The effect of filters and varying illumination on contrast sensitivity in eyes with moderate to severe visual impairment.

PURPOSE: To investigate the effect of filters and illumination on contrast sensitivity in persons with cataract, pseudophakia, maculopathy and glaucoma to provide a guide for eye care providers in low vision rehabilitation. MATERIALS AND METHODS: A within-subjects experimental design with a counter-balanced presentation technique was employed in this study. The contrast sensitivity of eyes with cataract, pseudophakia, maculopathy and glaucoma was measured with filters (no filter, yellow, pink and orange) combined with increasing illumination levels (100 lx, 300 lx, 700 lx and 1000 lx) using the SpotChecks™ contrast sensitivity chart. The data were analyzed using descriptive statistics and two-way repeated measures ANOVA. RESULTS: The yellow filter at 100 lx significantly improved contrast sensitivity in the maculopathy group. There were no significant improvements with either intervention in the rest of the groups. There was, however, a significant interaction between filters and illumination in the cataract group. CONCLUSION: There were small improvements in contrast sensitivity at low illumination levels with the yellow filter in the maculopathy group, and this could be considered in clinical practice and low vision rehabilitation. Overall, filters at most illumination levels did not benefit most groups.

Disability glare and nighttime driving performance among commercial drivers in Ghana.

OBJECTIVE: Glare caused by the headlights of on-coming vehicles risk safe driving at night. The study aimed to determine the relationship between glare exposure and nighttime driving performance among commercial drivers in Ghana. METHODS: This cross-sectional study involved commercial drivers with complaints of nighttime driving difficulties (N = 80; mean age = 41.5 ± 11.1 years). A questionnaire was used to investigate nighttime driving performance following glare exposure. We measured contrast sensitivity and visual acuity under photopic conditions. With an experimental setup in a mesopic setting, we measured visual acuity with and without glare exposure. The difference between the two mesopic visual acuities was quantified as disability glare index. With the same setup, photostress recovery time was also measured. Regression analyses were used to determine the relationship between nighttime driving performance score and the measures taken in both photopic and mesopic settings. RESULTS: The average nighttime driving performance score was 47.8 ± 17.5. Driving performance was negatively correlated with all variables (R = -0.87 to -0.30, all p < .01), except contrast sensitivity (R = 0.74, p < .01). A multiple linear regression showed that the model with all variables explained 83.8% of the variance, but only disability glare index was a significant predictor of nighttime driving performance following glare exposure (standardized B = -0.61, p < .01). CONCLUSION: Our results show that the change in mesopic visual acuities following glare can predict nighttime driving performance. This measure can be incorporated into the assessment of driving fitness by licensing departments to evaluate whether a person can drive safely at night amidst glare exposure.

Knowledge, Attitudes and Practices of Postnatal Mothers on Ophthalmia Neonatorum in the Central Region, Ghana.

Health education is key in the prevention of Ophthalmia Neonatorum (ON). However, health education in relation to eye care in Ghana is very low. To determine the knowledge, attitudes and practices (KAPs) of mothers on Ophthalmia Neonatorum (eye infection in newborns), a descriptive cross-sectional design was adopted, using a standardised interviewer-administered questionnaire to collect data. Using a consecutive sampling technique, we enrolled 407 mothers to participate in the study. The overall KAPs of the study participants were assessed using the sum score of each outcome based on Bloom's cut-off point. Completed data was then analysed using descriptive statistics with SPSS version 22.0 at the level of P < .05. Out of the 407 participants, 321 (78.9%) had not heard about Ophthalmia Neonatorum with nearly 93% having low levels of knowledge on the neonatal infection. We found a significant association between formal education (P = .001), skilled occupation (P = .008) and a high level of knowledge on Ophthalmia Neonatorum. The study highlights the need to find improved and alternative methods of educating mothers on Ophthalmia Neonatorum in the bid to reduce blindness attributed to the condition.

A study of Ophthalmia Neonatorum in the Central Reion of Ghana: Causative Agents and Antibiotic Susceptibility Patterns.

In developing countries such as Ghana, ophthalmia neonatorum (ON) remains a public health concern. This is because of its unknown etiology patterns, the growing concerns of antibiotic resistance strains and the contribution of ON to childhood blindness. This study was therefore conducted to determine the causative agents, risk factors and the antibiotic sensitivity patterns of micro-organisms associated with ON. A clinic-based prospective study was conducted in the Maternal and Child Health units of 6 health care facilities in the Central region of Ghana over a period of 17 months. Conjunctival swabs were taken from all neonates with clinical signs of ON. Isolation and characterization of bacteria were done using standard microbiological methods. Additionally, data were collected and analyzed on neonate's demographics and clinical features of ON. Microbial growth was recorded in 86 cases (52.4%) out of the 110 neonates assessed. Staphylococcus spp. (39.2% of all positive cultures) was the most common causative organism. No case of gonococcus was isolated. Delivery method, vaginal discharge, administration of prophylaxis and weight of neonate were the risk factors associated with the development of ON (P < .05). The level of resistance to Tetracycline was found to be 73%. Neonatal conjunctivitis is more likely to be acquired postnatal. Culture and sensitivity testing are required as an important guide for treatment. The commonest causative organism, Staphylococcus spp., were found to be resistant to Teteracyline, therefore is the need to consider alternatives measures in the prevention and control of ON.