|Year : 2020 | Volume
| Issue : 4 | Page : 261-267
Eccentric viewing training for low-vision rehabilitation in patients with central scotoma
Adel G Zaky1, Boshra El Bayoumi2, Esraa S El-ghoubashy1, Abdelrahman E Sarhan1, Marwa A Zaky1
1 Department of Ophthalmology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Memorial Institute of Ophthalmology, Giza, Egypt
|Date of Submission||31-Mar-2020|
|Date of Decision||14-May-2020|
|Date of Acceptance||08-Jun-2020|
|Date of Web Publication||28-Dec-2020|
MS Esraa S El-ghoubashy
Department of Ophthalmology, Faculty of Medicine, Menoufia University, Menoufia 32511
Source of Support: None, Conflict of Interest: None
Background Eccentric viewing (EV), also known as eccentric fixation, involves identifying a functioning area of the retina that is as close to the fovea as possible and to learn to use it effectively, which is known as the preferred retinal locus.
Objective The aim of this study was to evaluate the value of subjective EV training in vision rehabilitation in patients with central scotoma.
Patients and methods The direction of EV was monitored in 33 low-vision patients with bilateral central scotomas. The preferred retinal locus was identified, and the preserved visual field was found. The patients were divided randomly into two groups regarding their use of optical low-vision devices with EV training. After 2 months of training, changes in near and far best-corrected visual acuity (BCVA) and reading speed were evaluated.
Results After 2 months of EV training, the near BCVA and mean reading speed significantly improved, whereas the far BCVA did not significantly improve (0.1 LogMar on average). The mean near BCVA improved from 0.97±0.19 to 0.63±0.26 LogMar (P<0.001), and the mean reading speed improved from 26.48±9.31 words per minute (wpm) to 53.82±10.81 wpm. The group that used low-vision devices with EV training showed significantly more improvement in near and far BCVA than the group that did not use low-vision devices. The group that used low-vision devices with EV training showed significantly more improvement in near BCVA (0.41±0.17 LogMar) than the group that did not use low-vision devices (0.78±0.28 LogMar, P<0.001). Moreover, the group that used low-vision devices with EV training showed significantly more improvement in far BCVA (0.75±0.17 LogMar) than the group that did not use low-vision devices (1.02±0.28 LogMar, P<0.001).
Conclusion EV training can be used as a very effective method for low-vision rehabilitation in patients presenting with central scotomas. It can give very good results by using simple and inexpensive equipment.
Keywords: central scotoma, eccentric viewing, low-vision rehabilitation, preferred retinal locus, reading speed
|How to cite this article:|
Zaky AG, Bayoumi BE, El-ghoubashy ES, Sarhan AE, Zaky MA. Eccentric viewing training for low-vision rehabilitation in patients with central scotoma. Delta J Ophthalmol 2020;21:261-7
|How to cite this URL:|
Zaky AG, Bayoumi BE, El-ghoubashy ES, Sarhan AE, Zaky MA. Eccentric viewing training for low-vision rehabilitation in patients with central scotoma. Delta J Ophthalmol [serial online] 2020 [cited 2022 Jan 28];21:261-7. Available from: http://www.djo.eg.net/text.asp?2020/21/4/261/304938
| Introduction|| |
Macular diseases usually result in what is known as central vision loss (CVL). The CVL impairs greatly the tasks of daily living such as driving, face recognition, object recognition, and reading . For normal individuals with a functioning fovea, the visual tasks are done by directing the eye such that the image of the visual target of regard is placed within the central foveal area . In contrast, in patients with a central scotoma from any macular disease involving all of the fovea, the visual tasks are performed by directing the eye such that the image of the target of regard is placed within an area of the retina that is functioning known as the preferred retinal locus (PRL) ,.
In patients with bilateral central vision impairment, restoration of vision by residual vision training can be a valuable resource that can help them to use the rest of their vision by eccentric viewing (EV) .
EV, also known as eccentric fixation, involves identifying an area of the retina that have reasonable sensitivity, and is as close to the fovea as possible in order to maximize details, and to learn to use it effectively, which is known as the PRL . Many portions of the peripheral retina may be suitable for EV, depending on task demands and the visual properties of the objects being viewed .
EV is usually established at an early age in patients with a congenital macular lesion. In contrast, in elderly patients, EV is rarely obtained spontaneously, as in younger age, and usually needs vision rehabilitation and a lot of training ,.
Steady eye strategy (SES) is a technique that specifically helps with reading. SES requires the patient to break the saccadic reflex by keeping their gaze still, and scrolling the text right to left, through their functional area of vision. As the text is moved in SES, the eye can be trained so that the letters fall on the predetermined PRL. Magnification may improve the ability to see the letters, but the patient may still not to be able to read successfully as there are now fewer letters on the PRL at any one time .
Many low-vision aids can be used for magnification, which may be optical and nonoptical devices. Optical devices may be for near or for distance vision. Near devices are designed for magnifying close objects and print such as magnifying glasses; magnifiers, which may be stand or hand held; and telescopes for near. Distance devices are for magnifying things in the distance (from about 3 m too far away), such as telescopes for far .
Nonoptical low-vision aids are products built to facilitate self-sufficient living. They alter the understanding of the world by being larger, brighter, and blacker, or by being coloring and contrasting. Thus, the purpose of a nonoptical system is to increase retinal image visibility and to maximize the use of magnifiers, such as reading lamp; reading stand; writing guide; reading guide; signature guide; bold line papers; black ink; bold tip pens; soft lead pencil 2B, 4B, and 6B; needle threaded; and reading guide .
There are several teaching methods for EV, the newest of which is scanning laser ophthalmoscope (SLO) and microperimeter. They have the advantage that the retinal image is rendered clear and thus the scotoma limits are seen and the PRL can be accurately calculated. Microperimeters are very expensive and often not available for vision rehabilitation, especially in developing countries. However, we agree that microperimetry is not necessary for learning to use EV effectively ,.
Many EV training methods, such as prismatic scanning or relocation, strips, and rotors with letters or numbers of various sizes and advanced training sheets, have been used .
However, EV training requires the presence of bilateral absolute central scotoma and the ability of the patient to comprehend and remember simple instructions .
The aim of this study was to evaluate the value of subjective EV training in vision rehabilitation in patients with central scotoma.
| Patients and methods|| |
This study is a prospective cohort study done on 33 low-vision patients (16 males and 17 females) recruited from the Low Vision Clinic at Menoufia University Hospitals from April 2018 to October 2019. Their age ranged from 8 to 75 years. A total of 30 patients had bilateral central scotoma with one dominant eye and three patients had unilateral central scotoma in the seeing eye of a single-eyed patient.
A written informed consent was obtained from all patients or their legal guardians to participate in the study and for publication of data. The study was approved by the Ethics Committee of Human Rights, Faculty of Medicine, Menoufia University. All procedures were performed under the tenets of the Helsinki Declaration.
The inclusion criteria for the patients included in this study were as follows: all patients should have maculopathy that is stable and nonprogressive for at least 6 months before the training and the central scotoma ranged from 10 to 20° from the point of fixation as seen in the visual field of the patient. All patients should be able to read and to be able to practice EV training during reading. The exclusion criteria were patients with ocular diseases other than maculopathy that may affect the visual function, for example, significant media opacity, such as cataract or corneal opacity, and retinal disorders affecting peripheral and central retina, for example, advanced retinitis pigmentosa. In addition, central causes of visual impairment, for example, head injury were excluded from the study. If the patient discontinued the EV training, during the training period (2 months), he/she was excluded from the study.
All patients were subjected to complete history taking, including personal history, ocular history, and history of systemic diseases or medications.
All patients were subjected to full ophthalmological examination including best-corrected visual acuity (BCVA) for distance, which was checked at 3 m distance, from Lea translucent symbol distance visual acuity chart ‘2000’, and BCVA for near at 25 cm distance from Lea symbols near visual acuity chart (GOOD-LITE company in the USA and Canada). This was followed by ophthalmological examination and relevant investigation to reach the proper diagnosis, including slit-lamp examination of both eyes to examine the anterior segment of the eye for the presence of any ocular disorder, such as cataract, intraocular pressure measurement using applanation tonometer to exclude glaucoma, and fundus examination to determine the cause of maculopathy, and to exclude the presence of any of the exclusion criteria by using direct or indirect ophthalmoscope. Investigations like fundus fluorescein angiography and ocular tomography were done when required. The eye that was used in training was usually the dominant eye of the patient.
For each patient, the visual field was tested by the OCTOPUS 101 visual field analyzer (Haag-Streit AG, Koniz, Switzerland) to test the PRL’s position, sensitivity, and stability of fixation, using the low-vision program to test the magnitude of the central scotoma and the location of the best PRL (the nearest macula region with the highest visual sensitivity). A white V test light stimulus with a maximum light stimulus intensity of 1910 cd/m2 moved at a speed of 4°/s was used in this program .
Reading speed was calculated by asking the patient to read for one minute from the Come closer–reading (Arabic and English) visual acuity test (made by SEEnoir project in Linnaeus University in Kalmar, Sweden in 2008 and translated into many languages and then translated to Arabic by the Vision Rehabilitation Department, German Jordanian University) at 25 cm under standard room lighting and counting the number of words read per minute (wpm). The training was practiced with very simple sentences to be easy for every one even with basic literacy skills . The objective position of a patient’s PRL was assessed with a direct ophthalmoscope by making the patient identify and fixate on a target transmitted via the direct ophthalmoscope fixation aperture .
The procedure used to assess the direction of EV, using the patient’s best eye, involved patient sitting in order to best retinal area test with a sign in the center to be at the level of the eye, and the distance can be modified according to the degree of visual acuity of each patient. The patient was then told not to look directly at the sign in the middle but was asked to look around it at 12, 3, 6, and 9 O’clock positions. The patient was asked to compare the ability to see the sign in the four directions of gaze. If the symbol was more visible in one or more positions, then the areas in between were tested. For example, if the patient was more aware of the symbol when looking at 12 and 3 O’clock positions, the vision should be tested again at 1 and 2 O’clock positions .
After the best directions of EV, giving the best visual acuity for both near and far vision and the location of the PRL, were identified, then the patients were randomized using a computer-generated random number table into two groups:
- Group 1: the patients were trained to use the best direction of EV with the appropriate optical low-vision device, using the suitable magnification for every patient, for training with one-hour weekly session. The patients and their guardians were educated and trained to use EV with the low-vision devices at home for reading at the focal length of the devices, such as magnifying glasses, magnifiers that may be stand or hand held, and telescopes for near, and while viewing distance target at about 2 m by telescopes for at least 15 min/day for each distance.
- Group 2: the patients were trained for using the best direction of EV with nonoptical low-vision devices (large print size) for reading in a weekly session lasting about one hour and home training for 15 min daily sessions for each far and near vision.
Then, they were all encouraged to use EV in their daily life in recognizing faces, reading newspapers, watching TV, etc.
Patients were educated to adopt eccentric fixation , and after 2 months of training sessions and home training, the effect of EV training was evaluated by using the BCVA for near and distance and the reading speed for the two groups (group 1 and group 2).
Data were collected and entered into the computer using the Statistical Package for Social Sciences program (SPSS, version 20; IBM Inc., Chicago, Illinois, USA). Data were entered as numerical or categorical data, as appropriate. Quantitative data were expressed as mean and SD, whereas qualitative data were expressed as frequency and percentage.
Analytical statistics were done using χ2-test, Fisher’s exact test, and Paired t-test. P value was considered statistically significant when it was less than 0.05.
| Results|| |
This study included 33 patients, comprising 16 (48.5%) males and 17 (51.5%) females. Their age ranged from 8 to 75 years (mean=41.7±26.2). Positive consanguinity was reported in 13 (39.4%) patients, whereas 20 (60.6%) patients reported negative consanguinity. The right eye was used in training in 18 (54.5%) patients and the left eye was used in 15 (45.5%) patients. The dominant eye was used in EV training in 30 (90.9%) patients and the only eye of single-eyed patients was used in EV training in three (9.1%) patients ([Table 1]).
The distribution of the diseases causing the central scotoma was nine (27.3%) age-related macular degeneration, nine (27.3%) Stargardt’s disease, five (15.2%) myopic macular degeneration, three (9.1%) cone dystrophy, three (9.1%) fundus flavimaculatus, two (6.1%) optic neuritis, one (3%) retinopathy of prematurity, and one (3%) toxoplasmosis scar ([Table 1]).
In all study cases, after 2 months of EV training, the near BCVA and mean reading speed significantly improved (P<0.001). However, the far BCVA did not significantly improve (0.1 LogMar on average). The mean near BCVA improved from 0.97±0.19 LogMar to 0.63±0.26 LogMar (P<0.001), and the mean reading speed improved from 26.48±9.31 to 53.82±10.81 wpm (P<0.001, [Table 2]).
|Table 2 Changes in visual characteristics after 2 months of eccentric viewing training|
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The group that used low-vision devices with EV training (group 1, 51.5%) showed significantly more improvement in the near BCVA (0.41±0.17 LogMar) than the group that did not use the low-vision devices (group 2, 48.5%) (0.78±0.28 LogMar). In addition, the group that used low-vision devices with EV training showed significantly more improvement in the far BCVA (0.75±0.17 LogMar) than the group that did not use the low-vision devices (1.02±0.28 LogMar) ([Table 3]).
|Table 3 Comparison between near BCVA and far BCVA in the group that used optical low-vision devices (group 1) and the group that did not use optical low-vision devices (group 2) after EV training|
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After analysis of the direction of EV, the PRL location determined by the direct ophthalmoscope, and the visual field in every patient, we noticed that there was agreement between the direction of EV, PRL location by the direct ophthalmoscope, and the visual field in two-thirds of the patients (22 patients, 66.7%, agreement group), and there was disagreement between the direction of EV, PRL location by the direct ophthalmoscope, and the visual field in one-third of the patients (11 patients, 33.3%, disagreement group), [Table 1].
In the agreement group, most patients presented their PRL in the nasal, superior, and superonasal directions as follows: five (22.7%), four (18.2%), and four (18.2%), respectively, whereas three (13.6%) patients presented their PRL in the temporal direction, two (9.1%) patients in the inferior direction, two (9.1%) patients in the superotemporal direction, one (4.5%) patient in the inferonasal direction, and one (4.5%) patient in the inferotemporal direction ([Table 4]).
|Table 4 Distributions of preferred retinal loci in the group that showed agreement between eccentric viewing, preferred retinal locus, and visual field|
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There was no statistically significant difference in the initial far BCVA (LogMar) between the agreement group (1.01±0.25) and the disagreement group (1±0.27), but there was a statistically significant difference between the initial near BCVA (LogMar) and reading speed (words/min) between the two groups ([Table 5]).
|Table 5 Comparison of basic visual characteristics between the agreement and disagreement groups|
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There was a statistically significant difference in the near BCVA, after training, between the agreement group (0.52±0.18 LogMar) and the disagreement group (0.85±0.27 LogMar). In addition, there was a statistically significant difference in the reading speed, after training, between the agreement group (59.09±7.89 wpm) and the disagreement group (43.27±7.75 wpm), but there was no statistically significant difference between the two groups in the far BCVA ([Table 5]).
In the agreement group, there was a significant improvement in the near BCVA from 0.93±0.14 LogMar before EV training to 0.52±0.18 LogMar at the end of EV training. In addition, there was a significant improvement in the reading speed after EV training (59.09±7.89 wpm) than before training (29.55±8.06 wpm). Similarly, in the disagreement group, there was a significant improvement in the near BCVA from 1.06±0.25 LogMar before EV training to 0.85±0.27 LogMar at the end of EV training, with a significant improvement in the reading speed after EV training (43.27±7.75 wpm) than before the training (20.36±8.91 wpm). There was no significant improvement in the far BCVA in both the agreement and disagreement groups before and after EV training ([Table 5]).
| Discussion|| |
Patients with a central scotoma use relatively healthy peripheral areas of the retina to view objects . However, this viewing technique may appear unnatural. By time, nearly all individuals with CVL will select a ‘PRL’ for EV ,.
However, the factors influencing the production of a PRL at a particular location relative to the scotoma and their characteristics are still not understood [23-25]. Many studies have also shown that the location of PRLs will vary depending on the type of macular disease present, the target size, the background luminance level, and the functional task ,,,.
In the present study, the PRLs were preferentially located in the nasal, superior and superonasal areas as follows: 22.7, 18.2, and 18.2%, respectively, in relation to the fovea, in the agreement group (group A). In contrast, Jeong and Moon  in 2011 reported that the PRLs were preferentially located in the temporal (20%) and superotemporal (20%) retina in relation to the fovea in the accordance group in their study.
In the present study, after 2 months of EV training, the near BCVA significantly improved from 0.97±0.19 to 0.63±0.26 LogMar. In contrast, Jeong and Moon  found that after 2 weeks of EV training, there was little to no improvement in near BCVA, which may be owing to their short duration of training. However, in 2013, Verdina et al.  made EV training using a microperimeter and audible feedback that encouraged the use of a trained retinal locus and found a significant improvement in near VA from 0.67±0.18 to 0.56±0.16 LogMar in 12 patients with Stargardt’s disease after 10 weeks of follow-up. Similarly, Palmer et al.  and Vukicevic and Fitzmaurice  reported a significant improvement (P<0.001) in the near VA in all participants in the EV group.
The evaluation of reading speed has been suggested to provide a more useful indicator of visual output in individuals with CVL than the evaluation of near VA alone, as reading is a more challenging visual function than finding few optotypes on a visual acuity chart ,. In this study, after 2 months of EV training, the mean reading speed significantly improved from 26.48±9.31 to 53.82±10.81 wpm, which was in agreement with Palmer et al. , who collected data from 300 patients who practiced EV training and analyzed their data and found that the starting mean reading speed was 48 wpm and improved to 71.9 wpm, which was statistically significant. Similarly, Kasten et al.  found a significant increase (P<0.05) in the mean reading speed from 57.5±33.0 to 77.3±52.0 wpm after training. Seiple et al.  found that the increase in reading speed was statistically highly significant. Moreover, Jeong and Moon  studied the effect of EV training in 30 patients with bilateral central scotoma owing to various causes, and they found that there was a significant improvement in the reading speed (P<0.001).
Thus, there is agreement that EV training has a very effective role in improving the reading speed and hence the reading ability of the patient. In contrast, in 2011, Seiple et al.  found that there was an average decrease of 8.4±7.2 wpm in the reading speed for the EV training group in their research. We also found that the high starting reading speeds resulted in high finishing reading speeds. This is not surprising as these learners probably had a better visual acuity and a smaller central scotoma.
However, in the present study, there was no significant improvement in the far BCVA (0.1 LogMar on average), which is in contrast to Deruaz et al. , who reported a significant improvement (P=0.022) in distance VA after EV training that was administered using a SLO. This may be owing to their usage of SLO in their training and its accuracy in detecting the best PRL . Many other studies were in agreement with the current study, as they reported no significant change (P>0.05) in distance VA after EV training ,,,. Clearly, there is no proof of the effect of EV training on distance VA, and more work is required.
In the present study, we compared between two groups of patients; 17 patients (group 1) were trained for using the best direction of EV with the appropriate optical low-vision device with the suitable magnification for near and far vision for every patient (51.5%), and 16 patients (group 2) were trained for using the best direction of EV with nonoptical low-vision devices (large print size) for reading and EV only for far vision (48.5%). After 2 months of training, the group that used low-vision devices with EV training showed significantly more improvement in the near BCVA (0.41±0.17 LogMar) than the group that used EV training only (0.78±0.28 LogMar). The group that used low-vision devices with EV training showed also significantly more improvement in the far BCVA (0.75±0.17 LogMar) than the group that used EV training only (1.02±0.28 LogMar).
After analysis of the direction of EV, PRL location by the direct ophthalmoscope, and the visual field in every patient, there was agreement between the direction of EV, PRL location by the direct ophthalmoscope, and the visual field in two-thirds of the patients (22 patients, 66.7%, agreement group), and there was disagreement between the direction of EV, PRL location by the direct ophthalmoscope, and the visual field in one-third of the patients (11 patients, 33.3%, disagreement group). The agreement group showed significantly more improvement in the near BCVA and reading speed after training than the disagreement group, which indicates that the agreement between the subjective direction of EV, PRL location by the direct ophthalmoscope, and the visual field results in a more precise location of the PRL. So, the patients can be educated for EV easily and give better results after training.
The technique used in the present study to test and prepare for EV is simple, affordable, and efficient for low-vision rehabilitation in developing countries as it does not require costly equipment.
| Conclusion|| |
EV training can be used as a very effective method for low-vision rehabilitation in patients presenting with central scotomas, and it can give very good results by using simple and inexpensive equipment. The agreement between the subjective direction of EV, PRL location by the direct ophthalmoscope, and the visual field results in a more precise location of the PRL. So, the patients can be educated for EV easily and give better results after training.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Fletcher DC, Schuchard RA, Renninger LW. Patient awareness of binocular central scotoma in age-related macular degeneration. Optom Vis Sci 2012; 89:1395–1398.
Crossland MD, Culham LE, Kabanarou SA, Rubin GS. Preferred retinal locus development in patients with macular disease. Ophthalmology 2005; 112:1579–1585.
Chung ST. The Glenn A. Fry Award Lecture 2012: Plasticity of the visual system following central vision loss. Optom Vis Sci 2013; 90:520.
Kavitha V, Heralgi MM, Parkar M, Harogoppa S. Quality of life in children with low vision following use of low vision aids. Taiwan J Ophthalmol 2020; 50:79–80.
Hassan SE, Ross NC, Massof RW, Stelmack J. Changes in the properties of the preferred retinal locus with eccentric viewing training. Optom Vis Sci 2019; 96:79–86.
Schuchard RA. Preferred retinal locus: a review with application in low vision rehabilitation. Low Vis Vis Rehabil 1994; 7:243–256.
Morales MU, Saker S, Wilde C, Rubinstein M, Limoli P, Amoaku WM. Biofeedback fixation training method for improving eccentric vision in patients with loss of foveal function secondary to different maculopathies. Int Ophthalmol 2020; 40:305–312.
Holocomb JG, Goodrich GL. Eccentric viewing training. J Am Optom Assn 1976; 47:1438–1443.
Kaltenegger K, Kuester S, Altpeter-Ott E, Eschweiler GW, Cordey A, Ivanov IV, Trauzettel-Klosinski S. Effects of home reading training on reading and quality of life in AMD − a randomized and controlled study. Graefe’s Arch Clin Exp Ophthalmol 2019; 257:1499–1512.
Prahalad KS, Coates DR. Asymmetries of reading eye movements in simulated central vision loss. Vision Res 2020; 171:1–10.
Lorenzini MC, Walter W. Factors related to the use of magnifying low vision AIDS: a scoping review. J Vis Impair Blind 2019; 99:1–13.
Kasten E, Haschke P, Meinhold U, Oertel-Verweyen P. A computer program for training eccentric reading in persons with central scotoma. J Vis Impair Blind 2010; 104:303–311.
Palmer S, Logan D, Nabili S, Dutton GN. Effective rehabilitation of reading by training in the technique of eccentric viewing: evaluation of a 4-year programme of service delivery. Br J Ophthalmol 2010; 94:494–497.
Romayananda N, Wong SW, Elzeneiny IH, Chan GH. Prismatic scanning method for improving visual acuity in patients with low vision. Ophthalmology 1982; 89:937–945.
Flammer J, Drance SM, Jenni A, Bebie H. JO, STATJO. Programs for investigating the visual field with the Octopus automatic perimeter. Can J Ophthalmol 1983; 18:115–117.
Vingolo EM, Cavarretta S, Domanico D, Parisi F, Malagola R. Microperimetric biofeedback in AMD patients. Appl Psychophysiol Biofeedback 2007; 32:185–189.
Jeong JH, Moon NJ. A study of eccentric viewing training for low vision rehabilitation. J Korean Ophthalmol 2011; 25:409–416.
Pijnacker J, Verstraten P, VanDamme W, Vandermeulen J, Steenbergen B. Rehabilitation of reading in older individuals with macular degeneration: a review of effective training programs. Neuropsychol Dev Cogn B Aging Neuropsychol Cogn 2011; 18:708–732.
Crossland MD, Engel SA, Legge GE. The preferred retinal locus in macular disease: toward a consensus definition. Retina 2011; 31:2109–2114.
Fine EM, Rubin GS. Reading with simulated scotomas: attending to the right is better than attending to the left. Vision Res 1999; 39:1039–1048.
Fletcher DC, Schuchard RA. Preferred retinal loci relationship to macular scotomas in a low-vision population. Ophthalmology 1997; 104:632–638.
Sunness JS, Applegate CA, Haselwood D, Rubin GS. Fixation patterns and reading rates in eyes with central scotomas from advanced atrophic age-related macular degeneration and Stargardt disease. Ophthalmology 1996; 103:1458–1466.
Duret F, Issenhuth M, Safran AB. Combined use of several preferred retinal loci in patients with macular disorders when reading single words. Vision Res 1999; 39:873–879.
Verdina T, Giacomelli G, Sodi A, Pennino M, Paggini C, Murro V et al.
Biofeedback rehabilitation of eccentric fixation in patients with Stargardt disease. Eur J Ophthalmol 2013; 23:723–731.
Lei H, Schuhard RA. Using two preferred retinal loci for different lighting conditions in patients with central scotomas. Invest Ophthalmol Vis Sci 1997; 38:1812–1818.
Schuchard RA, Naseer S, de Castro K. Characteristics of AMD patients with low vision receiving visual rehabilitation. J Rehabil Res Dev 1999; 36:294–302.
Vukicevic M, Fitzmaurice K. Eccentric viewing training in the home environment: can it improve the performance of activities of daily living? J Vis Impair Blind 2009; 103:277–290.
Seiple W, Szlyk JP, McMahon T, Pulido J, Fishman GA. Eye-movement training for reading in patients with age-related macular degeneration. Invest Ophthalmol Vis Sci 2005; 46:2886–2896.
Seiple W, Grant P, Szlyk JP. Reading rehabilitation of individuals with AMD: Relative effectiveness of training approaches. Invest Ophthalmol Vis Sci 2011; 52:2938–2944.
Deruaz A, Goldschmidt M, Whatham AR, Mermoud C, Lorincz EN, Schnider A, Safran AB. A technique to train new oculomotor behavior in patients with central macular scotomas during reading related tasks using scanning laser ophthalmoscopy: immediate functional benefits and gains retention. BMC Ophthalmol 2006; 6:35.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]