ColourSpot, a novel gamified tablet-based test for accurate diagnosis of color vision deficiency in young children

There is a need for a straightforward, accessible and accurate pediatric test for color vision deficiency (CVD). We present and evaluate ColourSpot, a self-administered, gamified and color calibrated tablet-based app, which diagnoses CVD from age 4. Children tap colored targets with saturations that are altered adaptively along the three dichromatic confusion lines. Two cohorts (Total, N = 772; Discovery, N = 236; Validation, N = 536) of 4–7-year-old boys were screened using the Ishihara test for Unlettered Persons and the Neitz Test of Color Vision. ColourSpot was evaluated by testing any child who made an error on the Ishihara Unlettered test alongside a randomly selected control group who made no errors. Psychometric functions were fit to the data and “threshold ratios” were calculated as the ratio of tritan to protan or deutan thresholds. Based on the threshold ratios derived using an optimal fitting procedure that best categorized children in the discovery cohort, ColourSpot showed a sensitivity of 1.00 and a specificity of 0.97 for classifying CVD against the Ishihara Unlettered in the independent validation cohort. ColourSpot was also able to categorize individuals with ambiguous results on the Ishihara Unlettered. Compared to the Ishihara Unlettered, the Neitz Test generated an unacceptably high level of false positives. ColourSpot is an accurate test for CVD, which could be used by anyone to diagnose CVD in children from the start of their education. ColourSpot could also have a wider impact: its interface could be adapted for measuring other aspects of children’s visual performance.

Progressive multifocal leukoencephalopathy in a patient with occult hypogammaglobulinemia experiencing bilateral visual impairment

Introduction: Progressive multifocal leukoencephalopathy (PML) is a rare, lethal, demyelinating disease classically seen in profoundly immunosuppressed individuals. It is caused by intracerebral infection by John Cunningham polyomavirus (JCV). We report a rare case of PML in a man with presumed immunocompetence at presentation experiencing bilateral painless visual impairment. Case Description: A 60-year-old man with a 3-week history of bilateral painless visual impairment attended our ophthalmology department. Unusually, he navigated around the room well and was able to read 4 of 13 Ishihara test plates in spite of a best-corrected visual acuity of counting fingers at 1 m bilaterally. Slit lamp examination, routine blood tests and optical coherence tomography (OCT) of the maculae and discs were unremarkable. Diffuse hyperintense white matter lesions on T2-weighted magnetic resonance imaging of the brain and detection of JCV within the parietal lobe tissue obtained by biopsy confirmed PML. Additional investigations identified an underlying hypogammaglobulinaemia, which may have initiated PML. He received intravenous immunoglobulin but passed away 2 months after diagnosis. Conclusions: To our knowledge this case is one of only a handful worldwide to describe PML developing in a patient with presumed immunocompetence at presentation – there was no previous history of recurrent, chronic, or atypical infections. There has only been one other report of visual symptoms presenting as the primary complaint. The case illustrates the importance of ruling out organic, central nervous system pathology in patients presenting with visual loss and normal objective visual function tests such as slit lamp examination and OCT.

Prevalence of Color Vision Deficiency among Dental Practitioners and its Effect on Shade Matching Ability

Objective: Shade selection is a crucial step in achieving aesthetically-pleasing restorations, and it is affected by the dentist’s ability to match the shade of the patient’s teeth. Color Deficiency Disease (CVD) has been thought to be a potential factor affecting color perception. The study aims to find the prevalence of CVD between dentists and dental students and to evaluate its effect on shade matching ability. Methods: A sample of 319 dentists and dental students in the College of Dentistry at Ajman University, Ajman, UAE was examined with the Ishihara test to find the prevalence of CVD. Then participants with CVD were tested for shade matching ability, and were compared to participants with normal color vision with the same gender and qualification level. They were asked to match 10 random composite samples with different shades to a custom shade guide made from the same composite material. A score was calculated, representing the number of correct answers they achieved. Results: The results showed that 8 out of 143 males (5.6%) had CVD, and 0 out of 176 females had CVD. There was no significant difference in the score of shade matching test between participants with CVD and participants with normal color vision (p=0.075). Conclusion: Males showed a higher prevalence of color vision deficiency than females. CVD had no significant effect on shade matching ability.

Spectral Color Management in Virtual Reality Scenes

Virtual reality has reached a great maturity in recent years. However, the quality of its visual appearance still leaves room for improvement. One of the most difficult features to represent in real-time 3D rendered virtual scenes is color fidelity, since there are many factors influencing the faithful reproduction of color. In this paper we introduce a method for improving color fidelity in virtual reality systems based in real-time 3D rendering systems. We developed a color management system for 3D rendered scenes divided into two levels. At the first level, color management is applied only to light sources defined inside the virtual scene. At the second level, we applied spectral techniques over the hyperspectral textures of 3D objects to obtain a higher degree of color fidelity. To illustrate the application of this color management method, we simulated a virtual version of the Ishihara test for color blindness deficiency detection.

Neuropati Optik Kompresif Bilateral yang Terinduksi oleh Schwannoma

The aim of this case report was to present further study about diagnosis and management of bilateral compressive optic neuropathy induced by schwannoma. This case report will discuss about the definition, classification, etiology, clinical diagnosis and treatment for compressive optic neuropathy. A case report. 43 years-old woman complained about blurred vision since 2 years ago. She also complained about pain on her right head while she was walking. There was no history of tinnitus or hearing loss. She had a history of contraception pill uses and progesterone injection every 3 months for 5 years alternately. She also suffered from schwannoma in cerebello pontine angle based on MRI and histopathology examination. From physical examination, best corrected visual acuity on right eye was 5/6 PHNI and on left eye was 5/8 PHNI. Ishihara test showed decreased colour vision. There was also ataxic gait. From anterior segment examination, there were decreased light reflex and RAPD. From posterior segment examination, there were papilloedema and elevation on both eyes proved by OCT and fundal imaging. Neuroprotector therapy and surgery show a good result. Ishihara test are improving, light reflex are increasing and there are no RAPD anymore. From posterior segment, papilloedema are slowly diminished. The patient presents a case of bilateral compressive optic neuropathy induced by schwannoma. Neuroprotector and surgery show a good result.

Visual Outcome after Oral versus Intravenous Methylpredisolone Therapy for Bilateral Optic Neuritis in Adults

Introduction: Bilateral optic neuritis in adults is rarer then unilateral optic neuritis. The purpose of this study was to know the clinical profile and to know the visual outcome of bilateral optic neuritis in adult patients after oral versus intravenous methylprednisolone therapy.Methods: A retrospective review of patients with bilateral optic neuritis referred to dr.Sardjito General Hospital, Yogyakarta from 2011-2014. The data consisted of bilateral optic neuritis, unassociated with other pathologic processes. There are two groups of patients: Group A taking oral methylprednisolone 1mg/kgBB and Group B received intravenous methylprednisolone (as ONTT guideline). Visual acuity, visual field with Goldmann Perimetry, RAPD (Relative Afferent Puppilary Defect), Ishihara test and direct ophthalmoscopy evaluation were recorded and analysed in both group at baseline, 1 week, 1 month and 3 months follow up. Results: Nineteen women and 9 men, with age range of 18-54 years old, had bilateral optic neuritis. The majority of the patients suffered from retrobulbar neuritis (43%), papilitis (39%) and neuroretinitis (18%). The average visual acuity before treatment in Group A was 0.22 ± 0.29 and in Group B had poorer average visual acuity 0.03±0.04 (p>0.05). But the trend of visual recovery in Group B with visual acuity at baseline worsen, the recovery of visual acuity was faster and better at one week. After one month the visual acuity was comparable in both groups (p>0.05).Conclusions: Visual improvement in early period of adult bilateral optic neuritis was similar after oral and intravenous methylprednisolone therapy.Keywords: Bilateral optic neuritis, methylprednisolone therapy, visual outcome

Real-Time Recoloring Ishihara Plates Using Artificial Neural Networks for Helping Colorblind People

Vision sense is achieved using cells called rods (luminosity) and cones (color). Color perception is required when interacting with educational materials, industrial environments, traffic signals, among others, but colorblind people have difficulties perceiving colors. There are different tests for colorblindness like Ishihara plates test, which have numbers with colors that are confused with colorblindness. Advances in computer sciences produced digital assistants for colorblindness, but there are possibilities to improve them using artificial intelligence because its techniques have exhibited great results when classifying parameters. This chapter proposes the use of artificial neural networks, an artificial intelligence technique, for learning the colors that colorblind people cannot distinguish well by using as input data the Ishihara plates and recoloring the image by increasing its brightness. Results are tested with a real colorblind people who successfully pass the Ishihara test.