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). The virtual retinal display as a low-vision computer interface: a pilot study. Use of prisms for navigation and driving in hemianopic patients. Reading performance of geriatric patients post exudative maculopathy. Benefits of electronic vision enhancement systems (EVES) for the visually impaired. Reading with a head-mounted video magnifier. Comparing the 1CU accommodative, multifocal, and monofocal intraocular lenses: a randomized trial. Quality of life evaluation after implantation of 2 multifocal intraocular lens models and a monofocal model.
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. 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. (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 study was performed to evaluate any differences in reading speed and duration of comfortable reading speed in geriatric patients with post disciform stage exudative age-related macular degeneration (ARMD) or ocular histoplasmosis. Reading speed and duration with CCTV, illuminated stand magnifier, and spectacle lenses were compared for 37 patients in the Low Vision Program at the Central Blind Rehabilitation Center. Results indicate significantly faster reading speed with CCTV and spectacle lenses as compared to illuminated stand magnifiers. The difference between reading speeds measured with spectacle reading glasses and CCTVs was borderline significant. Patients read significantly longer with CCTVs than with spectacle lenses or illuminated stand magnifiers. No significant difference was found comparing spectacle lenses or illuminated stand magnifiers with regard to reading duration. 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. 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. To compare the binocular near vision performance in patients implanted with the 1CU accommodating intraocular lens (IOL) with a multifocal and monofocal IOL.
                Prospective, randomized, double-masked clinical trial.
                Ninety patients presenting for cataract surgery to the Department of Ophthalmology, Hillingdon Hospital were randomized to receive the 1CU accommodative IOL, a multifocal IOL, or a monofocal IOL (control group).
                Patients underwent bilateral sequential phacoemulsification with implantation of 1 of the 3 IOL types and were assessed at 3 and 18 months after second-eye surgery.
                Logarithm of the minimum angle of resolution distance and near visual acuities (VAs) (unaided and distance corrected), contrast sensitivity, and accommodative amplitude (near point and defocusing) were measured at 3 and 18 months. Reading speed was assessed at 18 months, and glare symptoms and spectacle independence were compared using a standardized questionnaire.
                Mean unaided and distance-corrected binocular near VAs were similar in the 1CU and multifocal and were significantly higher than the control group's (P<0.02). There was no significant difference in reading speed between any of the groups, but critical print sizes were similar in the 1CU and multifocal groups and significantly better than the control group's (P = 0.02). The accommodative range was highest in the multifocal group and lowest in the control group, and there was no significant difference between the 1CU and control groups for defocus or near point at 18 months. Of the 1CU group and control group, 71.4% and 63.2%, respectively, experienced no glare at 18 months, compared with only 25% of the multifocal group (P = 0.01). Of the 1CU group and multifocal group, 19% and 27.3%, respectively, were completely spectacle independent at 18 months; none of the control group was (P = 0.05).
                The 1CU accommodating IOL provides improved near vision compared with a monofocal IOL. There is a discrepancy between the near function and accommodative amplitude measured in the 1CU. The multifocal provides excellent near acuity, but photopic phenomena remain a problem inherent in the lens design. To compare vision-related quality of life using the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) in patients with 1 of 3 types of intraocular lenses (IOLs) and to correlate it with postoperative visual outcomes.
                Vissum Corporation-Instituto Oftalmológico de Alicante, Alicante, Spain.
                Comparative case series.
                This study comprised eyes having cataract surgery with bilateral implantation of a monofocal IOL (Group A), apodized multifocal IOL (Group B), or full diffractive multifocal IOL (Group C). Distance and near visual acuities, contrast sensitivity, and quality of life were evaluated preoperatively and postoperatively.
                The study enrolled 106 eyes (53 patients; age range 49 to 80 years). All groups had significant improvement in uncorrected and corrected distance visual acuities postoperatively (P ≤.05). Near vision outcomes were significantly better in Groups B and C (P ≤.01). Groups B and C had significantly less difficulty in some near tasks, such as reading the newspaper (A-B, P=.02; A-C, P=.02) or reading bills (A-B, P=.04; A-C, P=.004). Group C also had significantly less difficulty driving at night than Group B (P<.01). Near visual acuity and contrast sensitivity were significantly correlated with difficulty in near visual tasks in Groups B and C. Night-driving difficulty correlated significantly with contrast sensitivity in Group B.
                Patients with multifocal IOLs could perform several daily tasks at near and intermediate distances, with less night-driving limitation with the full diffractive IOL than with apodized multifocal and monofocal IOLs.
                No author has a financial or proprietary interest in any material or method mentioned.
                Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
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.