Relationship between visual span and reading performance in age-related macular degeneration

PURPOSE: Visual-span profiles are plots of letter-recognition accuracy as a function of letter position left and right of the point of fixation. Legge, Mansfield, and Chung [Legge, G. E., Mansfield, J. S., & Chung, S. T. L. (2001). Psychophysics of reading-XX. Linking letter recognition to reading speed in central and peripheral vision. Vision Research, 41(6), 725-743] proposed that reduced size of the visual span is a spatial factor limiting reading speed in patients with age-related macular degeneration (AMD). We have recently shown that a temporal property of letter recognition--the exposure time required for a high level of accuracy--is also a factor limiting reading speed in AMD [Cheong, A. M. Y., Legge, G. E., Lawrence, M. G., Cheung, S. H., & Ruff, M. (2007). Relationship between slow visual processing and reading speed in people with macular degeneration. Vision Research, 47, 2943-2965]. We measured the visual-span profiles of AMD subjects and assessed the relationship of the spatial and temporal properties of these profiles to reading speed. METHODS: Thirteen AMD subjects and 11 age-matched normals were tested. Visual-span profiles were measured by using the trigram letter-recognition method described by Legge et al. (2001). Each individual's temporal threshold for letter recognition (80% accuracy criterion) was used as the exposure time for measuring the visual-span profile. Size of the visual span was computed as the area under the profile in bits of information transmitted. The information transfer rate in bits per second was defined as the visual-span size in bits divided by the exposure time in sec. RESULTS: AMD visual-span sizes were substantially smaller (median of 23.9 bits) than normal visual-span sizes in central vision (median of 40.8 bits, p<.01). For the nine AMD subjects with eccentric fixation, the visual-span sizes (median of 20.6 bits) were also significantly smaller than visual spans of normal controls at 10 degrees below fixation in peripheral vision (median of 29.0 bits, p=.01). Information transfer rate for the AMD subjects (median of 29.5 bits/s) was significantly slower than that for the age-matched normals at both central and peripheral vision (median of 411.7 and 290.5 bits/s respectively, ps<.01). Information transfer rates were more strongly correlated with reading speed than the size of the visual span, and explained 36% of the variance in AMD reading speed. CONCLUSION: Both visual-span size and information transfer rate were significantly impaired in the AMD subjects compared with age-matched normals. Information transfer rate, representing the combined effects of a reduced visual span and slower temporal processing of letters, was a better predictor of reading speed in AMD subjects than was the size of the visual span.     

Impact of visual impairment on use of caregiving by individuals with age-related macular degeneration

BACKGROUND: To assess the patient-reported use of caregiving among individuals with age-related macular degeneration (AMD) and evaluate the impact of visual impairment level on this use. METHODS: A survey including the AMD Health and Impact Questionnaire and the Daily Living Tasks Dependent on Vision Questionnaire (DLTV) was mailed to members of the Macular Degeneration Partnership. The study was approved by an institutional review board, and respondents provided consent before participating. Responses were analyzed by estimated visual acuity determined by scores from the DLTV. Deidentified data were analyzed using SAS Version 8.2 (SAS Institute, Cary, NC). RESULTS: Of 803 respondents, 56% were male, and the mean age was 73 years. Use of paid and unpaid help significantly increased as visual acuity decreased. Using a national average for caregiver time, annual costs for caregiving ranged from 225 to 47,086 US dollar depending on visual acuity. CONCLUSION: There are substantial differences in caregiver support with increased AMD severity. Delaying progression of AMD could result in considerable cost savings.     

年龄相关性黄斑变性视力损害及康复的研究现状

年龄相关性黄斑变性（AMD）是老年人视力丧失的主要原因,分为干性AMD和湿性AMD两大类,干性AMD可以转化为湿性AMD导致视力进一步损害。眼科医生除给予常规治疗外,还应根据患者视力损害的特点加以个性化康复,通过寻找训练优选的视网膜定位点、合理利用各种助视器、恰当的医患沟通、必要的人文关怀及随访来达到有效的视功能康复。     

白内障手术对年龄相关性黄斑变性的影响

年龄相关性白内障和年龄相关性黄斑变性(age-related macular degeneration,AMD)是导致老年人视力损害的重要眼病,而老年人常会同时患这两种年龄相关性眼病.早期研究认为白内障术后可促进AMD的进展.但随着对疾病的认识逐渐加深以及治疗策略的不断进步,白内障手术是否对AMD有较大影响尚存争议.本文将对两种疾病的发病率、白内障手术治疗与AMD进展的关系,以及如何在白内障手术后有效降低AMD的手术风险进行综述.     

老年性黄斑变性玻璃体积血的玻璃体手术治疗

目的探讨老年性黄斑变性(AM D)伴玻璃体积血的诊断,观察单纯玻璃体切割治疗玻璃体积血对AM D的治疗效果。方法回顾分析10例渗出型AM D并发大量玻璃体积血住院行玻璃体切割手术治疗患者的临床资料。患者平均年龄63岁。3例患者患眼或对侧眼曾有黄斑玻璃疣或黄斑出血。9例患者视力为光感或手动。结果10例患者B型超声检查除玻璃体内光点外,后极眼底前都见到一条光带,光带下有点状高回声;4例患者同时在下方探查到有高回声的局限性视网膜隆起。手术中发现视网膜及视网膜色素上皮下大片出血,范围占1/2至4/5眼底,出血量大时可隆起。5例患者黄斑区见到黄色扁平、拟为新生血管膜的病变。手术仅作玻璃体切割。手术后随访时视网膜下出血吸收,原拟为新生血管膜的病变成为黄白色瘢痕。视力数指~0.3。无一例再发出血。结论渗出型AM D并发玻璃体积血患者B型超声显示后极或下方的视网膜脱离光带伴高回声光点为其特征性改变,单纯玻璃体手术可提高患眼视力。新生血管膜在大量出血后形成瘢痕,病情转向稳定。     

Measurement of the economic impact of visual impairment from age-related macular degeneration in Australia

The purpose of this report was to: (i) outline the potential value of health economic studies into age-related macular degeneration (AMD); (ii) provide an overview of health economic studies pertinent to AMD; and (iii) outline the basic frame work of cost-of-illness studies (a useful first step in applying economic methods). The detection and management of sensory loss in the elderly plays a key role in the Australian Government's Healthy Ageing Strategy. Age-related macular degeneration is currently the leading cause of blindness in elderly Australians. Although a large proportion of AMD cases remain untreatable, the introduction of photo-dynamic therapy provides a relatively expensive and possibly cost-effective innovation for others. Antioxidant therapy has also been proven effective in reducing progression of early to late disease. The discipline of economics can contribute to an understanding of AMD prevention and treatment through: (i) describing the current burden of disease; (ii) predicting the changes in the burden of disease over time, and (iii) evaluating the efficiency of different interventions. Cost-of-illness studies have been performed in many fields of medicine. Little work, however, has been done on describing the economic impact from AMD. A number of different economic evaluation methods can be used in judging the efficiency of possible interventions to reduce the disease burden of AMD. Although complementary in nature, each has specific uses and limitations. Studies of the economic impact of eye diseases are both feasible and necessary for informed health care decision-making.     

雷珠单抗治疗重度视力损害渗出型年龄相关性黄斑变性患者的疗效观察

目的观察玻璃体腔注射雷珠单抗治疗重度视力损害渗出型年龄相关性黄斑变性(AMD)患者的疗效。方法回顾性分析在我院确诊为渗出型AMD、最佳矫正视力(BCVA)<0.05并接受雷珠单抗玻璃体腔注射的46例患者(47只眼)的临床资料。所有患者均行玻璃体腔注射雷珠单抗治疗,治疗后随访1~8个月,平均随访(4.09±2.25)个月。对比分析玻璃体腔注射雷珠单抗治疗前后BCVA、黄斑中心视网膜厚度(CRT)、病变最厚处视网膜厚度(MRT)的变化及不良反应的发生情况。结果至末次随访时,47只眼中,视力提高29只眼,占61.7%;视力稳定15只眼,占31.9%;视力下降3只眼,占6.4%。治疗后,平均CRT由治疗前的(301.30±84.57)μm降低为(211.27±87.03)μm;与治疗前相比,平均CRT下降(90.03±33.99)μm,差异有统计学意义(t=4.336,P<0.01);MRT由(529.04±174.63)μm降低为(421.86±95.78)μm;与治疗前相比,平均MRT下降(107.17±42.46)μm,差异有统计学意义(t=3.984,P<0.01)。结论雷珠单抗治疗重度视力损害渗出型AMD患者具有较好的疗效。     

玻璃体腔内注射Bevacizumab联合白内障手术治疗湿性年龄相关性黄斑变性(英文)

目的:探讨玻璃体腔内注射bevacizumab (Avastin)联合白内障手术预防脉络膜新生血管(choroidal neovascularization,CNV)的再次激活及年龄相关性黄斑变性(age-relatedmacular degeneration, AMD)。方法:对12例接受湿性年龄相关变性治疗的白内障患者给予透明角膜切口白内障超声乳化和人工晶状体植入手术,最后予以玻璃体腔内注射1.25mg bevacizumab (0.05mL)。主要评价指标:视力恢复、脉络膜新生血管的再次激活,及相干光断层成相术(OCT)对渗漏液体的评估。结果:患者最佳矫正视力(best-corrected visual acuity, BCVA)术后显著提高(脉络膜新生血管闭合后P<0.01,白内障发生后P=0.049,t检验)。白内障术后平均随访时间为11.8mo(标准差6.1,范围3 ～22mo),随访期内患者未出现脉络膜新生血管的再次激活及新的脉络膜新生血管病变。结论:在给予脉络膜新生血管及年龄相关性黄斑变性治疗的患者,白内障手术联合玻璃体腔内注射bevacizumab可预防脉络膜新生血管的再次激活。     

Therapeutic approach in patients with age-related macular degeneration and cataract

Management of the patient with coexisting cataract and AMD presents unique challenges to the cataract surgeon, the retina specialist, and the patient. A common clinical scenario is the patient in whom both the cataract and macular pathology appear to be contributing to decreased visual acuity. As with any surgery, the expectations from cataract removal must be evaluated thoroughly and understood clearly by both the patient and the cataract surgeon. Most patients with AMD who undergo cataract surgery feel that the surgery is worthwhile, and they report improvement of visual function and quality of life. In patients with mild AMD, improvement in central visual acuity and attainment of driving vision are realistic and achievable goals. In an eye with central disciform scarring or geographic atrophy there may be potential for improvement in color discrimination, contrast, or clarity of peripheral vision. In cases of dense cataract obscuring macular detail, cataract removal may be necessary to allow for adequate biomicroscopy and angiography, especially in an eye that may be at high risk for the development of choroidal neovascularization. It is often challenging to estimate the relative impact on visual impairment made by the lens opacities and the macular changes and the benefits and risks of cataract surgery in eyes with AMD should be carefully evaluated. Is cataract surgery justified in these patients? Does cataract surgery aggravate AMD in some patients?     

年龄相关黄斑变性白内障患者超声乳化人工晶状体植入术后疗效分析

目的:探讨白内障手术对伴有年龄相关黄斑变性(agerelated macular degeneration,AMD)的白内障患者的治疗效果,评价手术的价值。方法:对31例37眼同时伴有AMD的白内障患者行超声乳化人工晶状体植入术,术后随访3～6mo,分析其临床效果。结果:术后所有患者的视力均有不同程度的提高,其中指数2眼(5%),0.01～0.08者11眼(30%),0.1～0.2者12眼(32%),0.3者8眼(22%),0.4～0.5者4眼(11%);术后有1眼(3%)AMD病变加重,为湿性AMD。结论:对于同时伴有AMD的白内障患者,综合考虑其黄斑和晶状体情况,在白内障严重影响视力的情况下,为了提高患者的生活质量,应该积极地进行白内障手术。     

Rehabilitation of reading skills in patients with age-related macular degeneration

Reading is the most frequent clinical complaint and the primary goal for patients with macular degeneration seeking vision rehabilitation. The current prevalent methods for reading skills training across the globe are still magnification and basic scotoma awareness training. More recent studies showed that specific eccentric training, comprehension ability training, and specific oculomotor training are all beneficial to reading skills rehabilitation. In clinical practice, ophthalmologists should strive to implement reading skills methods that include assessment of cognitive skills, optimal eyewear, optimal reading material, PRL assessment, training of better oculomotor control, and efficient perceptual training.     

年龄相关性黄斑变性合并白内障手术治疗的研究进展

年龄相关性黄斑变性(age-related macular degeneration, AMD)与白内障是世界范围内最常见的导致低视力的疾病.目前对于合并AMD的白内障患者是否应该实施手术和手术的时机问题尚存争议.本综述的目的在于评估白内障手术对于AMD发生和发展的影响,分析其影响因素,探讨合并AMD的白内障手术时机和联合抗VEGF等治疗,还包括人工晶状体的研究进展和应用,以期选择综合治疗措施,避免和减缓白内障手术后黄斑变性的发生和发展,以保证患者获得良好的视力转归.     

Repeatability of visual function measures in age-related macular degeneration

Purpose

To assess repeatability of visual function measures in patients with early, intermediate or late age-related macular degeneration (AMD) without active neovascular disease in the study eye, but active neovascular AMD in the fellow eye.

Methods

One hundred subjects from an ongoing trial were screened for this study in which their LogMAR acuity, contrast sensitivity and reading performance were assessed using standardised protocols by trained optometrists. The same measures were repeated one month later and repeatability of the visual functions assessed.

Results

Data from 83 subjects satisfied inclusion criteria for analysis. Coefficient of repeatability was 14.9 letters for LogMAR visual acuity , 7.2 letters for Pelli Robson contrast sensitivity, 0.72 for LogMAR reading acuity, 110.4 words/ min for reading speed and 0.67 for LogMAR critical print size. Intraclass correlation coefficients allowed comparison between measures and were found to be 0.96 for LogMAR visual acuity, 0.93 for contrast sensitivity, 0.75 for LogMAR reading acuity, 0.79 for reading speed and 0.74 for LogMAR critical print size. Coefficients of variation were 9.4 %, 10.7 %, 48.4 %, 28.4 % and 31.8 % respectively.

Conclusions

We found coefficients of repeatability that concurred with previous studies demonstrating variability of visual functions in patients with AMD. In addition, we found intraclass correlation coefficients to be better with visual acuity and contrast sensitivity than with measures of reading performance.     

Computer-based test to measure optimal visual acuity in age-related macular degeneration

PURPOSE: The authors present a computer-based method for evaluating the visual acuity of patients with age-related macular degeneration (AMD). It incorporates four features known to improve visual acuity: high contrast, white optotypes on a black background to reduce intraocular scatter, proportional layout to reduce the effects of crowding, and multiple optotypes to minimize the effects of fixation instability and to maximize the likelihood of optotype detection. METHODS: Experiment 1 evaluated the best-eye acuity of 24 patients with AMD using the ETDRS chart and three versions of the Tumbling E acuity test: multiple black optotypes on a white background, single white optotype on a black background, and multiple white optotypes on a black background. Experiment 2 compared the two White E optotype tests with the ETDRS in patients with AMD, and Experiment 3 measured probability summation in persons with normal vision. RESULTS: Multiple white optotypes on a black background yielded the highest acuity estimates and the ETDRS the lowest. The Single E test yielded a lower estimate of acuity than the two Multiple E tests. The effect of polarity-white on black was better than black on white-was consistent with results found in persons with healthy retinas. For patients with AMD, acuity measured with the Multiple E test was independent of that measured with the ETDRS, but acuity measured with the Single E test decreased as acuity worsened. For the participants with normal vision, the differences between the Multiple and Single E tests were within the known limits of test-retest variability. CONCLUSIONS: The multiple-optotype, reversed-polarity test provides a measure of the optimal visual acuity of which a person is capable and, in this sense, may be a useful tool for assessing rehabilitation progress.     

Visual outcomes following cataract surgery in age-related macular degeneration patients

ObjectiveTo evaluate visual acuity (VA) outcomes, prognostic factors, and changes in disease severity in patients with age-related macular degeneration (AMD) undergoing cataract surgery.DesignRetrospective cohort studyParticipantsPatients with AMD or healthy control patients who underwent cataract surgery between 2012 and 2017.MethodsEyes were categorized into 3 AMD groups—intermediate AMD (iAMD), fovea-involving geographic atrophy (GA), neovascular AMD (nAMD)—and 3 preoperative VA-matched control groups (iAMDc), fovea-involving geographic atrophy control (GAc), neovaascular AMD control (nAMDc).ResultsWe compared 216 iAMD, 35 GA, and 184 nAMD eyes with 130, 31, and 129 controls. At postoperative month 12 (POM12), VA increased significantly in iAMD and nAMD (+10.1 ± 14.5 and +9.7 ± 18.9 letters, p < 0.001), but not in GA (p = 0.68). All control groups showed significant VA gains (iAMDc: +17.1 ± 9.7, GAc: +30 ± 12.9, and nAMDc: +26.4 ± 15.6 letters, p < 0.001). For AMD groups, POM12 VA and gain in VA were significantly lower than that of controls (p < 0.01), and better preoperative VA predicted smaller VA gains (p ≤ 0.007). Longer duration of AMD in iAMD, ellipsoid zone disruption in nAMD, and lower central subfield thickness in GA were associated with poorer VA outcomes (p < 0.05). Development of nAMD occurred in 8 iAMD eyes and was associated with longer duration of disease (p = 0.001). For nAMD eyes, injection frequency did not vary between the 12-month pre- and postoperative periods (p = 0.051).ConclusionsCataract surgery improves VA for patients with iAMD and nAMD, albeit not to the level of those without retinal pathology. Preoperative VA, AMD duration, and optical coherence tomography parameters may be important prognostic factors for cataract surgery in patients with AMD.     

Combined cataract surgery and vitrectomy for vitreous haemorrhage secondary to age-related macular degeneration

Purpose: To report on the functional outcome of surgery on patients with concurrent cataract and breakthrough vitreous haemorrhage from age‐related macular degeneration (ARMD). Methods: Retrospective case series. Results: Five eyes were included in the study. The post operative follow‐up interval ranged from 9 to 12 months. Preoperative visual acuity ranged from hand motion to perception of light. Two surgeries were complicated by iatrogenic breaks, and a further surgery was required to re‐attach the retina in one of these eyes. Only one of the five eyes experienced an improvement in visual functioning. Conclusion: In this series, the outcome of surgery for combined cataract and breakthrough vitreous haemorrhage, secondary to ARMD was poor. The functional outcome of surgery for combined cataract and vitreous haemorrhage secondary to ARMD in this series was poor.