Vision rehabilitation for age-related macular degeneration

What do eye care workers do when their patients go blind?

Sometimes even with the best efforts by the eye care worker (ECW), patients cannot be stopped from losing vision even in the best of centers anywhere in the world. However, in developing countries, most vision loss happens in rural and suburban areas away from where ECWs are majorly located due to poor facilities, adverse living conditions, and poverty. Once irreversible blindness happens, rehabilitation should follow. However, the numbers of those who are not referred for rehabilitation by far outstrips those who are, for various reasons. To find out why this is so, 150 ECWs with 1:2 M:F ratio were contacted through Google links sent through WhatsApp groups. Glaucoma was statistically the commonest cause of irreversible blindness (χ2 = 66.17, p-value < .0001) mostly from late presentation ( n = 146 of 150 responses, 97.7%). When patients go blind, most ( n = 132, 87.4%) of the ECW advise them to go to a blind school (81.2%). Only about a quarter of the respondents properly ensure that they go. A third admitted ( n = 78, 39%) that knowing the patients personally improved their willingness to refer. Many do not think the government is doing enough to help the blind ( n = 118, 78.7%). Even though many ECWs have given sensitization talks on blindness (124 of 164 responses), very few focus on what happens after blindness occurs (42.4% of respondents). A third of the ECW admitted to not doing enough for the blind in their practice ( n = 51, 34%). Majority have, however, heard about The Lens Eye Clinic (TLEC) rehab center, one of the foremost rehabilitation centers for the blind in Nigeria ( n = 103, 68.7%). ECW should ensure those who live in rural areas have poor socioeconomic background, less educated, female, elderly, or born blind should have regular screening and awareness programs in the areas of practice to catch the condition on time with provision made for early counseling and support services.

[The influence of visual rehabilitation on secondary depressive disorders due to age-related macular degeneration. A randomized controlled pilot study]

BACKGROUND

Age-related macular degeneration (AMD) often leads to visual impairment, loss of reading ability, reduced quality of life and secondary depression. The present study examined if visual rehabilitation has a preventive effect on secondary depression in these patients.

MATERIAL AND METHODS

In a controlled pilot study 20 patients were randomized into 2 groups whereby 9 underwent visual rehabilitation at first examination and 11 received magnifying visual aids only after 3 months. Psychosocial status was assessed by the geriatric depression scale (GDS) and the German version of the Centre for Epidemiologic Studies depression (CES-D) scale (main outcome parameter), cognitive status by the dementia detection test (DemTecT), minimental status (MMS) and quality of life by the National Eye Institute visual function questionnaire (NEI-VFQ 25). Ophthalmological examination included reading speed measurement by standardized texts (International Reading Speed Texts; IReST).

RESULTS

Parameters of the CES-D scale, DemTect and the subitem exercise of social roles of the NEI-VFQ 25 emerged in a divergent manner. Patients of the rehabilitation group became less depressive and improved in cognitive and social abilities and in the control group vice versa. The interactive effect of group and time was statistically significant for all three tests.

CONCLUSIONS

Visual rehabilitation has a positive impact on depression as well as cognitive status and quality of life in patients with AMD. The effects have to be confirmed in future studies with more patients and a longer observation period.

Influence of background on image recognition in normal vision and age-related macular degeneration

PURPOSE

The influence of background attenuation on the spatial frequency bandwidth requirements for image recognition was assessed in normal young and older groups and in a group with age-related macular degeneration (AMD). Bandwidth requirements were also assessed in the visual periphery of young normal observers.

METHODS

In Experiment 1, each observer was presented with 20 series of images. Each series consisted of a sequence of progressively low-pass filtered images, presented in an order of increasing bandwidth, i.e., according to an ascending method of limits. For half of the series, the background of the base image was selectively darkened by 80% of its original luminance. Three measures were analyzed: (1) the critical bandwidth defined as the bandwidth in cycles/image (cpi) at which 50% of the images were recognized, (2) the minimal bandwidth, defined as the minimal bandwidth at which images were recognized and (3) the proportion of images recognized at full bandwidth. In Experiment 2, young normal observers were similarly tested in central vision and at 5.5° eccentricity (superior or inferior visual field). A third background attenuation condition was included, as well, in which the background was low-pass filtered.

RESULTS

The critical bandwidth for image recognition was significantly reduced by darkening the image background for normal young and old and the AMD groups. This improvement was found to be contrast dependent for the darkened background. In addition, AMD observers tended to recognize more images at full bandwidth if the background was darkened. For normal young observers, making the background low-pass was ineffective in lowering the critical bandwidth in the fovea. Fewer images were recognized at full bandwidth at 5.5° eccentricity for a low-pass background and marginally fewer for a darkened background.

CONCLUSIONS

Selective attenuation of the image background can lead to reductions in the bandwidth requirements for image recognition in AMD. However, performance of young normal observers for images presented in the periphery was unlike AMD performance under the conditions investigated. These results have interesting implications for the design of image enhancement algorithms to aid low vision observers.

Burden of illness of bilateral neovascular age-related macular degeneration in Spain

BACKGROUND

The burden of illness, including health resource utilization and costs associated with bilateral neovascular age-related macular degeneration (Nv-AMD), was assessed in Spain.

PATIENTS AND METHODS

As part of an international prospective, case-controlled study, 89 Spanish patients with bilateral Nv-AMD were recruited by retina specialists and 96 Spanish control subjects were recruited by general practitioners and ophthalmologists. Physicians recorded clinical data and visual acuity (VA). In a subsequent telephone interview, Nv-AMD patients and controls completed the National Eye Institute Visual Function Questionnaire (NEI VFQ)-25, the EuroQol (EQ-5D), and the Hospital Anxiety and Depression Scale (HADS) questionnaire. Annual vision-related and non-vision-related medical costs and non-medical-related costs were calculated from study-specific questions.

RESULTS

The mean age was 76.2 years for Nv-AMD patients and 61.9 years for control subjects. The adjusted mean (95% CI) NEI VFQ-25 summary score was 51.9 (48.5; 55.4) for Nv-AMD patients and 87.7 (85.5; 89.9) for control subjects (p<0.05). The summary score of Nv-AMD patients decreased significantly with VA declination. Mean direct vision-related medical and non-medical-related costs were significantly greater for Nv-AMD patients than the control subjects, whereas non-vision-related medical costs were similar between groups. The total mean annual resource utilization cost was euro5733 for Nv-AMD patients compared to euro1070 for control subjects (p<0.0001).

CONCLUSIONS

Although the study design is subject to a number of limitations, patients with Nv-AMD in Spain have worse quality of life outcomes, greater depression, and higher healthcare costs as compared with similarly-aged individuals who are not affected by this disease.

Quality of life and health economic assessments of age-related macular degeneration

In this article, we review measures of patient-reported outcomes that can show whether a treatment for age-related macular degeneration also provides patient-perceived benefits. In addition, we look at health economic measurements currently being used to develop cost-effectiveness models for age-related macular degeneration.

Adaptation au scotome central. Partie I

Among the different means to adapt to central scotoma is eccentric fixation in several zones, the most documented and best-known phenomenon. After anatomic destruction of the macula, one area of the perifoveal retina may become the new oculomotor reference. This area is referred to as the preferred retinal locus (PRL). Scanning laser ophthalmoscopy greatly facilitated the analysis of these preferred retinal loci. However, the mechanisms involved in establishing the PRL remain insufficiently known. Furthermore, there may be several PRLs, which differ depending on the fixated target. PRL stability may also differ greatly among patients. The present review analyzes published data on the location of the preferred retinal loci, their number, and the factors that favor their occurrence. Methods to study the PRL and the relationship of the PRL with the visual cortex are also analyzed.

Modified astigmatism dial diagram for locating eccentric fixation in patients with central scotoma

PURPOSE

Patients with central scotoma often develop eccentric fixation on a preferred retinal locus (PRL). Identifying the PRL is one of the first steps in low vision rehabilitation training. We present our evaluation of a simple test designed to locate the eccentric fixation in eyes with central scotoma.

METHODS

This was a prospective case series of consecutive patients with age-related macular degeneration and bilateral central scotoma. A numeral was added in the center of an astigmatism dial diagram. After one eye was patched, patients with central scotoma were asked to fixate the dial and describe it, then to look at the 12 o'clock position, and then around the clock. The eccentricity at which the central numeral was best seen was compared with the one determined by scanning laser ophthalmoscopy (SLO). The modified astigmatism dial test and SLO were done independently by two masked investigators. The results of the two methods were expressed in clock hour positions and were considered to be in agreement when they did not differ by more than one hour.

RESULTS

Nine consecutive patients (18 eyes) with severe age-related macular degeneration and bilateral central scotoma were tested. The six women and three men ranged in age from 61 to 86 years (mean 75.8 years). The pattern test correlated with SLO findings in 12 (66%) of the 18 eyes. When considering the best-seeing eye of each patient, results showed agreement in eight (88%) out of nine cases.

CONCLUSIONS

The modified astigmatism dial test appears useful for establishing the location of the eccentric fixation in the best-seeing eye of patients with bilateral central scotoma, allowing visual rehabilitation training to be started without delay.

Age-related macular degeneration: cost-of-illness issues

Macular degeneration refers to the breakdown of cells in the centre of the retina. Some degeneration is an inevitable consequence of the aging process; however, when this is associated with loss of sight in the central part of the field of vision an underlying pathology is considered present. Among those aged 55 years, the prevalence of the disease in the US was estimated at 1% rising to approximately 15% among those aged 80 years. Other studies estimate the prevalence of the disease to be higher and to be increasing. The main effect of the disease is to reduce the ability of the individual to engage in everyday activities that require clear central vision. It may also be associated with elevated risks of depression and increased levels of dependency. Currently there is no effective treatment for the majority of patients. For a minority (< 10%) laser photocoagulation therapy may be effective in reducing the risk of severe vision loss. Another treatment, photodynamic therapy, is in development and many others are at an experimental stage. This review sought to establish current knowledge on the cost of illness associated with age-related macular degeneration (ARMD). A search of the literature, together with direct communication with researchers in related fields and patient support/advocacy groups, was undertaken to ascertain current knowledge on the cost of illness of ARMD. While literature on the disease is extensive and literature on treatments is emerging, no substantive information on direct or indirect costs was found although evidence that loss of earnings may occur is beginning to emerge. Some information does exist on cost of illness in diabetic retinopathy, a disease with similarities to ARMD, though even for this disease gaps in knowledge are apparent and wide variations exhibited. Given current knowledge, it is not possible to report on the cost of illness for ARMD with confidence. The lack of information on the cost of illness in ARMD presents difficulties for researchers and policy makers in assessing the cost effectiveness of the existing treatment, as well as new treatments as they become available. Given developments in treatments and the increasing prevalence of the disease, it is important that cost-of-illness information is gathered for ARMD.