The Experience of a Randomized Clinical Trial of Closed-Circuit Television versus Eccentric Viewing Training for People with Age-Related Macular Degeneration

Abstract

Introduction In addition to optical devices, closed-circuit televisions (CCTVs) and eccentric viewing training are both recognized interventions to improve reading performance in individuals with vision loss secondary to age-related macular degeneration. Both are relatively expensive, however, either in the cost of the device or in the amount of time personnel need to provide training. In this randomized trial, we compared the effectiveness of these two interventions. Methods Participants with age-related macular degeneration and visual acuity between 6/48 (20/160) and 6/120 (20/400) first received basic low vision care, including optical devices. At the subsequent baseline visit, they undertook a battery of measures including logMAR visual acuity; reading speed and accuracy for text in 1.3M and 1M fonts; reading information on medicine bottles, utility bills, and food packages; the NEI-VFQ; the Geriatric Depression Scale; and a reading inventory questionnaire. They were then randomized to either obtaining a CCTV for home use or eccentric viewing training over the following six weeks. Results Recruitment was more difficult than expected for this population. Of 145 patients referred, 29 met the inclusion-exclusion criteria, 14 were willing to enroll, and 10 completed the trial. For the primary outcome (reading speed for 1.3M print), there was a significant improvement between baseline and outcome for the CCTV group (p = 0.005), but not for the eccentric viewing training group (p = 0.28), and the CCTV group showed significantly greater change (p = 0.04). There was a nonsignificant improvement in reading speed for 1M text and a decrease in the amount of time taken to read utility bill information in the CCTV group. There was a significant improvement in near visual acuity with current glasses with eccentric viewing training. The other measures did not reach statistical significance. Discussion Randomized clinical trials for low vision rehabilitation, particularly in the elderly population with vision loss, are challenging, but such trials are important for the allocation of resources. This trial showed early indications of more impact on reading performance from CCTV than eccentric viewing training.

Low Vision Devices for Age-Related Macular Degeneration: A Systematic Review

“…Five studies comparing different low vision devices to one another showed that all the devices generated improvements on the measured outcome (low quality evidence). 35,76,[92][93][94] The findings of two of these studies also indicated larger improvements with some devices (e.g. CCTV) instead of others (low quality evidence).…”

“…Alternatively, it was transparent that a limitation of almost all the studies was the lack of control groups (criteria four)only four studies were randomized control trials. [34][35][36][37] While within-group designs are common in this field of study, the internal validity of the studies may be biased. PRISMA flow diagram for low vision device studies in macular degeneration populations.…”

“…Another study found that the use of CCTV by itself was more effective than repeated training sessions. 35 Moreover, a randomized control trial of three rehabilitation programs for newly diagnosed AMD participants found that participants experienced no more benefits to quality of life or ability to carry out everyday activities, from any specific rehabilitation model over another. 37 Participants instead reported significantly worse scores on vision and health related quality of life questionnaires at a twelve month follow upalthough these negative changes might not be due to the rehabilitation programs, but once again caused by the progression of AMD.…”

“…CCTV) instead of others (low quality evidence). 35,76 Culham et al 93 concluded that younger people with visual impairments can benefit from head-mounted devices (i.e. Jordy, Maxport) more than older people, but generally traditional low vision devices (i.e.…”

“…This is demonstrated in Appendix B such that many studies investigated magnifiers and yet only four studies examined head-mounted devices. [34][35][36][37] It is possible that the scientific world has not yet caught up with the changing technological world and research on these devices in AMD populations is still to come.…”