In a prospective population-based study in Stockholm County, 1998-2000, the incidence of retinopathy of prematurity (ROP) was investigated and was found to be 36% in prematurely-born infants with a birth weight of ≤ 1500 grams. Compared to a study performed ten years ago, the overall incidence was unchanged, but was reduced in “mature” infants and increased in immature ones. The incidence of ROP was 25% in infants with a gestational age of ≤ 32 weeks at birth. The main risk factors for ROP were the gestational age at birth, followed by the birth weight. Current guidelines for ROP screening in Sweden were modified. A 10-year follow-up study of the ophthalmological findings in prematurely-born children, previously included in a prospective population-based incidence study of ROP, was performed. The children were compared with full-term ones. Prematurely-born children ran a four times higher risk of refractive errors than full-term ones. The cryotreated children had the highest risk, but those without ROP also had more refractive errors than the full-terms. Within the group of prematurely-born children, the cryotreated ones had the highest prevalence of myopia, astigmatism and anisometropia, but no difference was found regarding hypermetropia. The visual acuity of prematurely-born children was poorer than that of the full-terms. The cryotreated children and those with neurological complications had the most marked reduction, but the children without ROP and neurological findings also had a poorer visual outcome than the full-terms. The prevalence of visual impairment was 1.8% among the prematurely-born children, and was due to ROP in half the cases and cerebral lesions in the others. The cryotreated children had constricted peripheral visual fields compared to the untreated prematurely-born and full-term children. The central visual fields tended to be reduced in the prematurely-born children compared to the full-terms, but no difference was observed within the preterm group.

O objetivo do estudo foi medir a acuidade visual (AV) em crianças com diagnóstico de hidrocefalia, apresentando ou não a válvula de derivação ventricular (DVP). Participaram da pesquisa um total de 55 crianças (34 F e 21M) com diagnóstico de hidrocefalia (45 com DVP e 10 sem DVP), com idade entre zero a 291 semanas (média 74 semanas). A AV foi medida pela técnica do Potencial Visual Evocado de Varredura e os resultados foram comparados a valores de referência (Norcia, 1985b). Os diagnósticos etiológicos que levaram à hidrocefalia foram: hemorragia intracraniana (25 crianças), mielomeningocele (20 crianças) e hidrocefalia congênita (10 crianças). O diagnóstico de hidrocefalia foi estabelecido em média no 16° dia de vida. Verificamos que, 31 crianças tiveram o procedimento realizado com menos de 15 dias do diagnóstico de hidrocefalia enquanto que em 14 a válvula foi instalada após 15 dias. Das 55 crianças avaliadas no 1° exame, 18 fizeram o 2° exame, 13 fizeram o 3° exame, 10 completaram quatro exames e apenas cinco completaram as cinco avaliações. Os resultados mostram que dentre as 101 avaliações de AV realizadas em todas as crianças, 95 exames (94%) se mostraram alterados e seis normais. Não há diferença estatística entre a AV das crianças sem derivação em comparação com aquelas crianças cuja DVP foi realizada com tempo de derivação maior que 15 dias (p = 0.699). Houve, todavia, uma diferença estatística na AV, quando comparamos as crianças, cujas derivações foram realizadas em até 15 dias do diagnóstico da hidrocefalia, com aquelas cuja derivação foi realizada após 15 dias (p = 0.038) ou com aquelas que não foram derivadas (p = 0.031). Crianças que não tiveram complicações na DVP tiveram um melhor resultado de AV quando comparado com o grupo com complicação (p = 0.0001). No grupo de crianças com complicação, novamente aquelas que foram derivadas com tempo inferior a 15 dias do diagnóstico da hidrocefalia apresentou melhores resultados de AV quando comparado com aquelas crianças com complicação cuja derivação foi realizada com mais de 15 dias (p = 0.029). Nós concluímos que é possível a medida da acuidade visual de resolução pelos PVEs de varredura em crianças com diagnóstico de hidrocefalia e os valores geralmente são piores comparando aos valores normativos. O tempo da derivação e o número de complicações decorrentes da DVP parecem interferir nesta diferença. Em nosso conhecimento, este foi o primeiro trabalho a avaliar progressivamente, a acuidade visual de crianças, nos primeiros anos de vida, com hidrocefalia, com ou sem DVP e correlacionar o resultado com o tempo de derivações e número de complicações. Apesar da grande evolução tecnológica alcançada pela oftalmologia, ainda não somos capazes de prevenir as alterações visuais detectáveis pelo simples exame de AV nas crianças com hidrocefalia. O tempo para a inserção da válvula de derivação e o tratamento para as complicações ainda são medidas retardadas devido à prematuridade, instabilidade hemodinâmica e a não autorização do familiar. Estes motivos podem comprometer o desenvolvimento visual destas crianças. / The objective was to measure the visual acuity (VA) of children with the diagnosis of hydrocephalus with or without peritoneal-ventricular shunt (PVS). A total of 55 children with the diagnosis of hydrocephalus (45 with PVS and 10 without PVS) were included in the study (34F and 21M), with an age range of 0 to 291 weeks (mean=74 weeks). The VA was measured by the sweep visual evoked potential technique and the results were compared with reference values proposed by Norcia (1985b). Etiological diagnosis of the hydrocephalus was as follows: intracranial hemorrhage (25 children), meningomyelocele (20 children) and congenital hydrocephalus (10 children). The diagnosis of hydrocephalus was made in an average time of 16 days of life. After the diagnosis, the insertion of the PVS, when made, was accomplished in average on the 16th day. Of those with a PVS, in 31 the ventricular valve was inserted before 15 days after the diagnosis whereas in 14 in shunt was inserted after 15 days. Of the 55 children evaluated in the first exam, 18 were evaluated in a second exam, 13 did the third exam, 10 completed 4 exams and only 5 completed the 5 evaluations. The results of the 101 sweep visual evoked potential performed in all children, 95 exams (94%) were abnormal and only 6 were normal. There was no statistical difference in the VA of children without a ventricular shunt in comparison with those in which the shunt was inserted after 15 days of the diagnosis of hydrocephalus (p=0.699). There was, however, a statistical difference in the VA between children with a ventricular shunt inserted before 15 days of the diagnosis and children with a ventricular shunt after 15 days (p=0.038) or those without a shunt (p=0.031). Children with no complications of the ventricular shunt had a better VA as compared to those with shunt complications (p= 0.0001). In the group of children with complications, again those who had a shunt inserted before 15 days bad better VA results in comparison to those in whom the shunt was inserted after 15days (p=0.029). We concluded that measuring visual acuity by sweep visual evoked potential is feasible in children with the diagnosis of hydrocephalus and that results are usually worse comparing with reference values. The timing for insertion of a ventricular shunt and the occurrence of complications of this procedure are factors that may influence the VA. To our knowledge, this is the first study that progressively evaluated the VA in children, of early age, with hydrocephalus, with or without a ventricular shunt and correlated the VA with the timing and complications of the ventricular shunt. Despite the great technological advance in ophthalmology, we are still unable to prevent visual impairments, detectable by simple visual acuity tests, in children with hydrocephalus. The timing of the insertion of the ventricular shunt and the adequate treatment of the potential complications may be delayed due to prematurity, hemodynamic instability and family refusal. This delay may compromise the visual development of these children.

Medimos a acuidade visual em crianças com paralisia cerebral do tipo espástica, classificadas em tetraplégicas, diplégicas e hemiplégicas, de acordo com o seu prejuízo motor, pelo método dos potenciais visuais evocados de varredura. Encontramos uma redução na acuidade visual em todos as crianças com tetraplegia e diplegia e em 94% das crianças com hemiplegia. Ambliopia foi identificada em 16% das crianças. Uma alta correlacão entre o prejuízo motor e a redução da acuidade visual foi encontrada para todas as classes. Concluímos que a acuidade visual está reduzida na paralisia cerebral espástica e que esta é de origem cortical, uma vez que o exame oftalmológico de todas as crianças era normal. / We measured the visual acuity in children with spastic cerebral palsy classified as tetraplegic, diplegic and hemiplegic according to their motor impairment by the sweep visual evoked potential method. We found a reduction in the visual acuity of all tetraplegic and diplegic and in 94% of the hemiplegic children. Ambliopia was found in 16% of children. A high correlation was found between the motor impairment and the reduction in the visual acuity. We conclude that the visual acuity was reducted in the spastic cerebral palsy and the origins are presumed to be cortical since the ophthalmological exam in all children was normal.

INTRODUÇÃO: A degeneração macular relacionada à idade (DMRI) é a principal causa de perda de visão irreversível e cegueira mundialmente. A perda da visão central interfere nas atividades de vida diária, como o reconhecimento facial, leitura e escrita, direção de veículos automotores e em atividades funcionais e de lazer. Esta perda de visão relaciona-se também com o desencadeamento de quadros de ansiedade e depressão. Este estudo avaliou a qualidade de vida visual em pacientes com degeneração macular relacionada à idade neovascular por meio do questionário de função visual 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25). MÉTODOS: Estudo clínico observacional de 87 pacientes de ambos os sexos, com idade >= 50 anos e com o diagnóstico de DMRI neovascular unilateral ou bilateral. Todos os pacientes responderam ao questionário de função visual NEI VFQ- 25 no final do tratamento em regime Tratar e Estender ou PrONTO, com as drogas antiangiogênicas ranibizumabe ou aflibercepte. RESULTADOS: A idade dos pacientes foi a variável que menos influenciou a qualidade de vida visual dos pacientes. O gênero teve uma influência um pouco maior que a idade, no entanto, a lateralidade da doença demonstrou maior influência na qualidade de vida visual, comparada ao gênero e idade dos pacientes e foi significante para oito dos 12 domínios do questionário de função visual NEI VFQ-25. Os pacientes com acometimento bilateral tiveram pontuações mais baixas que os com doença unilateral em todos os domínios do questionário. A acuidade visual corrigida (AVc) foi a variável que apresentou o maior número de domínios com valores significantes e, portanto, foi a variável que mais se correlacionou com a qualidade de vida visual. A AVc do melhor olho (MO) foi significante para a maioria dos domínios relacionados com a visão, ao contrário do pior olho (PO) que não foi significante para nenhum domínio do questionário. CONCLUSÃO: Todas as variáveis testadas afetaram a qualidade de vida visual dos pacientes, onde a lateralidade teve uma maior influência, seguida pela idade e sexo dos pacientes. Na tomada de decisão para o tratamento de pacientes com DMRI neovascular, pelo menos para esta população, a manutenção da AVc do MO >= 0,5 (escala decimal de Snellen) foi essencial para a manutenção de boa qualidade de vida visual, independente da AVc do PO, que não teve efeito significante em nenhum domínio do questionário de função visual NEI VFQ-25 / INTRODUCTION: The neovascular age-related macular degeneration (AMD) is the main cause of irreversible loss of vision and blindness woldwide. The loss of the central visual field interferes on daily activities such as facial recognition, reading and writing, driving as well as functional and leasure activities. This loss of vision may also increases anxiety and depression for this age group. To evaluate the impact of neovascular AMD on the visual quality of life of patients using the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25). METHODS: This was an observational clinical, with 87 patients of both genders, with age >= 50 years and a clinical diagnosis of unilateral or bilateral neovascular age related macular degeneration. All patients answered the visual functioning questionaire NEI VFQ-25 at the end of the treatment with the Treat and Extend or PrONTO regimen using antiangiogenic drugs ranibizumab or aflibercept. RESULTS: The age of patients was the variable with the lower influence on the quality of life of the patients. Gender had an influence slightly higher then the age, however, the laterality of the disease had the highest influence on the quality of life, compared with age and gender, and was significant for 8 of the 12 domains of the visual functioning questionaire NEI VFQ-25. The patients with bilateral age-related macular degeneration had lower scores than patients with unilateral disease for all domains of the questionaire. Visual acuity was the variable with the higher number of domains with significant values, and therefore the variable with the higher correlation with the quality of life. The visual acuity of the best eye (BE) was significant for most of the vision related domains, in opposition the the visual acuity of the worst eye (WE) which was not significant for any domain of the questionaire. CONCLUSION: All variables tested affected the visual quality of life, where the laterality of the disease had the highest influence, followed by the age and gender of the patients. The decision process for the treatment of patients with neovascular AMD, at least for this population, keeping the visual acuity of the BE >= 0,5 (Snellen\'s decimal scale) was essential to maintain a long term quality of life, despite the visual acuity of the worst eye, that had no significant effect on any domain of the visual functioning quaestionaire NEI VFQ-25

Introduction A full-thickness macular hole (FTMH) is a round deformity in the fovea that involve alllayers of the neurosensory retina. The condition is usually symptomatic and is associatedwith a decreased visual acuity (VA). Large FTMHs are associated to a larger decrease in VA.To treat FTMH pars plana vitrectomy (PPV) is performed to repair the hole. There aredifferent dimensions of instruments in PPV but limited information on the outcome usingeach dimension. Aim This study aims to assess the healing rate of large FTMHs after 25-gauge vitrectomy. Methods The study is a retrospective record review. Patients were identified through the surgicalintervention registry at the Department of Ophthalmology, USÖ. The study included largeFTMHs (diameter > 400 μm) who underwent 25-gauge PPV at USÖ between 2015-2017. Results After 25-gauge PPV 19 (82.6%) out of 23 included eyes healed. No significant difference inhealing rate between subgroups of different sized FTMHs was discovered. Out of 4 eyes thatfailed to heal, 1 patient underwent a reoperation and the other 3 either chose not to or it wasdeemed not indicated. A statistically significant increase in mean VA postoperatively wasobserved. The most reported complications postoperatively were gas cataract and atemporary increase in intraocular pressure. In 7 cases the PPV led to an accelerateddevelopment of cataract and cataract surgery. Conclusion The majority of FTMHs healed after 25-gauge PPV and the mean VA increased after surgery.The most common complications were secondary cataract and temporary increase in IOP.

Autonomous vehicles is going to be a part of future transport of goods and people, but to make them usable in unpredictable situations presented in real traffic, there is need for backup systems for manual vehicle control. Teleoperation, where a driver controls the vehicle remotely, has been proposed as a backup system for this purpose. This technique is highly dependent on stable and large wireless network bandwidth to transmit high resolution video from the vehicle to the driver station. Reduction in network bandwidth, resulting in a reduced level of detail in the video stream, could lead to a higher risk of driver error. This thesis is a two part investigation. One part looking into whether lower resolution and increased lossy compression of video at the operator station affects driver performance and safety of operation during teleoperation. The second part covers implementation of two vision-based driver assistance systems, one which detects and highlights vehicles and pedestrians in front of the vehicle, and one which detects and highlights lane markings. A driving test was performed at an asphalt track with white markings for track boundaries, with different levels of video quality presented to the driver. Reducing video quality did have a negative effect on lap time and increased the number of times the track boundary was crossed. The test was performed with a small group of drivers, so the results can only be interpreted as an indication toward that video quality can negatively affect driver performance. The vision-based driver assistance systems for detection and marking of pedestrians was tested by showing a test group pre-recorded video shot in traffic, and them reacting when they saw a pedestrian about to cross the road. The results of a one-way analysis of variance, shows that video quality significantly affect reaction times, with p = 0.02181 at significance level α = 0.05. A two-way analysis of variance was also conducted, accounting for video quality, the use of a driver assistance system marking pedestrians, and the interaction between these two. The results point to that marking pedestrians in very low quality video does help reduce reaction times, but the results are not significant at significance level α = 0.05.

The vestibular system senses head motion and facilitates gaze stabilization, allowing for clear vision during movement. The vestibulo-ocular reflex (VOR) causes the eyes to move opposite head motion, thus maintaining focus on a target. Consequently, uncompensated loss of vestibular function leads to reduced VOR function resulting in dizziness, nausea, and visual disturbance. Different testing methods have been developed to measure VOR loss. These tests generally require bulky, expensive equipment, and must be performed by a trained examiner. A newly developed digital form of the dynamic visual acuity (DVA) test requires less equipment, is cost-effective, and may be performed at home making it more accessible. The purpose of this study was to determine the validity and test-retest reliability of the digital DVA test and provide normative data for healthy adults. Fifteen adults – 10 female and 5 male (mean age = 22.0 ± 3.1, range: 19-31 years) – completed the study. Exclusion criteria included age older than 49 years, history of vestibular or neurological disorders, and history of significant head injury. Subjects were screened for normal vestibular function using video head impulse testing. The study consisted of two visits, 3-15 days apart. Participants underwent DVA testing with both the validated NeuroCom (InVision software) system and newly developed digital DVA during the initial visit and the digital DVA during the second visit. The digital DVA system consists of a laptop computer paired with a head/eye tracker (Tobii Eye Tracker 5) and Health in Motion software (Blue Marble Health Company). Outcome measures of interest were the difference between static and dynamic visual acuity measured in LogMAR (DVA loss) for rightward and leftward head movement. Pearson Product-Moment bivariate correlations were used to determine validity of the digital DVA outcomes compared to NeuroCom outcomes. Intraclass correlation coefficients (ICCs) were calculated to determine test-retest reliability of the digital DVA. Pearson correlation coefficients for validity were r = 0.025 and r = -0.015 for left and right DVA loss, respectively. ICCs for test-retest reliability were r = 0.366 and r = 0.313 for left and right DVA loss, respectively. Mean values across both sessions for left and right DVA loss measured by digital DVA were 0.26 ± 0.13 and 0.26 ± 0.11, respectively. Correlations between the digital DVA and standard computerized DVA were poor indicating the need for further development of the current digital system/software. Test-retest reliability for the digital DVA system in its current state was also poor. Tobii sensor used in the software is limited by a 200 ms delay in reporting head motion to the software. Future development of a digital DVA may need to consider other sensors. The current digital DVA will not replace the computerized system; however, it may provide important information for clinicians who do not have access to computerized DVA.

Purpose: To determine whether symptoms of dizziness and fall rates change due to routine cataract surgery and to determine the influence of visual and refractive factors on these common problems in older adults. Methods: Self-reported dizziness and falls were determined in 287 subjects (mean age of 76.5±6.3 years, 55% females) before and after routine cataract surgery for the first (81, 28%), second (109, 38%) and both eyes (97, 34%). Six-month falls rates were determined using self-reported retrospective data. Dizziness was determined using the short-form of the Dizziness Handicap Inventory. Results: The number of patients with dizziness reduced significantly after cataract surgery (52% vs. 38%; χ2 = 19.14 , p<0.001), but the reduction in number of patients who fell in the 6-months post surgery was not significant (23% vs. 20%; χ2= 0.87, p=0.35). Multivariate logistic regression analyses found significant links between post-operative falls and change in spectacle type (increased risk if switched into multifocal spectacles). Post-operative dizziness was associated with changes in best eye visual acuity and changes in oblique astigmatic correction. Conclusions: Dizziness is significantly reduced by cataract surgery and this is linked with improvements in best eye visual acuity, although changes in oblique astigmatic correction increased dizziness. The lack of improvement in falls rate may be associated with switching into multifocal spectacle wear after surgery. / The Dunhill Medical Trust

Dizziness is a common, multifactorial problem that causes reductions in quality of life and is a major risk factor for falls, but the role of vision is a very under-researched area. This study aimed to investigate any link between dizziness and vision and to establish if changes in spectacle lens correction could elicit dizziness symptoms. A link between dizziness and self-reported poor vision was indicated in the epidemiological literature as shown by a systematic review, provided lightheadedness was not included in the definition of dizziness. Cases of individuals who reported vision-related dizziness were investigated to determine potential areas of research for this thesis and subsequently two studies investigated the effects of refractive correction changes on dizziness status. The first study was limited by logistical problems, although it highlighted limitations in the short form of the Dizziness Handicap Inventory that was used to quantify dizziness. Results of an optometry practice recheck study found that oblique cylindrical changes were significantly more likely to be associated with dizziness symptoms than other spectacle lens changes. It also highlighted that optometrists do not ask/record about dizziness symptoms with only 4% of records including “dizziness” as a problem when 38% of patients reported dizziness symptoms when directly asked. All studies highlighted a need for a patient-reported outcome measure to be designed to assess vision-related dizziness. Literature review, interviews with experts and patients and focus groups led to the development of a pilot questionnaire and subsequently a 25-item Vision-Related Dizziness instrument, the VRD-25. This was validated using responses from 223 respondents, with 79 participants completing the questionnaire a second time to provide test-retest data. Two subscales of VRD-12-frequency (VRD-12f) and VRD-13-severity (VRD-13s) were shown to be unidimensional and had good psychometric properties, convergent validity and test-retest repeatability. The VRD-25 is the only patient-reported outcome measure developed to date to assess vision related dizziness and will hopefully provide the platform to further grow this under-researched area that seems likely to provide important clinical information. / College of Optometrists sponsored the research with a Postgraduate Research Scholarship

PURPOSE: Gait during obstacle negotiation is adapted in visually normal subjects whose vision is temporarily and unilaterally blurred or occluded. This study was conducted to examine whether gait parameters in individuals with long-standing deficient stereopsis are similarly adapted. METHODS: Twelve visually normal subjects and 16 individuals with deficient stereopsis due to amblyopia and/or its associated conditions negotiated floor-based obstacles of different heights (7-22 cm). Trials were conducted during binocular viewing and monocular occlusion. Analyses focused on foot placement before the obstacle and toe clearance over it. RESULTS: Across all viewing conditions, there were significant group-by-obstacle height interactions for toe clearance (P < 0.001), walking velocity (P = 0.003), and penultimate step length (P = 0.022). Toe clearance decreased (approximately 0.7 cm) with increasing obstacle height in visually normal subjects, but it increased (approximately 1.5 cm) with increasing obstacle height in the stereo-deficient group. Walking velocity and penultimate step length decreased with increasing obstacle height in both groups, but the reduction was more pronounced in stereo-deficient individuals. Post hoc analyses indicated group differences in toe clearance and penultimate step length when negotiating the highest obstacle (P < 0.05). CONCLUSIONS: Occlusion of either eye caused significant and similar gait changes in both groups, suggesting that in stereo-deficient individuals, as in visually normal subjects, both eyes contribute usefully to the execution of adaptive gait. Under monocular and binocular viewing, obstacle-crossing performance in stereo-deficient individuals was more cautious when compared with that of visually normal subjects, but this difference became evident only when the subjects were negotiating higher obstacles; suggesting that such individuals may be at greater risk of tripping or falling during everyday locomotion.