Clinical performance of electronic, head-mounted, low-vision devices. A comparison of patient reading performance and preference: optical devices, handheld CCTV (Innoventions Magni-Cam), or stand-mounted CCTV (Optelec Clearview or TSI Genie). Benefits of electronic vision enhancement systems (EVES) for the visually impaired. Use of prisms for navigation and driving in hemianopic patients. The virtual retinal display as a low-vision computer interface: a pilot study. Reading with a head-mounted video magnifier. The TCu380A, TCu220C, multiload 250 and Nova T IUDS at 3,5 and 7 years of use--results from three randomized multicentre trials. World Health Organization. Special Programme of Research, Development and Research Training in Human Reproduction: Task Force on the Safety and Efficacy of Fertility Regulating Methods. Locking devices on cigarette vending machines: evaluation of a city ordinance. Fibre optic versus conventional phototherapy for hyperbilirubinaemia in preterm infants.
This study compared four electronic head-mounted devices (HMDs) (Jordy, Flipperport, Maxport and NuVision) with conventional optical low-vision aids (LVAs). The aim was to determine any performance differences for laboratory-based clinical measurements and practical visual tasks for patients with macular disease. Possible factors influencing success were explored. Ten patients with early onset macular disease (EOMD) and 10 with age-related macular disease (AMD) used the four HMDs, habitual spectacles and previously prescribed optical LVAs to complete a range of clinical measurements and everyday visual tasks. The clinical measurements were distance, intermediate and near acuities, and contrast sensitivity. The visual tasks were to read text of three sizes, to write a cheque and to identify grocery items on a shelf. Following the initial evaluation, each subject took home two randomly selected HMD devices for 2 weeks, after which performance measures were repeated. No single HMD stood out as being superior overall. Flipperport and Jordy provided significantly better distance and intermediate acuity than the previously prescribed optical LVAs but near acuity and contrast sensitivity were not consistently better with any of the HMDs. Practice at home provided some improvement in performance with HMDs, nevertheless, optical aids remained the best devices for optimum functioning for the majority of tasks. Younger patients and those with better distance acuity were more likely to benefit from HMDs, particularly when reading small print. In low vision clinics, practitioners should continue to show patients conventional optical aids and demonstrate these electronic HMDs only when appropriate for the individual patient. Clinicians frequently prescribe reading devices for low vision patients having a central field loss. This study seeks to provide comparative information the clinician can use to assist patients in selecting the most cost-effective device(s) for reading.
                In this study we compared optical devices with two types of closed-circuit televisions (CCTVs) that differed in two important characteristics: price, and whether the camera was stand-mounted with an X-Y table or whether the camera was handheld. A "within-subjects" design was used with 22 subjects. The primary comparisons between devices were subject reading speed, duration, and preference.
                Subject reading speed and duration were significantly greater with the CCTV systems than with optical devices; however, no significant performance differences were found between the two types of CCTVs. Patients did express a clear preference for one versus the other type of CCTV, with an overall preference for the stand-mounted system. When asked to consider the price differential between types of CCTVs, patient preferences were about equally divided.
                Clinicians can expect significantly better initial reading performance for patients with central visual-field losses when reading with CCTVs versus optical devices. Handheld CCTVs, when compared with stand-mounted systems, are less expensive, provide equal performance, and have slightly lower subject preference ratings. The current study provides clinicians with objective performance data and subjective preference data that can be used to help patients with central visual-field losses select the most cost-effective reading device. To examine whether objective performance of near tasks is improved with various electronic vision enhancement systems (EVES) compared with the subject's own optical magnifier.
                Experimental study, randomized, within-patient design.
                This was a prospective study, conducted in a hospital ophthalmology low-vision clinic. The patient population comprised 70 sequential visually impaired subjects. The magnifying devices examined were: patient's optimum optical magnifier; magnification and field-of-view matched mouse EVES with monitor or head-mounted display (HMD) viewing; and stand EVES with monitor viewing. The tasks performed were: reading speed and acuity; time taken to track from one column of print to the next; follow a route map, and locate a specific feature; and identification of specific information from a medicine label.
                Mouse EVES with HMD viewing caused lower reading speeds than stand EVES with monitor viewing (F = 38.7, P <.001). Reading with the optical magnifier was slower than with the mouse or stand EVES with monitor viewing at smaller print sizes (P <.05). The column location task was faster with the optical magnifier than with any of the EVES (F = 10.3, P <.001). The map tracking and medicine label identification task was slower with the mouse EVES with HMD viewing than with the other magnifiers (P <.01). Previous EVES experience had no effect on task performance (P >.05), but subjects with previous optical magnifier experience were significantly slower at performing the medicine label identification task with all of the EVES (P <.05).
                Although EVES provide objective benefits to the visually impaired in reading speed and acuity, together with some specific near tasks, some can be performed just as fast using optical magnification. (1) To compare the outcomes of orientation and mobility and driving training with Fresnel prisms and the Gottlieb Visual Field Awareness System for patients with homonymous hemianopsia, and (2) To determine whether the patients continue to use the optical enhancement devices at a 2-year follow-up point.
                Patients with homonymous hemianopsia were provided with a rehabilitation program where they were fitted with prism lenses and trained to use them for navigation and driving. Telephone interviews were used to obtain information about device usage 2 years following the completion of the training program.
                Patients' performance was compared with a test-retest criterion in the visual skills areas of recognition, mobility, peripheral detection, scanning, tracking, and visual memory. Patients with hemianopic loss showed improvements in all of the visual skills categories, ranging from the highest improvements of 26% of tasks improved in the mobility category to 13% in the recognition category. The majority of the hemianopic patients reported using the devices at the 2-year follow-up interview.
                The patients with homonymous hemianopsia showed improvements in visual functioning using prism lenses, although these improvements were smaller than those found in previous studies with central or bilateral peripheral vision loss groups who were trained to use other optical enhancement devices for navigation and driving using a similar curriculum. However, given the evidence of increased risk of accidents for patients with peripheral vision loss, the safety of peripheral enhancement devices for driving must be thoroughly evaluated before their impact on public safety is known. This pilot study examined the performance of an alternative computer visual interface, the Virtual Retinal Display (VRD), for low-vision use. The VRD scans laser light directly onto the retina, creating a virtual image. Since visually impaired individuals can have difficulty using computer displays, a matched comparison study was done between the VRD and the standard cathode ray tube (CRT) monitor. Reading speed and acuity tests were collected from 13 low-vision volunteers selected to represent the broad range of partially sighted individuals actively involved in the work force. Forty-six percent of subjects had highest visual acuity while viewing the VRD; 30% of subjects had highest acuity viewing the CRT; and 24% of subjects had equal acuity across the two displays. Although mean reading speed across all 13 subjects indicated no significant difference between displays, individual subjects with predominantly optical causes of low vision exhibited clinically important increases in reading speed versus the CRT. However, most subjects with predominantly retinal damage showed a slight disadvantage using the VRD. We give theoretical explanation to the bifurcated results and conclude that for a subset of low-vision users, the VRD technology is very promising as a basis for future low-vision aids. This study compared the effectiveness of a head-mounted video magnifier, low-vision enhancement system (LVES), with closed-circuit TV (CCTV) and large print as a device or means of improving reading performance in people with low vision.
                The reading performance of ten low-vision participants was assessed in two ways: (1) By measuring reading speed as a function of print size with LVES and without LVES, and (2) by comparing reading speed and comprehension of news articles using the LVES vs. a popular non-head-mounted video magnifier, the CCTV.
                Maximum reading speeds with LVES matched the maximum reading speeds with unaided vision attained by enlarging print. The critical print size (the smallest print size that could be read at maximum reading speed) improved significantly for all participants using LVES compared with unaided vision. When comparing reading performance using LVES and CCTV, we found that reading speed and comprehension for the two conditions were equivalent. The two low-vision participants with lowest acuities (20/640 and 20/960) could not read the 10-point newspaper articles with LVES, even with an 8 D auxiliary reading lens that permitted a very close reading distance.
                Head-mounted video magnifiers, such as LVES, can support good low-vision reading performance, but the restricted range of magnification may limit the usefulness of the device as a reading magnifier for people with very low acuity. The WHO Special Programme of Research, Development and Research Training in Human Reproduction has conducted between 1979 and the present, three randomized comparative clinical trials of the TCu220C, Multiload 250, Nova T and TCu380A devices in 24 centres in 14 countries. The comparative study of the TCu220C and the Multiload 250 devices was completed after three years of use with no significant differences in event rates between the devices (three-year cumulative pregnancy rates of 1.7% and 2.8%, respectively). The Nova T device was discontinued from the comparative study with the TCu220C after five years of use having shown significantly higher cumulative pregnancy rates at three and at five years of use-6.6% and 12.3%, respectively, compared to 4.4% and 6.6%, respectively, for the TCu220C. In the comparative study of the TCu220C and TCu380A, the latter device had significantly lower cumulative pregnancy rates of 1.0%, 1.4% and 1.6% at three, five and seven years of use, respectively (comparative results for the TCu220C: 3.4%, 4.0% and 4.9%, respectively). It is suggested that the TCu380A life span be extended to at least seven years of use and the device be considered as a non-surgical, potentially reversible, alternative to tubal ligation for women needing long-term fertility regulation. Policymakers, researchers, and citizens are beginning to recognize the need to limit minors' access to tobacco by restricting the sale of cigarettes through vending machines. One policy alternative that has been proposed by the tobacco industry is a requirement that vending machines be fitted with electronic locking devices. This study evaluates such a policy as enacted in St. Paul, Minn.
                A random sample of vending machine locations was selected for cigarette purchase attempts conducted before implementation and at 3 and 12 months postimplementation.
                The rate of noncompliance by merchants was 34% after 3 months and 30% after 1 year. The effect of the law was to reduce the ability of a minor to purchase cigarettes from locations originally selling cigarettes through vending machines from 86% at baseline to 36% at 3 months. The purchase rate at these locations rose to 48% at 1 year.
                Our results suggest that cigarette vending machine locking devices may not be as effective as vending machine bans and require additional enforcement to ensure compliance with the law. Studies comparing efficacy of fibre optic phototherapy to conventional phototherapy are performed mostly in term infants and give conflicting results. This randomized prospective study compares efficacy of fibre optic phototherapy using the Ohmeda Biliblanket device to conventional fluorescent phototherapy in preterm infants. A total of 124 preterm infants with a nonhaemolytic hyperbilirubinaemia were evaluated. Stratification at randomisation was performed according to birth weight ( < 1000 g, 1000-1500 g or 1500-2000 g). Fifty-six infants received fibre optic and 68 conventional phototherapy. Efficacy was assessed by comparing the required duration of phototherapy. Median duration of phototherapy was 118 h and 114 h in the fibre optic and conventional groups respectively, the difference in which was not statistically significant. The median durations were also not significantly different within the separate weight groups. The number of infants requiring exchange transfusions was similar in both treatment groups.
                The efficacy of fibre optic phototherapy in preterm infants is comparable to conventional phototherapy.
Further research is needed on the comparison of different types of low vision aids. It will be also necessary to delineate patient's characteristics that predict performance with costly electronic devices as well as their sustained use in the long term compared to simpler and cheaper optical devices.