Rehabilitation of the visually handicapped with advanced macular degeneration

Hundred-and-twenty patients with advanced macular degeneration (senile, disciform, and hereditary forms), which could not be helped in a satisfactory way by simple magnifying aids, were studied for an average of 5 years (a minimum of 3 years), during which they had access to a full range of low vision rehabilitation measures including advanced optical aids and educational methods for training in the use of these aids and in the utilization of residual vision. The mean age of the patients was 72 years. They were all in a mental condition enabling them to understand and follow instructions. Just over half the patients were obliged to learn from the outset how to utilize peripheral retina, i.e. through eccentric viewing, high magnification low vision aids and very short reading distances, a mean of 4.4 cm, which demand specially qualified educational methods for low vision training. (A second group of 198 patients with macular degeneration was handled by the optician alone because either macular degeneration was moderate and the patients could manage with simple optical aids, or the patients were in such a bad mental condition, obvious already from the referral documents, that they were unable to use sophisticated aids in spite of the fact that they would have needed them with regard to their poor vision.)Telescopes were the most frequent aid used for distance, having a mean magnification of 4.6 X. Among the aids for reading, the most common were increased near additions and hyperocular lenses, having a mean power of 22.6 dioptres (magnification 5.7 X). Aids were also furnished for intermediate distance and for spot use. The mean number of series of visits was 2.5 and the number of training sessions (1 h) per series of visits was 3.0.Mean visual acuity improved from 0.18 to 0.64 with aids and training on the first series of visits, and reached 0.53 by the last series. The number of patients able to read TV titles increased from 6.7% to 57.5% and was 49.2% after the last series of visits. The number of individuals able to read newspaper text increased from 0.8% to 92.5%. After the last series of visits, the number was still as high as 80.0%.The results show that the presented methods for rehabilitation of patients with macular degeneration through optical aids and educational methods for training in the utilization of these aids and of residual vision are outstandingly successful. The use of the individual's vision and his situation in life often improve dramatically. In addition, costs for other forms of social aid are reduced or even eliminated.     

Determining magnification for reading with low vision

Background : In the past, practitioners have used distance and/or near visual acuity (VA) to calculate required magnification for low vision aids. Magnification was usually under‐estimated when compared with the final magnification prescribed. Recent studies have emphasised the importance of acuity reserve in determining the required magnification for optimum reading rate. Two different approaches have been proposed for the appropriate acuity reserve to use in calculating magnification. These are a fixed acuity reserve of 0.3 log unit or an individual determination of optimum acuity reserve. The aim of this study was to investigate the magnification and reading rates with low vision aids selected by the two methods. Methods : Nineteen low vision subjects with age‐related macular degeneration (AMD) who were experienced magnifier‐users were recruited. Reading rates and near VA with low vision aids determined by the fixed and individual acuity reserve methods were compared with the same measures made with the subjects' own magnifiers. Results : There were no significant differences in reading rate and near VA measured with low vision aids selected by either the fixed or individual acuity reserve methods or the subjects' own magnifiers. Reading rate with low vision aids was not significantly different from reading rate for large print with conventional near additions. Thus, for experienced users, magnifiers do not cause reduced reading rate. Conclusions : The fixed acuity reserve method is simple to apply as only near VA and print size of the target reading task are required. For the individual acuity reserve method, reading rates at different print sizes need to be measured. We recommend the use of a fixed acuity reserve (0.3 log unit) for the calculation of required magnification for low vision patients. If near VA or reading rate are not satisfactory with the magnification calculated by this method, individual assessment of required acuity reserve is necessary.     

Low vision service delivery: an audit of newly developed outreach clinics in Northern Ireland.

Recent publications recommend that low vision services are multi-professional; easily accessible; freely available to all those with visual impairment; monitored by professional and patient groups, and responsive to user feedback. These standards were applied when developing low vision outreach services in Northern Ireland in 1999/2000. Results are reported of the complete clinical audit cycle, coupled with a patient satisfaction telephone questionnaire, which was used to evaluate the service. Of the 48 patients randomly selected from the list of clinic attendees, 28 (58%) were female, 27 (56%) over 80 years of age and 38 (78%) had a primary ocular diagnosis of age related macular degeneration (AMD). Of the 46 low vision aids issued at patients' first appointments, 30 (67%) were illuminated stand magnifiers and 29 (63%) had magnification levels of x5 or less. A total of 46 (96%) patients reported that they had benefited from low vision services.     

Improvement of reading speed after providing of low vision aids in patients with age‐related macular degeneration

Purpose: Age‐related macular degeneration (AMD) is the most common cause of severe visual impairment, including loss of reading ability, among elderly persons in developed countries. The aim of the present study was to evaluate reading ability before and after providing of appropriate low vision aids. Methods: Five hundred and thirty patients with different stages of AMD (age 82 ± 8 years) were included in this retrospective study. All patients underwent a standardized ophthalmological examination including evaluation of magnification requirement and careful providing of low vision aids. Before and after the provision of low vision aids, reading speed [words per minute (wpm)] was evaluated using standardized reading texts. Results: For the whole group, the average best‐corrected distance visual acuity of the better eye was 0.18 ± 0.15, with 69% of patients having visual acuity of 0.1 (20/200) or better. The mean magnification requirement was 7.4 ± 6.3‐fold (range 2–25). Visual rehabilitation was achieved with optical visual aids in 58% of patients, whereas 42% of patients needed electronically closed‐circuit TV systems. Mean reading speed was 20 ± 33 wpm before and increased significantly to 72 ± 35 (p < 0.0001) after the provision of low vision aids for the whole group. Between patients with visual acuity < 0.1 and patients with visual acuity of 0.1 or better, there are highly significant differences in reading speed before (0.4 ± 3.8 versus 20 ± 28 wpm, p ≤ 0.0001) and after providing of visual aids (40 ± 13 versus 84 ± 30 wpm, p ≤ 0.0001). Patients with severe visual impairment (visual acuity ≤ 0.1) showed significantly lower improvement of reading speed compared to patients with visual acuity of 0.1 or better following rehabilitation (p ≤ 0.0001). Before providing of low vision aids, only 16% of patients were able to read; in contrast, reading ability was achieved in 94% of patients after the provision of low vision aids for the whole group. Conclusion: Our results indicate the great value of low vision rehabilitation through adequate providing of vision aids for the improvement of reading ability, with a highly significant increase of reading speed without training of eccentric viewing in patients with retained central fixation. The prompt implementation of low vision aids in patients with macular degeneration will help them to maintain and regain their reading ability, which can lead to an increase in independence, communication, mental agility and quality of life.     

Ophthalmologische und soziale Rehabilitation sehbehinderter Patienten

BACKGROUND: In addition to medical care, the visual and social rehabilitation of low-vision patients is of increasing importance. The aim of our study was to evaluate the actual spectrum of patients concerning diagnoses and appropriate low-vision aids at a low-vision clinic. METHODS: In a retrospective study, the medical records of 4,711 patients treated at our low-vision clinic from January 1999 to December 2005 were reviewed and analyzed. The main outcome measurements were age, ophthalmologic diagnoses, magnification requirement, and prescribed low-vision aids, as well as social and professional rehabilitation measures. To evaluate the efficiency of visual rehabilitation, reading speed was measured in a subgroup of 930 patients before and after administration of low-vision aids. RESULTS: Age-related macular degeneration was, at 40%, the most frequent diagnosis. Other main diagnoses were tapetoretinal dystrophies, optic atrophy, and diabetic retinopathy. The median magnification need was 4x. A highly significant correlation existed between the measured magnification power and the magnification factor of the prescribed low-vision aids. Visual rehabilitation was frequently sufficient with simple optical low-vision aids such as high-plus reading additions and magnifiers. Closed-circuit television systems were necessary in 26%; however, 85% of these patients had a high magnification need of more than 6 x. For distance vision, a monocular telescope was the low-vision aid prescribed most often. A high proportion of patients needed more than two low-vision aids for different application areas. Forty percent of patients needed special social and professional rehabilitation measures. In a subgroup of 930 patients, the mean reading speed was 35+/-50 words/min before the use of low-vision aids, which increased significantly to 81+/-46 words/min with the use of such aids. Therefore, the reading speed essentially doubled following the use of low-vision aids. CONCLUSION: Our results provide actual, quantitative data about the need for and success of rehabilitation for visually impaired patients. A large number of patients suffer from age-related macular degeneration. Independent from the causal ophthalmologic diagnoses, most patients benefited greatly from the rehabilitation measures provided by the low-vision service and were thus able to improve their quality of life. In the face of the increasing number of visually impaired elderly patients, rehabilitation should start as early as possible.     

The experience of a university-based low vision clinic

An open low vision clinic has been in operation at University of Wales College of Cardiff, Department of Optometry for 5 years. This paper describes the demography and visual characteristics of 218 consecutively presenting patients. A detailed survey of the aids prescribed is conducted. A significant proportion of low vision patients required only simple aids (56.8%) and low magnification (71.6%). It is suggested that these patients could be assisted in an optometric practice. In addition, visual acuity, distance or near is not a good indicator of eventual visual performance with an LVA. Therefore, it was concluded that all patients having measurable form vision should receive a low vision assessment.     

Ophthalmological rehabilitation – experience at the University Eye Hospital Heidelberg

BACKGROUND: The rehabilitation of low vision patients is of increasing importance since the number of these patients has grown rapidly. We wanted to evaluate the actual spectrum of patients concerning age and diagnoses and the appropriate low vision aids (LVA) in 1 year. METHODS: The records of the patients seen in our low-vision unit in 1996 were retrospectively evaluated. We correlated visual function, ophthalmological diagnoses and age to the magnification needed for rehabilitation and the use or prescribed LVAs. RESULTS: There was a nearly homogeneous distribution concerning age with a range from 0 to 99 years. Most patients presented with age-related macular degeneration (25.6 %) while 10 % each had retinitis pigmentosa and optic atrophy. Simple low vision aids such as high plus reading additions (29 %) and magnifiers (18.5 %) were prescribed in the majority of patients. However, closed-circuit TV (CCTV) systems were necessary in 25 %. CONCLUSIONS: Rehabilitation of low vision patients is often possible with simple LVAs. This is especially true for patients suffering from age-related macular degeneration. Since there is a tremendous-amount of different diseases, adequate diagnostic and individual counseling is of major importance.     

Primary success with low vision aids in age-related macular degeneration.

The benefit obtained from various low vision aids (LVAs) was studied in 65 consecutive patients with atrophic (70.3%) or disciform (29.7%) age-related macular degeneration (ARMD). 13.8% were able to read newsprint with age-related reading correction under proper lighting conditions. The primary success achieved with LVAs was good, 91.4% of patients being able to read newsprint. In most cases a simple magnifier (52.3%), high-powered reading glasses (10.8%) or Fonda's glasses (12.8%) were sufficient. The magnification preferred was 5x or less in 25.6% and greater than 5x to 9x in 48.8%. Patients with disciform degeneration required higher magnification than those with atrophic degeneration. It is concluded that most patients with ARMD found low vision aids useful for reading purposes and that a simple optical device was sufficient to achieve reading vision.     

Low vision aids for reading in scar stage of age-related macular degeneration

PURPOSE: To evaluate the inter-relationship among near visual acuity, eccentricity of preferred retinal locus(PRL), and choice of low vision aids for reading in patients with bilateral age-related macular degeneration(AMD). SUBJECTS AND METHODS: The preferred eye of 44 patients having bilateral disciform stage AMD was examined. The PRL was detected and its eccentricity from the fovea was measured by scanning laser ophthalmoscopic microperimetry. Magnification of a low vision aid for reading newsprint was determined by the critical print size which was calculated using the MNREAD-J. The type of preferred aid was chosen from high-plus lens glasses, magnifiers, and closed-circuit televisions. The inter-relationship among near visual acuity, eccentricity of the PRL, and magnification and type of low vision aid for reading were evaluated. RESULTS: The magnification of the aid was correlated with the eccentricity of PRL in eyes with near visual acuity of 0.2 or less although no correlation was found in eyes with near visual acuity better than 0.3. High plus lens glasses were selected by patients with near visual acuity better than 0.2 and eccentricity of 2 degrees or less. Magnifiers were selected by patients with near visual acuity better than 0.1 and eccentricity of 5 degrees or less. Closed-circuit televisions were selected by patients with near visual acuity of 0.1 or less and eccentricity of 5 degrees or more. CONCLUSION: The eccentricity of PRL should be taken into account in determining low vision aids for reading, especially in patients with near visual acuity of 0.2 or less. Choice of the type of low vision aid depends on not only near visual acuity but also on eccentricity of PRL.     

原发性青光眼患者术后低视力及康复效果观察

目的 :了解原发性青光眼术后低视力患者远近矫正视力及应用助视器后的矫正视力 ,研究针对造成低视力的相关因素所进行康复治疗的效果。方法 :对 10 4例原发性青光眼患者 16 5只眼术后近期 (第 4周 )裸眼及矫正远近视力进行分析 ,分析导致低视力的病因 ,并观察给予相应助视器矫正后的视力康复情况。结果 :16 5眼中有 38眼为低视力 ,主要病因为青光眼性视神经萎缩、眼底病变、并发性白内障、角膜病变等。应用助视镜后 ,76 .3%的低视力眼的矫正远视力和 84.2 %的矫正近视力可提高到有用视力。结论 :助视镜的应用仍是较为可靠、有效的康复治疗方法之一 ,但仍需改进     

Recent experiences in the management of visual impairment in albinism

One hundred patients with albinism seen within two years in the Low Vision Clinic at Moorfields Eye Hospital are reviewed. They are predominantly young people within the definition of 'Partially-sighted' rather than blind. Clinical methods are described and the distribution of alternative types of appliance loaned surveyed. Emmetropia and low ametropia are rare in the group. Most patients are using telescopic lenses for distance vision, tending to select binocular devices. Over half are able to read print of newsprint size in a clinical situation without extra magnification, but often elect to use extra magnification for some tasks. The need for near vision aids increases with age.     

Clinical effect of low vision aids

The number of patients with low vision is increasing as life expectancy increases. In addition, the interest and demand for low vision aids are also increasing with improved socioeconomic status and the development of mass media. Therefore, it is imperative to recognize the importance of low vision aids. We reviewed the clinical records of 118 patients who visited our low vision clinic more than twice. According to the data analyzed, optic nerve atrophy, retinal degeneration, diabetic retinopathy and age-related macular degeneration were the most common causes of low vision in these patients. The best corrected visual acuities without low vision aids were less than 0.3, but with the help of low vision aids, vision improved to more than 0.4 in 87% of the patients for near vision, and 56% for distant vision. The patients had complained that they could not read books, see a blackboard, recognize a person at a distance, and had other problems because of low vision. However, with the use of low vision aids their satisfaction with their vision rose to 70%. Hand magnifiers, high-powered spectacle lenses, and stand magnifiers were the low vision aids commonly used by people for near vision, while the Galilean telescope and Keplerian telescope were the most popular devices used for distant vision. In conclusion, low vision aids are very helpful devices to patients with low vision.     

The changing face of the visually impaired: the Kooyong low vision clinic's past, present, and future.

PURPOSE: To demonstrate the changes that have occurred in a developed world low vision population over the past three decades and to examine the present rehabilitation of the visually impaired attending a multi-disciplinary low vision clinic. METHODS: A retrospective examination of the 22,860 patients attending the low vision clinic at Kooyong since its inauguration in 1972 to 1996 allowed the extraction of information on their age, gender, living status, and primary condition causing low vision. A prospective unified study of 590 patients attending the clinic over a 6-month period in 1998 examined the demographics of the present low vision population and what rehabilitation they received. RESULTS: The average age of patients attending the low vision clinic has steadily increased, with 87% over the age of 60 years in the mid-1990s compared to 71% in the mid-1970s. The percentage of female patients attending the clinic has also steadily risen over the past three decades (from 59 to 66%), as has the percentage of patients living alone (from 23 to 41%). The main change in the conditions causing visual impairment in the clinic's low vision population has been the increase in age-related macular degeneration (ARMD). The average presenting distance acuity was 6/38, improving to 6/30(-1) with refraction. One-third of the patients could manage N5 print with the aid of +4.00 near addition lenses or less. Over one-half were prescribed magnification aids, with 19% having need for 2 or more to accomplish their desired visual tasks. Two-thirds of the patients made use of staff from multiple disciplines during their visual rehabilitation. CONCLUSIONS: The low vision population has changed over the past three decades. Major changes that have implications on low vision rehabilitation services are the increasing age of the patients and the preponderance of ARMD.     

Clinical study of low vision. Part I: Refraction and the aided distance vision

Eighty three cases of low vision patients (144 eyes) were examined with distant visual aids. The average visual acuity of the 144 eyes before refraction was approximately 0.07, while the counterpart afterwards was about 0.1 (p less than 0.01). With the 4x monocular focusable aid, acuity improved in 142 eyes out of the 144 eyes. The combined use of clip-on distance aid and the spectacle reading aid was observed to be especially suitable for partially sighted students. The mean MEF of 142 eyes was 0.9435 +/- 0.2068. The paired T-test between the difference of actual magnification and theoretical magnification was not significant at the 5% level. The factors contributing to the variance of MEF were discussed.     

Age-related macula degeneration and diabetic retinopathy -- differences in optic rehabilitation

BACKGROUND: Age-related macular degeneration (AMD) and diabetes mellitus are the major contributing causes of visual impairment in the industrial nations. This study shows how far visual acuity (VA) and magnification demand (MD) influence the selection of suitable low vision aids. Based on this information, differences regarding the spectrum of prescribed magnifying devices between both patient groups will be presented. MATERIALS AND METHODS: Between January 2003 and October 2004, a total of 2500 patients was seen in our Low Vision Department. Among them were 1198 patients with AMD (48 %) and 296 visually impaired patients because of diabetic ocular involvement (12 %). In every patient, best corrected distance and near VA as well as the required MD were measured. Finally, matching of magnifying aids and discussing aspects of professional and social rehabilitation were the main parts of our interdisciplinary Low Vision Service. RESULTS: In AMD patients, the average of best corrected distance VA at the better eye was 0.24, the best corrected near VA was 0.19. In diabetes patients, the average of best corrected distance VA at the better eye was 0.28, the best corrected near VA was 0.22. The required mean MD was 4.0 x (related to the reading of newspaper text) compared to 7.6 x in patients with AMD. In 94 % of the visually impaired diabetes patients, optical magnifiers could be prescribed (e. g. magnifying eyeglasses, telescopes, monoculars, Galelean and Keplerian systems), whereas electronic devices were necessary in only 6 %. In comparison, 14.8 % of the patients with AMD had to be provided with electronic systems. CONCLUSIONS: In 94 % of the visually impaired patients caused by diabetes, reading ability could be restored using optical low vision aids. In AMD patients, this could be achieved in only 85.2 %. This fact can mainly be explained with the negative effect of absolute central scotomas on reading speed in AMD patients which leads, compared to diabetes patients, to elevated magnification factors. Therefore, the choice of certain magnifying devices depends not only on VA, but has mainly to be evaluated based on the individual MD.     

Age-related macular degeneration and its management

Age-related macular degeneration is a major cause of vision loss in older individuals. The clinical picture and pathogenesis of age-related macular degeneration is reviewed. Present treatment modalities for subretinal vascularization in exudative-type macular degeneration and their limitations are discussed. The role of low-vision aids in providing magnification for reading vision is described. The role of intraocular lens implantation is discussed, as well as the newly developed intraocular lens which, with the addition of a plus-lens, functions as a Galilean telescope to provide magnification for near vision.     

Predicting prescribed magnification.

AIM: To determine the best method of estimating the optimum magnification needed by visually impaired patients. METHODS: The magnification of low vision aids prescribed to 187 presbyopic visually impaired patients for reading newspapers or books was compared with logMAR distance and near acuity (at 25 cm) and magnification predicted by +4 D step near additions. RESULTS: Distance letter (r = 0.58) and near word visual acuity (r = 0.67) were strongly correlated to the prescribed magnification as were predictive formulae based on these measures. Prediction using the effect of proximal magnification resulted in a similar correlation (r = 0.67) and prediction was poorer in those who did not benefit from proximal magnification. The difference between prescribed and predicted magnification was found to be unrelated to the condition causing visual impairment (F = 2.57, p = 0.08), the central visual field status (F = 0.57, p = 0.57) and patient psychology (F = 0.44, p = 0.51), but was higher in those prescribed stand magnifiers than high near additions (F = 5.99, p < 0.01). CONCLUSIONS: The magnification necessary to perform normal visual tasks can be predicted in the majority of cases using visual acuity measures, although measuring the effect of proximal magnification demonstrates the effect of stronger glasses and identifies those in whom prescribed magnification is more difficult to predict.     

新型近用连续变焦电子助视器在低视力和盲康复中的应用

目的比较新型近用连续变焦电子助视器和近用光学助视器在低视力和盲康复中的有效性。方法前瞻性病例对照研究。19例低视力患者和14例盲患者分别使用近用光学助视器和近用连续变焦电子助视器阅读报纸里的新闻文章,记录使用2种仪器后的近视力、阅读速度和阅读持续时间,采用配对t检验对检查结果进行统计学分析。结果所有患者使用近用光学助视器和近用连续变焦电子助视器后近视力相比,差异有统计学意义（t=-2.392,P＜0.05）;盲患者和低视力患者分别使用2种助视器后近视力比较,差异有显著统计学意义（t=-7.433、-8.721,P＜0.01）。所有患者和盲患者使用近用光学助视器和近用连续变焦电子助视器后阅读速度相比,差异有显著的统计学意义（t=-4.290、-6.728,P＜0.01）;低视力患者分别使用2种助视器后阅读速度比较,差异无统计学意义（t=-1.534,P＞0.05）。所有患者、盲患者以及低视力患者分别使用近用光学助视器和近用连续变焦电子助视器后阅读持续时间相比,差异有显著统计学意义（t=-8.211、-6.137、-6.007,P＜0.01）。结论新型近用连续变焦电子助视器与传统的近用光学助视器相比,更能提高患者的近视力和改善阅读能力。     

远用光学助视器在视力残疾患者康复中的临床应用

目的:观察远用助视器在视力残疾患者的临床应用效果。方法:对32例视力残疾患者进行屈光矫正后,然后再运用单筒望远镜式助视器或眼镜式助视器提高和改善患者远用视力。结果:配用远用助视器平均视力(logMAR视力)为0.24±0.23;而在屈光矫正的基础上再应用助视器矫正的患者平均视力(logMAR视力)为0.11±0.25,即戴镜后使用远用助视器后视力好于未戴镜患者(t=4.56,P<0.05)。试戴远用助视器后25例远视力≥0.3,脱残率为78%;进行屈光矫正后,该组病例脱残率为94%(P<0.05)。结论:远用光学助视器在视力残疾患者康复有着重要作用,它可提高患者的远用视力,尤其强调在屈光矫正的基础上应用光学助视器临床疗效更为明显。