Optometry

Encryption algorithms provide the securely transmitted data over insecure communication channels. In this paper a different stream cipher scheme is presented which is very simple in hardware implementation and provides relatively high level of security. Geffe generator is used for the generation of a complex key in a unique way. In this modified scheme, keystream is dependent not only on the inputs of the Geffe generator but also on the Gold Codes generated with the help of outputs of pseudo noise (PN) sequences of the two inputs of Geffe generator. Further complexity of the key is increased by introducing automatic shift of the contents of one LFSR to generate a new Gold code.

To develop and validate 28 short Italian sentences for the construction of the Italian version of the Radner Reading Chart to simultaneously measure near visual acuity and reading speed. 41 sentences were constructed in Italian language, following the procedure defined by Radner, to obtain "sentence optotypes" with comparable structure and with the same lexical and grammatical difficulty. Sentences were statistically selected and used in 211 normal, non-presbyopic, native Italian-speaking persons. The most equally matched sentences in terms of reading speed and number of reading errors were selected. To assess the validity of the reading speed results obtained with the 28 selected short sentences, we compared the reading speed and reading errors with the average obtained by reading two long 4th-grade paragraphs (97 and 90 words) under the same conditions. The overall mean reading speed of the tested persons was 189±26wpm. The 28 sentences more similar in terms of reading t...

AIM:

The aim of this study was to evaluate an interdisciplinary visual assessment for multiply challenged children diagnosed with cerebral palsy (CP).
METHOD:

A comprehensive ophthalmological assessment together with a visual classification scale (VCS) and a questionnaire evaluating daily visual function were completed regarding 77 children (41 females, 36 males; age range 3-20y; mean age 8 y 3 mo [SD 4 y 3 mo]; Gross Motor Function Classification System [GMFCS] level V; Manual Ability Classification System level V) who were diagnosed with CP (79.2% spastic quadriplegia, 6.5% athetoid quadriplegia, 10.4% mixed type, 3.9% hemiplegia). All participants had severe to profound motor and intellectual disability and an inability to communicate consistently through either verbal or assisted communication. The interrater and test-retest reliability of the questionnaire and its validity in comparison with the VCS were examined. In addition, the contribution of ophthalmological testing in predicting daily visual function was assessed.
RESULTS:

The ophthalmological examination revealed three diagnostic subgroups: a group with cerebral visual impairment (CVI), a group with optic atrophy, and a group without visual impairment. The questionnaire was found to have high values of interrater reliability (interclass correlation coefficient [ICC]=0.873; 95% confidence interval [CI] 0.762-0.935) and test-retest reliability (ICC=0.988; 95% CI 0.964-0.996). Validity was established for the questionnaire factors: task-orientated visual function (r=0.802; 95% CI 0.669-0.885) and basic visual skills (r=0.691; 95% CI 0.504-0.816). The questionnaire provided information about daily visual performance not available from one-time ophthalmological testing, particularly for participants diagnosed with CVI. The visual performance scale significantly predicted daily visual function for all groups.
INTERPRETATION:

This study highlights the benefits of implementing a diagnostic performance scale as well as a reliable functional questionnaire to achieve a precise visual assessment of children with severe neurological impairment.

Background: Job satisfaction describes an employee's motivation and/or feeling of satisfaction towards his/her work. Globally, healthcare professionals' turnover and retention play a critical role in the delivery of essential health services. In Ghana, however, little has been done to ascertain job satisfaction levels among human resources for eye-health. The objective of this study therefore was to assess job satisfaction and its associated factors among optom-etrists in Ghana. Methods: A cross-sectional survey was conducted among 304 registered and licensed optometrists of the Ghana Optometric Association between September 2018 and June 2019. A validated, well-structured questionnaire was used to elicit information on socio-demographic characteristics of participants and measures on job satisfaction. Scores from a five-point Likert scale was employed to examine job satisfaction and its associated factors. Linear regression analyses were used to evaluate the association between overall job satisfaction and its associated factors using Rasch logit scores. Results: A total of 214 optometrists gave valid responses to the questionnaires used for the final analysis. The mean (± SD) score of the overall perception of job satisfaction among optometrists was 3.36 (± 1.00), with 74.3% of them being satisfied with their jobs. After statistical adjustment, Good work-life balance (Unstandardized coefficient (β) = 0.288, p = 0.001), Salary (β = 0.222, p < 0.0005), Supervision (β = 0.117, p = 0.044), and Continuing Education Opportunities (β = 0.138, p = 0.017) were all significantly associated with higher levels of overall job satisfaction. Conclusions: Most optometrists were satisfied with their jobs. Effective strategic planning and management of human resources for eye-health in Ghana are essential in the development of quality eye-health systems and the provision of high-quality eyecare services.