Visual Acuity and Reproducibility of Visual Fields
Investigative Ophthalmology & Visual Science
Matsuura et al. investigated the association between visual acuity (VA) and the reproducibility of test-retest visual field (VF) measurements in glaucoma patients. They found that as VA declines, the reproducibility of VF tests declines as well, particularly when a patient’s logMAR VA is worse than 0.5.
For this retrospective study, the researchers evaluated 627 patients (627 eyes) who had open-angle glaucoma. All underwent Humphrey 24-2 or 30-2 VF tests twice within 3 months; the same mode was used for both tests. Refractive error was measured in –0.25 D steps. VA was calculated in logMAR (range, –0.18 to 1).
Based on their evaluation of the correlation between VF reproducibility and logMAR VA, the researchers noted that although VA is a useful parameter for assessing the reproducibility of VFs, its usefulness declines with greater refractive error. Therefore, they recommended a logMAR cut-off value of worse than 0.5 when using VF outcomes in glaucoma research or in monitoring progression or effects of interventions.
Eye Protection, Eye Injuries, and Field Hockey
Does wearing protective eyewear reduce the risk of injuries in field hockey players? Kriz et al. evaluated this issue in a group of female high school players and found that those who use the eyewear have a lower rate of certain eye injuries. However, the players remain at significant risk of experiencing a concussion.
For this retrospective study, the researchers analyzed data collected from national and regional databases 2 years before and 2 years after a national mandate for protective eyewear at the high school level was put into place in 2011. All told, 206 high schools were involved, accounting for a total of 624,803 athletic exposures (defined as 1 athlete participating in 1 practice or competition).
Within the 4-year time span, eye and orbital injuries dropped from 22 before the mandate to 8 after; these included eyebrow/eyelid lacerations, periorbital contusions, and corneal abrasions. With regard to concussions, 93 occurred before the mandate, and 116 occurred after it. Other head and facial injuries (excluding eye injuries and concussions) dropped from 97 to 79 in the study period. The authors noted that greater concussion awareness in recent years might have played a role in the higher number of concussions reported during the later study period.
The authors stated that their findings with regard to eye injuries support the mandatory use of protective equipment in field hockey at all amateur levels.
Tasimelteon for Sleep-Wake Disorder in the Blind
Published online Aug. 5, 2015
Lockley et al. evaluated whether once-daily oral tasimelteon could reset the circadian pacemaker in totally blind people with non–24-hour sleep-wake disorder. They found that the drug can synchronize, or entrain, totally blind people to a 24-hour circadian cycle, but it must be taken on an ongoing basis to sustain the benefits. The researchers conducted 2 phase 3 trials. Sixty-two patients completed the first study (known as SET), and 20 completed the second (known as RESET). Patients were randomized to receive either 20 mg of tasimelteon or placebo daily 1 hour before bedtime. Compared with the placebo group, a significantly higher percentage of patients taking tasimelteon had clinically meaningful improvements in the duration of nighttime sleep and reduced undesired daytime sleep. It also improved patients’ sleep stability and physicians’ ratings of patient functioning. However, results of the RESET trial indicated that continuing treatment with tasimelteon is necessary for circadian entrainment to be maintained.
Tasimelteon is a dual-melatonin receptor agonist, and it is the first drug to be approved by both the U.S. Food and Drug Administration and the European Medicines Agency for non–24-hour sleep-wake disorder.
Supplements and Cognitive Function in AREDS2 Participants
Chew et al. tested whether oral supplementation with omega-3 fatty acids and lutein plus zeaxanthin had any impact on cognitive functioning in patients with age-related macular degeneration (AMD). They found that it did not.
This study involved 3,741 of the 4,203 participants in the Age-Related Eye Disease Study 2 (AREDS2). Patients were randomized to receive either 1) placebo, 2) the omega-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid, 3) lutein/zeaxanthin, or 4) a combination of the fatty acids and lutein/zeaxanthin. They also received 1 of 4 AREDS supplements: 1) the original formulation, 2) a version without beta carotene, 3) a low-zinc version, or 4) a low-zinc, no–beta carotene formulation.
Validated cognitive function tests were administered at baseline and every 2 years during the 5-year study. No statistically significant effects were noted with regard to cognitive function when supplementation was compared with placebo.
However, the researchers noted several factors that limited the generalizability of the findings: The study population consisted of well-nourished, highly educated people; participants had at least intermediate or advanced AMD, which is a type of neurodegenerative disease; and supplementation might have been started too late in the aging process in this study population, which had a mean age at baseline of 72.7 years.
Roundup of Other Journals is written by Jean Shaw and edited by Deepak P. Edward, MD.
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American Journal of Ophthalmology