Role of eccentric viewing training with microperimeter for low vision rehabilitation in multifocal choroiditis: Case report.

A 21-year-old student with healed multifocal choroiditis involving the macula presented with difficulty in seeing distance and reading her college books. Based on microperimetr'y, the location of her preferred retinal locus and the position of new trained retinal locus (TRL) were identified. With multiple sessions of biofeedback training, her mean retinal sensitivity improved from 4.8 to 8.8 dl, distance vision from 3/60 to 6/36, and near vision from N32 to N8 in the right eye. At 6-month follow-up, her TRL position and visual acuity were found to be stable. This case report highlights that eccentric viewing training using microperimeter can significantly improve the efficiency of functional vision in patients with choroiditis.

Low-vision intervention for oculocutaneous albinism in a Tertiary Eye Care Hospital in India.

PURPOSE: The objective of this study on patients with albinism in different age groups was to compare their level of visual impairment with the low-vision intervention (LVI) and its benefit. METHODS: The medical records of 72 patients with low vision secondary to albinism who were referred to the low vision care clinic from 2015 to 2017 were analyzed. This included the demographic profile such as age, gender, occupation, ocular history, visual acuity status, and type of low-vision device (LVD) preferred. The LVDs prescribed and its subsequent improvement was compared. RESULTS: In this data, 70 (97.2%) people had oculocutaneous albinism and 2 (2.8%) had ocular albinism. Majority of the patients had hyperopic astigmatism 42 (58.3%) and with-the-rule astigmatism 58 (93.5%). Presenting mean visual acuity for distance was noted to be 0.88 logMAR which improved to 0.83 logMAR with the help of spectacle correction. The most commonly prescribed LVD was a dome magnifier for 15 (34.9%) patients. In all the patients, there was statistically significant improvement (P < 0.05) in near vision with the help of LVDs. CONCLUSION: The study highlights the importance of appropriate LVI for each subdivided age group. Patients with albinism who have received medical and surgical treatment have no or a limited role in restoring useful vision.

Changes in visual acuity using low vision devices in patients with Leber hereditary optic neuropathy: A retrospective study.

Purpose: This study was conducted to estimate the visual acuity improvement in patients with Leber hereditary optic neuropathy (LHON) with the help of low vision devices (LVDs) and to analyze the types of distant and near LVDs prescribed to the patients with LHON. Methods: A retrospective case review of 74 subjects with LHON who were referred to a low vision care clinic at a tertiary eye center from 2016 to 2019 were recruited. The reason for referral was assessed from the patients' electronic medical records (EMR). Demographic data of the patients, visual acuity status, type of LVD prescribed, and visual acuity improvement with LVD were documented. Results: Out of 74 patients, 91.9% (n = 68) were male, and the median age of patients was 21 (16) years. A 4× monocular telescope was prescribed for 2.7% of patients (n = 2) and SEETV binocular telescope for 1.4% (n = 1) was advised for distance. The most commonly prescribed near LVD was the 6× cutaway stand magnifier for 22 patients (29.7%). Four patients (5.4%) were prescribed with Notex, the most commonly prescribed non-optical LVD. Niki CCTV (12.2%, n=9) was the most commonly prescribed assistive device. The subjects were divided into three groups based on age: group I consisted of those <18 years of age, group II 18-40 years, and group III >40 years for the interpretation of visual improvement. There was a statistically significant improvement (group I: P < 0.001, group II: P < 0.0001, group III: P < 0.003) in near vision with help of LVDs in all three groups. Conclusion: The use of LVDs and rehabilitation can help patients with LHON to lead a better life and will be more beneficial.

Prescribing patterns of low vision devices in patients with cone-related dystrophies.

Purpose: The aim of this study was to elucidate the type of low vision devices (LVDs) prescribed for patients with cone dystrophy, cone-rod dystrophy, and rod-cone dystrophy and to analyze the visual improvement with the devices. Methods: A retrospective review of 300 electronic medical records of patients with cone dystrophy, cone-rod dystrophy, and rod-cone dystrophy referred to the low vision care (LVC) clinic for the first time between 2014 and 2016 at a tertiary eye care center was done. Collected data included the demographic profile of patients, details of LVDs, and best-corrected vision. Results: Out of 300 patients, 62.6% (n = 188) were male and 37.3% (n = 112) were female. Of the cases, 50% (n = 150) had cone-rod dystrophy, 45% (n = 135) had cone dystrophy, and 5% (n = 15) had rod-cone dystrophy. The most commonly prescribed LVD was SEE-TV binocular telescope (n = 6, 2.0%) for distance and dome magnifier (n = 60, 20%) for near. ET-40 dark grey tint (20.6%) was preferred for managing photophobia. There was a statistically significant difference in both distance and near visual acuities with LVDs (P < 0.05) in all categories, except rod-cone dystrophy. Conclusion: Early diagnosis with appropriate prescription of LVDs including tints helps in achieving good quality of vision in patients with cone-related dystrophies.

Development of Immersive Virtual Reality Environment for Assessment of Functional Vision in people with Low Vision: A Pilot Study.

INTRODUCTION: Virtual Reality technology helps in creating virtual environments for evaluation of visual performance of low vision individuals with holistic experience. The purpose of this study was to develop a virtual reality (VR) platform for the objective assessment of functional vision in patients with low vision in two categories, central and peripheral vision loss . MATERIALS AND METHODS: Focus group discussions (FGD) were organized to understand the difficulties faced on a day to day basis by patients with low vision. Based on the results of the focus group discussions, a virtual bank scenario incorporating specific visual tasks was developed. A pilot study was conducted which involved people with normal vision; low vision Patients secondary to central field loss (CFL) and peripheral field loss (PFL). Each subject completed all the tasks in the objective assessment; the data obtained from the assessment were further analyzed to understand the pattern. RESULTS: Comparing the three groups, there was a significant difference in distance (central field loss was lowest) and near visual angle, and three visual search tasks (peripheral field loss was lowest). In assessing the time taken, peripheral field loss group was again found to take the most time to complete tasks. CONCLUSION: Based on a newly developed virtual reality platform, assessment of functional vision of specially abled persons could be tested and was inferior to that of normal sighted persons. in a close to realistic environment. Multiple visual tasks were performed in the virtual environment and the visual performance was compared among all three groups of participants. Participants were matched for age and gender. Irrespective of the nature of tasks, visual performance of the normal group seemed significantly better than people with CFL and PFL.

Partial visual loss disrupts the relationship between judged room size and sound source distance.

Visual spatial information plays an important role in calibrating auditory space. Blindness results in deficits in a number of auditory abilities, which have been explained in terms of the hypothesis that visual information is needed to calibrate audition. When judging the size of a novel room when only auditory cues are available, normally sighted participants may use the location of the farthest sound source to infer the nearest possible distance of the far wall. However, for people with partial visual loss (distinct from blindness in that some vision is present), such a strategy may not be reliable if vision is needed to calibrate auditory cues for distance. In the current study, participants were presented with sounds at different distances (ranging from 1.2 to 13.8 m) in a simulated reverberant (T60 = 700 ms) or anechoic room. Farthest distance judgments and room size judgments (volume and area) were obtained from blindfolded participants (18 normally sighted, 38 partially sighted) for speech, music, and noise stimuli. With sighted participants, the judged room volume and farthest sound source distance estimates were positively correlated (p < 0.05) for all conditions. Participants with visual losses showed no significant correlations for any of the conditions tested. A similar pattern of results was observed for the correlations between farthest distance and room floor area estimates. Results demonstrate that partial visual loss disrupts the relationship between judged room size and sound source distance that is shown by sighted participants.

Preference of low vision devices in patients with central field loss and peripheral field loss.

PURPOSE: The objective of this study was to estimate the profile of patients visiting low vision care clinic at a tertiary eye care center in India and to analyze the preference of low vision devices (LVD). METHODS: A retrospective review was done for 450 patients with low vision who were referred to the LVC clinic from January 2019 to December 2019. The participants were categorized into two groups as central field loss (CFL) and peripheral field loss (PFL). Demographic profile details and low vision device preference were documented. RESULTS: Out of 450 patients, 242 (53.8%) were diagnosed to have CFL and 208 (46.2%) had PFL. The median age of the overall patients was 34.5 years. Overall, 323 (71.8%) were men and 127 (28.2%) were women. Cone dystrophy (21.1%) was the major cause of low vision among atrophic changes (54.1%) in CFL, and retinitis pigmentosa (81.2%) was the majority in retina related changes (81.7%) in PFL. Overall, 71.3% of the low vision patients preferred LVD. CFL group (76%) preferred LVD more than PFL group (65.9%). Almost 34% of the patients in both CFL and PFL group have preferred half eyes and Ashperics, followed by 32.5% in CFL and 28.1% in PFL preferred dome magnifiers. Statistically significant improvement in distance and near vision with the help of LVD was noted. CONCLUSION: The use of LVD can help patients with low vision in restoring useful vision, where medical and surgical treatment have no or a limited role.

Use of augmented reality technology for improving visual acuity of individuals with low vision.

Purpose: The objective of this study was to analyze the visual acuity improvement in patients with low vision using augmented reality device who presented to the low vision care (LVC) clinic at a tertiary eye care center. Methods: A prospective study of 100 patients with low vision who were referred to the LVC clinic between July and December 2018 was done. Demographic data and visual acuity improvement assessed using augmented reality (AR) technology paired with Samsung Gear headset were documented. Results: Out of 100 patients, 74 were male and 26 were female. The median age of the overall patients was 36 (25.5) years. In 100 patients, 21% patients were found to have central field loss (CFL), 35% patients have peripheral field loss (PFL), and 44% patients were found to have overall blurred vision (OBV). Majority of the subjects with CFL (47%) and OBV (37%) has a moderate visual impairment and in PFL group (26%), severe visual impairment was more. Cone dystrophy (9%) was found to be the major cause of CFL group, retinitis pigmentosa (22%) in the case of PFL group, and optic atrophy (10%) in the case of OBV group. The median distance visual acuity 0.9 log MAR improved to 0.2 log MAR (P < 0.0001) and median near visual acuity 0.4 log MAR improved to 0.1 log MAR with a P value of < 0.0001 using AR device. Conclusion: The use of an AR device can help patients with low vision to improve their residual vision for better visual performance.

Low-vision intervention in individuals with age-related macular degeneration.

Purpose: The objective of this study was to estimate the level of visual impairment in patients diagnosed to have age-related macular degeneration (ARMD) who presented to low-vision care (LVC) clinic at a tertiary eye care center in India, to analyze the type of distant and near devices prescribed to them and to compare the visual benefit in different age groups among patients with ARMD. Methods: A retrospective review was done for 91 patients with low-vision secondary to ARMD who were referred to the LVC clinic from 2016 to 2017. Demographic profile: age, gender, occupation, ocular history, visual acuity status, and type of low-vision device (LVD) preferred were documented. The details of LVDs and subsequent improvements were noted. Result: Of the 91 patients, 64 (70.3%) were men and 27 (29.7%) were women. Of the cases which were referred, 36.26% had a severe visual impairment (VI), 32.96% had moderate VI, 28.57% had mild VI, and 5.49% had profound VI. The majority of the patients had myopia 57 (62.63%), followed by hyperopia in 25 (27.47%) subjects. The subjects were divided into three groups based on age 40-65 years, 66-75 years, and above 75 years for the analysis of VI. There was a statistically significant improvement (P < 0.01) in near vision with the help of LVDs in all three groups. SEE TV binocular telescope was the most commonly prescribed LVD for viewing distant objects. The most commonly preferred magnifier for near work was half-eye spectacle (56%) followed by stand magnifier (9.9%) and portable video magnifier (9.9%). Conclusion: The use of LVDs can help these patients with ARMD in cases where medical and surgical treatment have no or a limited role in restoring useful vision.

The accuracy of auditory spatial judgments in the visually impaired is dependent on sound source distance.

Blindness leads to substantial enhancements in many auditory abilities, and deficits in others. It is unknown how severe visual losses need to be before changes in auditory abilities occur, or whether the relationship between severity of visual loss and changes in auditory abilities is proportional and systematic. Here we show that greater severity of visual loss is associated with increased auditory judgments of distance and room size. On average participants with severe visual losses perceived sounds to be twice as far away, and rooms to be three times larger, than sighted controls. Distance estimates for sighted controls were most accurate for closer sounds and least accurate for farther sounds. As the severity of visual impairment increased, accuracy decreased for closer sounds and increased for farther sounds. However, it is for closer sounds that accurate judgments are needed to guide rapid motor responses to auditory events, e.g. planning a safe path through a busy street to avoid collisions with other people, and falls. Interestingly, greater visual impairment severity was associated with more accurate room size estimates. The results support a new hypothesis that crossmodal calibration of audition by vision depends on the severity of visual loss.

Comparison of Visual Parameters Between Normal Individuals and People with Low Vision in a Virtual Environment.

Patients with Low vision are known to experience difficulties in executing activities of daily living and visual search due to reduction in vision. There is a need to translate clinical parameters into a real world that is relevant so as to understand the patient's functional vision; this can be possible with virtual reality (VR). This prospective study included 53 normal and 30 low vision subjects older than 18 years of age in a tertiary care center. The low vision subjects were further classified into peripheral field loss (PFL) and central field loss (CFL). A VR bank environment was developed with multiple tasks that aimed at assessing reading for distance and near, identification of objects against various contrast levels and mobility. Based on the normative data obtained a scoring system was developed to quantify the visual performance between normal and low vision subjects. A significant difference was found in the performance between the normal and low vision subjects in the VR environment. The overall VR performance score was lower in subjects with PFL 56.65 (IQR 19.4) than CFL 63.25 (IQR 10.83); however, both of them were lower compared with normal subjects 87 (IQR 4.6) p < 0.001. These findings suggest that performance of low vision subjects was worse than normal subjects in VR environment and it is important to plan and prioritize assessment and rehabilitation interventions for low vision subjects with a more holistic performance based approach.

Visual rehabilitation using microperimetric acoustic biofeedback training in individuals with central scotoma.

BACKGROUND: Patients with central scotoma have poor fixation stability and poor visual acuity. Acoustic biofeedback training can be an effective way to train such patients to eccentrically fixate. This study analyses the mean retinal sensitivity, saccadic velocity, and fixation stability after acoustic biofeedback training and shows correlation with age and scotoma size. METHODS: Patients with irreversible central scotoma in both the eyes secondary to macular diseases were selected. After undergoing comprehensive low vision assessment, 19 patients who were willing were recruited for the acoustic biofeedback training to the better eye in 10 sessions, using the MP-1 Microperimeter. Mean retinal sensitivity, saccadic velocity, fixation stability before and after the acoustic biofeedback were recorded. RESULTS: There were 17 men and two women. Ages ranged from 19-94 years (mean 54.63 ± 24.66). The scotoma size ranged from four to 20 degrees. Ten patients had age-related macular degeneration, four had Stargardt disease, three had traumatic macular scar, two had scarred myopic choroidal neovascular membrane, and one had myopic macular degeneration. The vision improved from 1.06 ± 0.36 to 0.86 ± 0.33 logMAR (p < 0.0001). The mean retinal sensitivity improved from 2.1 ± 2.9 dB to 2.7 ± 3.1 dB (p = 0.01), with negative correlation with age (p = 0.01) and scotoma size (p = 0.02). Fixation stability improved with reduction in the bivariate contour ellipse area (p = 0.01). It showed negative correlation with age (p = 0.02) and scotoma size (p = 0.10). The saccadic velocity reduced from 0.34°/second to 0.26°/second but was not significant (p > 0.99). The majority (58 per cent) had their preferred retinal locus superior to the fovea. There was good agreement between bivariate contour ellipse area and MP-1 Microperimeter inbuilt fixation parameters. The effect was maintained at six months with slight reduction in fixation stability. CONCLUSION: Acoustic biofeedback can improve fixation behaviour, visual acuity and retinal sensitivity in patients with central scotoma. The results are better with younger age and smaller scotoma size.

Factors influencing the choice of low-vision devices for visual rehabilitation in Stargardt disease.

BACKGROUND: Stargardt disease is the most common cause of juvenile macular degeneration leading to early central visual loss. Dispensing of correct low-vision devices based on the residual visual function and specific visual requirements of a patient can result in a positive outcome. It is important to know the factors involved in the selection of these devices. This study was undertaken to assess these factors. METHODS: Patients with Stargardt disease referred to a low-vision clinic underwent evaluation of visual status, disease stage, visual requirements and lifestyle. They were evaluated for suitability for successful use of various low-vision devices. Their education level and occupation were noted. They were counselled regarding the proper use of the devices and lifestyle modifications. For patients with extensive use of computers, modifications related to contrast, font size and audio software were explained. RESULTS: Among the 97 patients in the study (age range 7-66 years, mean 23.7 ± 13.1), there were 49 (50.5 per cent) students, 36 (37.1 per cent) employed, eight (8.2 per cent) unemployed, and four (4.2 per cent) homemakers. Except for seven patients (7.2 per cent), all were literate, with education ranging from primary school to college graduation. The presenting visual acuity for distance was 0.10-1.47 (0.79 ± 0.28), and for near was N4-N40 (N9.95 ± 6.65). This acuity showed positive correlation with age (p < 0.0001, R2 = 0.16) and with magnification required (p < 0.0001, R2 = 0.26). Patients above 40 years preferred higher adds and half-eye glasses, whereas younger patients preferred dome magnifiers. The occupation also influenced the choice. Disease stage was seen to affect the choice with advanced stages requiring higher magnifiers (p = 0.03, R2 = 0.11). Duration of disease and the magnification of low-vision devices showed a positive correlation (p = 0.03, R2 = 0.049). CONCLUSIONS: Age, presenting visual acuity, disease stage, duration, education and occupation influenced the choice of low-vision devices in patients with Stargardt disease. However, they appear to be interdependent and a larger, controlled study is required to provide information on the individual effect.

Visual rehabilitation of patients with low vision in uveitis.

PURPOSE: To elucidate the clinical profile of visual impairment (VI) and rehabilitation of the uveitic patients with irreversible low vision. METHODS: Retrospective analysis of visual rehabilitation of patients with uveitis suffering from poor vision with low vision devices (LVD). RESULTS: Most common cause of uveitis was choroiditis (46.29%), followed by retinitis (25.92%), retinochoroiditis (18.51%), and chronic panuveitis sequelae (9.25%). Of these 54 cases, 35.18% had moderate VI, 25.92% had severe VI, 20.37% had mild VI, and 18.51% had profound VI or blindness. Statistically significant improvement (P < 0.05) in near vision was seen in choroiditis (52%) and retinitis (72%), whereas clinically significant improvement in distance vision was found in patients with choroiditis. Most commonly prescribed LVD was half-eye prismatic spectacle magnifier (22.2%). CONCLUSION: Rehabilitation of the uveitic patients with low vision is challenging. LVD may be a beneficial tool in these patients to help them perform their day-to-day activities independently.

Hospital anxiety and depression scale assessment of 100 patients before and after using low vision care: A prospective study in a tertiary eye-care setting.

PURPOSE: Assessment of anxiety and depression in patients attending low vision care (LVC) using Hospital Anxiety and Depression Scale (HADS). METHODS: In this prospective, observational study, 100 patients with best-corrected visual acuity (BCVA) worse than 6/18 in the better eye or limitation of field of vision to <10° from center of fixation were assessed on the depression and anxiety subscales of HADS questionnaire before and after LVC. HADS is a 14-item scale with seven items each for anxiety and depression subscales. Scoring for each item ranges from zero to three. A subscale score >8 denotes anxiety or depression. RESULTS: Mean age at presentation was 38.2 years. Mean duration of symptoms was 9.6 years. Underlying etiology of visual impairment included retinal dystrophy/degeneration (n = 35), disorders of the optic nerve (n = 17), glaucoma (n = 10), diabetic retinopathy (n = 9), age-related macular degeneration (n = 5), uncorrected refractive errors (n = 5), and miscellaneous diseases (n = 19). Mean presenting BCVA in the better eye was 0.83 (±0.64) which improved significantly to 0.78 (±0.63) after LVC (P < 0.001). The HADS-Depression subscale score was comparable for severity of visual impairment for both distance (P = 0.57) and near vision (P = 0.61). Similarly, HADS-Anxiety scores were also comparable for severity of distance (P = 0.34) and near-visual impairment (NVI; P = 0.50). At baseline, mean HADS-Depression and HADS-Anxiety scores were 8.4 (±3.7) and 9.6 (±4.3) points, which improved significantly to 6.0 (±3.4) and 6.7 (±3.7), respectively, after low-vision correction (P < 0.001). CONCLUSION: Low vision correction can significantly improve anxiety and depression indicators in visually impaired patients.

Improvement in distance and near visual acuities using low vision devices in diabetic retinopathy.

PURPOSE: The aim of this study is to elucidate the causes and level of visual impairment (VI) in patients with different pathologies of diabetic retinopathy (DR) who presented to a low vision care (LVC) clinic, to analyze the type of distant and near devices prescribed to them and the visual benefits thereof. METHODS: A retrospective chart review was done for 100 consecutive patients with DR who were referred to the LVC clinic from June 2015 to June 2016. The reason for referral was assessed from the electronic medical records and available fundus photographs, fundus fluorescein angiograms, and optical coherence tomography images by a retina specialist. The details of low-vision devices and subsequent improvements were noted. RESULTS: Of the 100 patients, 52% had moderate VI, 19% mild VI, 16% severe VI, and 13% had profound VI or blindness. The most commonly prescribed low vision device was half-eye spectacles (38.4%). The pathologies which had statistically significant improvement (P < 0.05) in distance vision with low vision devices were DR with disc pallor (4.4% improvement), ischemic maculopathy (11.9% improvement), and plaque of hard exudate (10.1% improvement). However, in all pathologies, there was statistically significant improvement (P < 0.05) in near vision. CONCLUSION: Usually, the patients with DR presented to the LVC clinic with moderate VI. The use of low vision devices can help these patients in cases where medical and surgical treatment have no or a limited role in restoring useful vision.

Partial Visual Loss Affects Self-reports of Hearing Abilities Measured Using a Modified Version of the Speech, Spatial, and Qualities of Hearing Questionnaire.

We assessed how visually impaired (VI) people perceived their own auditory abilities using an established hearing questionnaire, the Speech, Spatial, and Qualities of Hearing Scale (SSQ), that was adapted to make it relevant and applicable to VI individuals by removing references to visual aspects while retaining the meaning of the original questions. The resulting questionnaire, the SSQvi, assessed perceived hearing ability in diverse situations including the ability to follow conversations with multiple speakers, assessing how far away a vehicle is, and the ability to perceptually segregate simultaneous sounds. The SSQvi was administered to 33 VI and 33 normally sighted participants. All participants had normal hearing or mild hearing loss, and all VI participants had some residual visual ability. VI participants gave significantly higher (better) scores than sighted participants for: (i) one speech question, indicating less difficulty in following a conversation that switches from one person to another, (ii) one spatial question, indicating less difficulty in localizing several talkers, (iii) three qualities questions, indicating less difficulty with segregating speech from music, hearing music more clearly, and better speech intelligibility in a car. These findings are consistent with the perceptual enhancement hypothesis, that certain auditory abilities are improved to help compensate for loss of vision, and show that full visual loss is not necessary for perceived changes in auditory ability to occur for a range of auditory situations. For all other questions, scores were not significantly different between the two groups. Questions related to effort, concentration, and ignoring distracting sounds were rated as most difficult for VI participants, as were situations involving divided-attention contexts with multiple streams of speech, following conversations in noise and in echoic environments, judging elevation or distance, and externalizing sounds. The questionnaire has potential clinical applications in assessing the success of clinical interventions and setting more realistic goals for intervention for those with auditory and/or visual losses. The results contribute toward providing benchmark scores for VI individuals.