Utilization and Abandonment of Low Vision Devices Prescribed on a Mobile Clinic.

SIGNIFICANCE: Device utilization and abandonment for patients seen on a mobile clinic are explored. Findings are informative for resource allocation in a novel low vision rehabilitation (LVR) delivery model. This study also explores the relationships between device abandonment and LVR patient-reported functional outcomes. PURPOSE: This prospective cohort study investigated low vision device utilization and abandonment in a novel mobile clinic delivery model. METHODS: A device abandonment questionnaire was administered by telephone 3 months and 1 year after mobile clinic LVR. Participants (n = 65) had previously met the U.S. definition of legal blindness and were prescribed a total of 154 devices at their low vision consultative visits. Trends in device utilization and correlations with clinical and demographic participant characteristics, as well as functional outcomes as assessed by Massof Activity Inventory, are explored. RESULTS: An average of 2.6 device recommendations were made per participant. Digital magnification, optical magnifiers, and filters were most frequently recommended. At 3 months, 29% of participants abandoned at least one device, although only 17% of received devices were abandoned. There was no significant difference in the number of devices used, abandoned, or not received at 3 months versus 1 year after LVR. Devices prescribed for reading goals were most frequently used and least often abandoned, whereas glare control and distance magnification devices were more frequently abandoned. Neither patient characteristics nor Massof Activity Inventory change score was predictive of device abandonment. There was no significant difference in the odds of device abandonment in comparison with a previous study that assessed academic outpatient LVR clinics using the same questionnaire. CONCLUSIONS: Although more device recommendations are given per patient on the mobile clinic, there is no significant difference in device abandonment for patients seen on the mobile clinic versus other outpatient LVR delivery models.

Clinical outcomes of low vision rehabilitation delivered by a mobile clinic.

PURPOSE: This prospective cohort study examined clinical outcomes of low vision rehabilitation (LVR) delivered by a mobile clinic. METHODS: Participants were recruited from those scheduled for mobile clinic LVR and met the United States definition of legal blindness. Participants completed the Massof Activity Inventory (AI) before LVR, 3 months post-LVR, and 1 year post-LVR. Change scores and measures of clinical effect (i.e. Cohen's effect size and minimum clinically important difference, MCID) were calculated for each time point and compared. Additional participant characteristics (age, acuity, contrast sensitivity, cause of visual impairment, training recommendations, and prior LVR experience) were also explored with respect to outcome measures. RESULTS: Of the 66 participants enroled in this study, 47% had no prior LVR experience. Significant differences were noted between baseline and 3-month person measures, and between baseline and 1-year person measures. There was no significant difference between 3-month and 1-year person measures, nor was there a significant difference in change score between these two time points. At 1 year post-LVR, overall visual ability effect size was 0.74. A clinically meaningful outcome was achieved in 56% of participants at 3 months and 71% at 1 year for overall visual ability. There was no significant difference in the proportion of participants achieving MCID at 3 months vs 1 year. Of participants who completed the 1-year post-LVR AI, 59% reported a subjective worsening of vision during the study period. This subgroup also tended to have smaller 1-year change scores. CONCLUSIONS: Mobile clinic LVR is effective at expanding access to care and produces clinically meaningful outcomes comparable to those seen in other outpatient LVR delivery models.

Abandonment of low-vision devices in an outpatient population.

PURPOSE: To investigate abandonment rate of prescribed low-vision devices for near tasks and factors associated with abandonment in a U.S. outpatient population. METHODS: A telephone survey was administered to 88 patients with low vision from four clinical sites about 1 year after examination and prescription of devices. Patients were surveyed on timing and frequency of use and reasons for abandonment of devices. The main outcome measure (abandonment) was defined as patient report of no use of prescribed device in the previous 3 months. Multivariate logistic regression was used to investigate significant vision and demographic factors related to abandonment. RESULTS: Of 119 prescribed devices, 19% (95% CI, 12 to 26) had not been used within the previous 3 months. Mean (±SD) better eye visual acuity at examination was 0.61 ± 0.29 logMAR, and mean age was 77 ± 17 years. Mean time between device prescription and survey was 11 ± 3 months. Device abandonment was not associated with age (p = 0.863), time since prescription (p = 0.125), visual acuity (p = 0.804), or category of magnification device (spectacle, handheld, stand, or video) (p = 0.412). There was a significant association between documented non-central visual field loss and abandonment of magnification device (p = 0.046). Repeat administration of the survey resulted in the same abandonment classification in 15 of 15 patients (100%). CONCLUSIONS: Abandonment rate was similar for this outpatient population to those previously reported in the U.S. veteran inpatient population and in other countries. Patients with visual field loss may be more likely to abandon prescribed devices.

Survey of optometric low vision rehabilitation training methods for the moderately visually impaired.

PURPOSE: The goal of this survey study is to determine the low vision rehabilitation training practices of optometrists who prescribe near magnifying devices for low vision patients who have moderate visual impairment from age-related macular degeneration. METHODS: A total of 2,028 surveys were sent electronically or by mail. A total of 136 optometrists reporting a special interest in low vision rehabilitation responded to an 18-item survey about practice mode, educational background, affiliations, and other demographic information. They were queried on methodology, frequency, and specific strategic content of rehabilitation training. RESULTS: Sixty-eight percent of the 136 respondents were private practitioners. Fifty-four percent of all respondents agreed that they train patients for 1 hour or less. Nine percent provided 3 or more training visits and were more likely to utilize an occupational therapist. Forty-six percent of respondents reported using various other personnel to perform the training. The majority of respondents spend 25% of their time examining low vision patients. Eighteen percent of all respondents were low vision residency trained. CONCLUSIONS: Descriptions of current practice patterns are difficult to ascertain without consensus on terminology and management criteria among low vision practitioners. This survey and accompanying literature review support the need for clinical research and education that will establish an efficacious and cost-effective model for private outpatient low vision rehabilitation for individuals with various levels of vision impairment to determine the true availability of low vision rehabilitation care in the United States.

Low vision rehabilitation for a target-shooting marksman with visual field loss and diplopia.

BACKGROUND: In the United States in 2006, there were 17.8 million hunters and 17.1 million target shooters. When these sportsmen suffer significant visual loss, it can have a devastating effect on their participation in the shooting sports. According to the National Rifle Association, there are no reliable data sources on the number of target shooters with visual impairment. This case report describes a retired, nationally ranked, competitive target shooter who suffered bilateral visual field loss secondary to nonarteritic anterior ischemic optic neuropathy and diplopia secondary to cerebral vascular accident. CASE REPORT: A retired 67-year-old white man was referred by a local optometrist to a neuro-ophthalmologist with a suspicious finding of disc pallor and a restriction of the visual field. Examination revealed right hypertropia and visual field defects: binocular superior altitudinal losses and inferior arcuate loss in his dominant, right eye. He had best-corrected distance acuity of 20/20 - 2 in the right eye and 20/25 - 2 in the left eye. Because of this, he received several adaptive rehabilitation devices to help him regain his shooting performance. These included a single-vision add for the pistol sight, yellow tint, low-power telescope, and patching. In this report, the fundamentals of eye care for competitive shooting are described with an emphasis on providing the best acuity for presbyopic patient prescriptions at nonstandard distances and the avoidance of diplopia. CONCLUSION: A visually impaired sportsman who participated in shooting sports at a high level was attempting to return to his previous shooting performance. This case report shows how sports vision and low vision rehabilitation techniques can improve the visual function of a competitive shooter.

Scanning eye movements in homonymous hemianopia documented by scanning laser ophthalmoscope retinal perimetry.

Sparing or partial recovery of visual fields in hemianopic patients is frequently difficult to document. This is because when testing large field losses, the standard automated or manual visual field testing systems have limited fixation controls. Measured visual field recovery in these cases may not be real but instead may be due to an artifact such as scanning eye movement. This article illustrates a way to separate the actual visual field sparing from scanning eye movement artifact by using perimetry testing with the scanning laser ophthalmoscope (SLO). During the SLO perimetry, the examiner has a direct and magnified view of the retinal fixation locus. This direct view allows for the added ability to monitor the fixation stability during target presentation. When eye movements larger than 1 degrees are noted, the examiner can repeat the trial. During static perimetry, our SLO records the retinal position of the fixation target at the end of the stimulus presentation and corrects scanning eye movements that occur during stimulus presentation. These special features enable us to identify when the apparent sparing of the visual field is due to the artifact of scanning. To demonstrate this, we selected the records of four hemianopic patients whose fields were examined by both standard perimetry and the SLO. We then compared the clinical visual fields with the SLO perimetry fields. One of the patients had a complete homonymous hemianopia on both the clinical perimetry and the SLO perimetry. A second patient was found by the SLO to have unstable fixation during testing. The SLO perimetry revealed that the apparent spared fields seen in standard perimetry were the result of eye scanning and not an actual enlargement of the visual field. Two other patients were confirmed by the SLO findings to have valid partial recovery of the visual field, one with and one without scanning eye movements. The advantages and limitations of SLO perimetry in analyzing hemianopic field sparing are discussed.