63.2% female). The majority of the sample was either Caucasian (33.3%) or African American (29.8%). The eye movement measures consisted of three short stories and the continuous versions of two RAN tasks (colors and letters). This study examined the percent of regressions and fixations during both types of tasks (reading text and RAN). The findings suggest that the continuous RAN measures important visual scanning and sequencing processes that are important in predicting reading ability.

Purpose: To test the hypothesis that the fixational stability (FS) of the amblyopic eye (AME) in strabismics will improve when binocular integration is enhanced through ocular alignment and inter-ocular suppression is attenuated by reducing the contrast to the fellow eye (FFE). Methods: 7 strabismic amblyopes (age: 30.8±9.7 yrs) (5 esotropes and 2 exotrope) (VA: AME=0.50±0.30; FFE=-0.12±0.04) showing clinical characteristics of central suppression were recruited. Suppression was then attenuated by a balance point procedure where the contrast to the FFE was reduced in order to maximize binocular integration during a global motion task (GMT) (Baker, 2007). In one case the balance point could not be determined, and the participant was excluded. Ocular alignment was established with a haploscope. Participants dichoptically viewed similar targets [a cross (2.3°) surrounded by a square (11.3°) visual angle] set at 40cm. Target contrasts presented to each eye were either equal (EQ) or attenuated in the FFE (UNEQ) by an amount defined by the GMT. FS was measured over a 5 min period (Viewpoint® Eye Tracker, Arrington Research) and quantified using bivariate contour ellipse areas (BCEA) in four different binocular conditions; unaligned/EQ, unaligned/UNEQ, aligned/EQ and aligned/UNEQ. FS was also measured in 6 control subjects (Age: 25.3±4 yrs; VA: -0.1±0.08). Results: Alignment of the AME was transient and lasting between 30 to 80 seconds. Accordingly, FS was analyzed over the first 30 seconds using repeated measures ANOVA. Post hoc analysis revealed that for the amblyopic subjects, the FS of the AME was significantly improved in aligned/EQ (p=0.015) and aligned/UNEQ (p=0.001). FS of FFE was not different statistically across conditions. BCEA(FFE) & BCEA(AME) were then averaged for each amblyope in the 4 conditions and compared with normals. This averaged BCEA (reduced FS) was significantly greater (p=0.0205) in amblyopes compared to controls except in the case of alignment coupled with reduced suppression (aligned/UNEQ) (p=0.1232). Conclusion: Fixation stability in the amblyopic eye of strabismics appears to improve directly with the degree of binocular integration. The hypothesis is therefore retained.