Loss of vision

2018 ◽  
Author(s):  
Susan Mollan ◽  
Alastair Denniston
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Low Vision ◽  
Visual Field Loss ◽  
Age Related Macular Degeneration ◽  
World Health ◽  
Clinical Approach ◽  
Loss Of Vision ◽  
P Loss ◽  
Age Related

Loss of vision describes a reduction in vision that cannot be corrected by glasses or contact lenses. Patients who complain of changes in their vision may have loss of visual acuity, distorted vision, or visual field loss. The World Health Organization classifies visual impairment as blindness or low vision. Blindness is defined as visual acuity of less than 3/60 in the better eye. Low vision is present when the visual acuity is less than 6/18 but equal to or better than 3/60, in the better eye. The etiology of permanent visual loss is diverse and depends on the region studied. In the UK, the leading causes are age-related macular degeneration, glaucoma, diabetic retinopathy, optic atrophy, and cataract. This chapter describes the clinical approach to the patient with loss of vision.

scholarly journals Design Consideration for Developing Bio-potential Instrumentation Amplifier Intended for Bionic Eye.

2019 ◽  
Vol 9 (1S5) ◽  
pp. 115-117
Keyword(s):  
Video Processing ◽  
Low Vision ◽  
Ccd Camera ◽  
Age Related Macular Degeneration ◽  
World Health ◽  
Instrumentation Amplifier ◽  
Processing Unit ◽  
Noise Levels ◽  
Age Related ◽  
Bionic Eye

According to the Survey of WHO [World Health Organization] ,a people of about 285 million are visually impaired, 39 million are blind and 246 million are having low vision. Blindness is a serious ailment that makes people to suffer a lot. It occurs because of the eye related disorders like Retinitis Pigmentosa[RP], Age-Related Macular Degeneration[AMRD] and Glaucoma, resulting to lead an uncomfortable life style. Recent developments of the Biomedical Engineering field lead to the development of artificial human eye-Bionic eye analogous to natural eye. Bionic eye is a complex system which is integrated with many sub systems such as CCD camera, video processing unit, implantable chip , radio transmitter and receiver. The implanted artificial retina helps the patients of RP and AMRD regains the vision. Apart from this there exist limitations because of electrode count and noise levels. For better optimization to reduce noise levels of bio-potential signals an instrumentation amplifier is used. In this paper different Instrumentation amplifier are discussed.

scholarly journals Vision Rehabilitation in Patients with Age-related Macular Degeneration

2014 ◽  
Vol 3 ◽  
pp. RPO.S12364 ◽  
Author(s):  
Filippo M. Amore ◽  
Stefania Fortini ◽  
Valeria Silvestri ◽  
Marco Sulfaro ◽  
Alessia Pacifici ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Macular Degeneration ◽  
Visual Stimulation ◽  
Low Vision ◽  
Reading Speed ◽  
Age Related Macular Degeneration ◽  
International Agency ◽  
Visual Rehabilitation ◽  
Age Related ◽  
Fixation Stability

Background The aim of this study was to investigate the rehabilitative process and visual rehabilitation outcomes in patients with central vision loss due to age-related macular degeneration (AMD). Methods Ninety-five subjects with AMD selected from the attendees of the National Centre of Services and Research for the Prevention of Blindness and Rehabilitation of Low Vision Patients—International Agency for Prevention of Blindness—IAPB Italia Onlus, were evaluated for this retrospective study. Low vision examination included psychological counseling, best corrected visual acuity (BCVA), near visual acuity, Pelli-Robson contrast sensitivity, and fixation stability analysis. Once the clinical assessment was completed, patients attended a low-vision rehabilitative pathway based on visual stimulation, devices training and, if needed, psychological support. Required magnification and reading speed were also evaluated. Results For the whole sample, the mean BCVA of the better eye was 0.7 (±0.2) LogMAR and of the worse eye was 1 (±0.2) LogMAR. Restoring reading ability was the most important focus for the patients examined as it was requested by 85% of the whole sample. Mean power of optical magnifying aids for near activities was 10.6 (±9.1) positive spherical diopters. Mean reading speed for the whole sample was 33.1 (±18.2) words per minute (wpm) before visual rehabilitation sessions and increased to 55.2 (±33.1) wpm after visual rehabilitation path. To cope with distance difficulties, 78 distance refractive correction, 10 Galilean telescopes, and 7 Keplerian telescopes were prescribed. For intermediate distance activities, 22 compensation lenses and 10 Galilean telescopes were suggested. Moreover, PC magnifier softwares were prescribed to nine patients. Sixty-five polarized medical filters were prescribed to reduce glare of sunlight. Because of unstable fixation in their better eye (32.3% (±19.7) within 2° circle and 54.8% (±22.9) within 4° circle) and visual acuity < 1.2 LogMAR in the fellow eye, 38 subjects, before starting the devices training sessions, attended a bio-feedback rehabilitation session with flickering pattern stimulus. In these subjects, fixation stability increased significantly to 75.6 (±14.9) within 2° and 89.4 (±19.5) within 4° ( P < 0.05), respectively. Conclusions Attending a customized low-vision intervention based on a multidisciplinary approach seems to be effective for improving visual functions in AMD. Both optical/electronic magnifiers and specific visual stimulation program can enhance visual performances.

Long term outcomes in dry age-related macular degeneration following low vision rehabilitation interventions

2020 ◽  
pp. 112067212097362
Author(s):  
Yulia Pyatova ◽  
Monica Daibert-Nido ◽  
Samuel N Markowitz
Keyword(s):  
Visual Acuity ◽  
Low Vision ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Low Vision Rehabilitation ◽  
Fixation Stability ◽  
Functional Vision ◽  
Vision Rehabilitation ◽  
Distance Vision

Background: Age-related macular degeneration (AMD) is the leading cause of loss of vision in the older age groups. In the absence of a known therapy, low vision rehabilitation aims at preserving residual functional vision at optimal levels. Long term functional outcomes from Low Vision Rehabilitation (LVR) in AMD cases were never scrutinized in the past. This study brings some clarification in this matter. Methods: This is a retrospective case series study including data up to 2 years following the baseline visit. Low Vision Assessments included microperimetry testing and recommendations for low vision devices for distance vision. Outcomes measures selected for this study were best corrected distance visual acuity, fixation stability and preferred retinal locus (PRL) topography and LVR interventions. Results: Data on 17 patients with an average age of 89.2 ± 4.4 years was collected. In those with better vision than 20/400 loss of vision was about 1.4 letter per year as tested with ETDRS charts compared with losses of four letters per year in a population without LVR interventions. Fixation stability continued to deteriorate while PRL eccentricity seemed to remain the same. In about half of cases there was a change in the topographic location of the PRL to a different retinal quadrant. Conclusion: Long term, as expected, changes were noticed in visual acuity, fixation stability and PRL topography. However, it seems that LVR interventions for distance vision help patients retain significantly better functional vision at the 2 years follow up interval when compared to others.

scholarly journals Causes of visual impairment and blindness among the middle-aged and elderly in northern Jordan

2002 ◽  
Vol 8 (2-3) ◽  
pp. 404-408
Author(s):  
A. Haddadin ◽  
I. Ereifej ◽  
F. Zawaida ◽  
H. Haddadin
Keyword(s):  
Visual Acuity ◽  
Low Vision ◽  
The Elderly ◽  
Education Programme ◽  
Population Based ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Common Causes ◽  
Northern Jordan ◽  
Population Based Survey

Causes of bilateral low vision [BLLV] and bilateral blindness [BLB] were investigated among 720 outpatients aged > 45 years in Irbid, Jordan, between July 1999 and October 2000. All received full ophthalmic examinations. BLLV was defined as visual acuity < 6/18 but > 3/60 in the better eye; BLB as acuity < 3/60 in the better eye. The leading cause of BLB and BLLV was cataract. Refractive error was the second major cause of BLLV. Other common causes were diabetic retinopathy and glaucoma. Age-related macular degeneration was the single cause of BLB and BLLV for only 1.6% and 2.8% respectively. A population-based survey of BLB and BLLV in the elderly, yearly vision examinations and an ophthalmic education programme are recommended.

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

2017 ◽  
Vol 111 (4) ◽  
pp. 354-368 ◽  
Author(s):  
Susan J. Leat ◽  
Francie Fengqin Si ◽  
Deborah Gold ◽  
Dawn Pickering ◽  
Keith Gordon ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Macular Degeneration ◽  
Vision Loss ◽  
Low Vision ◽  
Reading Speed ◽  
Optical Devices ◽  
Reading Performance ◽  
Age Related Macular Degeneration ◽  
Eccentric Viewing ◽  
Age Related

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.

The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 (VA LV VFQ-48): Performance of the Italian version

2019 ◽  
Vol 30 (5) ◽  
pp. 1014-1018
Author(s):  
Ilaria Di Maggio ◽  
Gianni Virgili ◽  
Giovanni Giacomelli ◽  
Vittoria Murro ◽  
Giovanni Sato ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Visual Information ◽  
Low Vision ◽  
Reading Speed ◽  
Veterans Affairs ◽  
Age Related Macular Degeneration ◽  
Italian Version ◽  
Visual Functioning ◽  
Age Related ◽  
Patient Reported

Purpose: The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 is among the most validated tools to collect patient-reported outcomes in a low-vision population. We have aimed to conduct a pilot validation of the Italian version of the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48. Methods: The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 was translated using a standardized procedure and then administered to consecutive low-vision patients attending rehabilitation services in three centers. Patients were interviewed by a trained psychologist regarding the individual items of the tool. Results: We included 131 patients with a mean visual acuity of 0.91 logMAR (standard deviation: 0.42 logMAR), mostly affected by age-related macular degeneration. The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 showed high internal consistency (Cronbach’s alpha: 0.98) and good item-test and item-rest correlation (median: 0.73 and 0.71, respectively). Both the overall score and the subscale (reading, visual motor, mobility and visual information) scores significantly correlated with visual acuity, reading acuity and speed. Reading speed achieved the best absolute correlation with the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 scores (Spearman r: 0.39–0.49). Conclusion: The Italian version of the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 is a valid tool to assess patients attending low-vision services. Revising a few items may further improve the tool.

scholarly journals Low vision services: a practical guide for the clinician

2018 ◽  
Vol 10 ◽  
pp. 251584141877626 ◽  
Author(s):  
Parth Shah ◽  
Stephen G. Schwartz ◽  
Scott Gartner ◽  
Ingrid U. Scott ◽  
Harry W. Flynn
Keyword(s):  
Emotional Distress ◽  
Psychosocial Support ◽  
Low Vision ◽  
Visual Field Loss ◽  
The United States ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Improved Outcomes ◽  
Low Vision Rehabilitation ◽  
Mobility Training

Low vision has been defined by best-corrected visual acuity worse than 20/40 in the better eye, substantial visual field loss, or substantial loss of contrast sensitivity that cannot be corrected by refraction, medical treatment, or surgery. In the United States, low vision is most commonly caused by age-related macular degeneration, glaucoma, and diabetic retinopathy. Most patients with low vision are elderly, although patients of all ages – including pediatric patients – may be affected. Low vision may decrease a patient’s quality of life substantially, leading to emotional distress and possibly depression. Low vision specialists aim to maximize the remaining vision of a patient by providing optical aids, orientation and mobility training, psychosocial support, and other methods of rehabilitation. Innovations in technology and devices offer additional options in low vision rehabilitation. Clinicians should consider referral to low vision specialists when a patient has difficulty with reading, mobility, driving, recognizing faces, or suffers from emotional distress due to low vision. Early referral may lead to improved outcomes.

scholarly journals The impact of saffron (Crocus sativus) supplementation on visual function in patients with dry age-related macular degeneration

2016 ◽  
Vol 10 ◽  
Author(s):  
Abbas Riazi ◽  
Yunes Panahi ◽  
Ali Agha Alishiri ◽  
Mohammad Ahmad Hosseini ◽  
Ali Akbar Karimi Zarchi ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Macular Degeneration ◽  
Contrast Sensitivity ◽  
Visual Function ◽  
Low Vision ◽  
Age Related Macular Degeneration ◽  
Crocus Sativus ◽  
Control Group ◽  
Age Related ◽  
The Impact

The aim was to evaluate the impact of saffron supplementation on visual function in patients with dry age-related macular degeneration (ARMD). Fifty-four participants, 23 male and 31 female, with dry ARMD were assigned to one of the following two groups. The treatment group (n=29) consumed 50 mg saffron daily during a 3- month period, while 25 subjects served as the control group. Visual acuity, contrast sensitivity, and retinal thickness were measured at the beginning and at the end of the study. Quality of life was evaluated using the Melbourne Low Vision Index (MLVI) before and after treatment. Significant increases in visual acuity and contrast sensitivity were found in the saffron group but not in the control group. Changes in macular thickness were not statistically different between the two groups. Short-term consumption of saffron may slow down the progression of disease and improve visual function, especially contrast sensitivity, in patients with dry ARMD.

scholarly journals Four Years of Observation to Evaluate Autonomy and Quality of Life after Implantation of a High-Add Intraocular Lens in Age-Related Macular Degeneration Patients

2020 ◽  
Vol 11 (2) ◽  
pp. 448-456
Author(s):  
Andreas F. Borkenstein ◽  
Eva-Maria Borkenstein
Keyword(s):  
Quality Of Life ◽  
Visual Acuity ◽  
Low Vision ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Corrected Distance Visual Acuity ◽  
Near Visual Acuity ◽  
Dry Amd

Visual impairment resulting from advanced dry age-related macular degeneration (AMD) limits the ability to perform activities required for independent living and adversely affects quality of life. We aimed to determine changes in these parameters in patients with AMD-related geographic atrophy who underwent magnifying cataract surgery (MAGS) using a foldable, bifocal high-add intraocular lens (IOL). The high-add IOL (LENTIS® MAX LS-313 MF 80, Oculentis) was implanted in the better seeing or dominant eye of eligible patients with clinically significant cataract, best corrected distance visual acuity 1.3–0.5 logMAR (20/400–20/63), best corrected near visual acuity >0.8 logMAR (20/125), and stable advanced dry AMD. Self-reported feasibility of performing routine activities and change in quality of life were the main outcome measures. Eleven of 15 operated patients had complete follow-up to 48 months. There were no significant intraoperative or postoperative complications. AMD converted from dry to wet in 2 patients. All patients reported functional gains in the first 3–6 months after surgery, and 10/11 patients reported improved quality of life. From baseline to 48 months, functional performance remained improved in all patients, and quality of life remained improved in the 9 patients with stable AMD. Best corrected distance visual acuity and uncorrected near visual acuity improved in all cases after surgery. Conclusion: Implantation of the high-add IOL was safe and resulted in durable functional and quality of life benefits. To our knowledge, our report describes the longest prospective follow-up (4 years) of a series of patients undergoing MAGS for rehabilitation of low vision related to advanced AMD. Data are needed from larger cohorts, but our experience supports giving consideration to MAGS in appropriately selected patients with low vision related to advanced dry AMD. We encourage further industry development of this technology and additional clinical research to collect more outcomes data to determine its potential to help patients maintain highly valued autonomy and quality of life.

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

2021 ◽  
Author(s):  
Anne Macnamara ◽  
Celia Chen ◽  
Andrew Davies ◽  
Charlotte Sloan ◽  
Tobias Loetscher
Keyword(s):  
Systematic Review ◽  
Visual Acuity ◽  
Macular Degeneration ◽  
Low Vision ◽  
Facial Recognition ◽  
Reading Performance ◽  
Conclusive Evidence ◽  
Age Related Macular Degeneration ◽  
Future Research ◽  
Age Related

Significance: Age-related macular degeneration (AMD) is a degenerative condition impacting central vision. Evaluating the effectiveness of low vision devices provides empirical evidence on how devices can overcome deficits caused by AMD and facilitates discussion on future improvements to vision enhancement technology.Methods: A systematic review of the literature was conducted on the use of low vision devices in AMD populations. Relevant peer-reviewed research articles from six databases were screened.Results: The findings of thirty-five studies revealed a significant impact of low vision devices leading to improvements in visual acuity, reading performance, facial recognition, and more. While the studies were generally found to have a moderate risk of bias, a GRADE assessment of the evidence suggests that the general certainty of the evidence was low-moderate.Conclusions: A positive effect of low vision devices was found for visual acuity, reading performance, facial recognition, and more. Simple low vision devices (e.g. magnifiers) appear to currently have greater preferential support than newer, visual enhancement technology (e.g. head mounted devices). Factors influencing this were discussed relative to low vision device features, the AMD demographic, and financial considerations. This is compounded by a lack of studies examining newer technologies in AMD populations, which future research should address. Moreover, given the presence of bias across the studies, heighted by limited controlled experiments, there may be inadequate confidence in the results. So, even though low vision devices are reported to be a valuable asset to AMD populations, more rigorous research is required to draw conclusive evidence.

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