Case of persistent corneal epithelial damage after cataract surgery leading to diagnosis of vitamin A deficiency.

PURPOSE: To report our findings of reduced full-field electroretinograms (ff-ERGs) and abnormal optical coherence tomographic (OCT) images in a patient with poor visual acuity after cataract surgery who was eventually diagnosed with vitamin A deficiency (VAD). METHODS: This was a clinical study of a patient who complained of blurred vision after cataract surgery. To determine the cause of the reduced vision, we recorded full-field electroretinograms (ff-ERGs) to determine the scotopic and photopic status of the retina. We also performed optical coherence tomography to assess the changes in the retinal structure. Serological tests were performed. RESULTS: A 74-year-old man presented with persistent corneal epithelial damages and reduced vision that developed after conventional cataract surgery. OCT showed an interrupted ellipsoid zone, and fundus autofluorescence (FAF) showed a severe hypofluorescence in the retina of the left eye. The scotopic ff-ERGs were severely reduced, and the photopic ff-ERGs were mildly reduced. Serological examinations revealed a vitamin A concentration < 7 IU/dL (normal, 97-316 IU/dL). Based on these findings, we diagnosed the patient with VAD and started treatment with oral vitamin A supplements. After three months, his visual acuity, ff-ERGs, and OCT findings recovered to normal levels. The amplitudes and implicit times of the RETeval flicker ERGs increased to be within the normal range, and the hypofluorescence of the left eye disappeared. The length of the photoreceptor outer segments increased after the vitamin A supplementation. CONCLUSION: Our findings indicate that the ERGs are helpful for diagnosing patients with VAD associated with persistent corneal epithelial damages.

The Effect of Varied Microperimetric Biofeedback Training in Central Vision Loss: A Randomized Trial.

SIGNIFICANCE: This investigation reports for the first time the effects of different microperimetric biofeedback strategies in visually impaired subjects with central field loss. PURPOSE: This study aimed to evaluate the effects of two MP-3 microperimeter biofeedback strategies on the visual performance of subjects with central vision loss. Moreover, changes between the groups were compared to provide indications of practice with biofeedback stimulation in subjects with central vision loss. METHODS: Using simple randomization, 19 participants were trained according to two different biofeedback stimulation approaches using the MP-3 microperimeter. Patients were assigned to two different groups: subjects trained for 2 days a week (group A) and 3 days a week (group B). The patients in each group were randomized to perform a total of 10 or 15 sessions. RESULTS: Fixation stability increased from 4.5 ± 2.8 to 2.3 ± 2.2° 2 and from 8.2 ± 6.9 to 1.4 ± 1° 2 after 2 and 3 weekly biofeedback training sessions, respectively ( P < .05). Biofeedback training induced a significant improvement of 40.7 and 29.4% in reading speed for groups A and B, respectively ( P < .05). A comparison of two weekly biofeedback training sessions with three weekly biofeedback sessions demonstrated greater fixation stability in group B ( P < .05). CONCLUSIONS: This study concludes that a biofeedback intervention is effective in enhancing oculomotor control in patients with central vision loss. In our study, a more intensive biofeedback strategy seemed to produce significantly better results in terms of functional vision parameters.

Effectiveness of music-based interventions to address well-being in people with a vision impairment: a scoping review.

OBJECTIVES: The objectives of this review were to identify the types of music-based interventions and associated accessibility challenges for people who have visual impairment (VI) and their reported effects on psychological, physiological and social well-being. DESIGN: A scoping review was developed according to the Joanna Briggs Institute methodology and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist and guidelines. A narrative synthesis was conducted to map out the types of music-based interventions undertaken and to compare the therapeutic outcomes. The studies were evaluated according to the music reporting checklist. RESULTS: In total 5082 records were identified, 69 full-text articles were screened and 13 studies were included. Eleven studies included younger children and teenagers, two focused on adults with acquired VI. Ten studies involved active music therapy strategies and three used passive music listening. Eleven of the studies focused on social outcomes and two reported mental health. Although the studies reported that music-based intervention strategies improved psychosocial well-being in people with a VI, conclusions could not be drawn as robust outcome measures were not generally used and only four of the studies included any statistical analysis. CONCLUSIONS: Although potential was evident, details of intervention protocols and training requirements were not sufficiently reported and further, high-quality evidence-based studies are required.

Efficacy of optometric phototherapy: a systematic review.

PURPOSE: To analyse the scientific evidence about the efficacy of Syntonic phototherapy for producing changes in visual function. MATERIAL AND METHODS: A systematic review was performed to obtain studies on the effects of Syntonic phototherapy on vision. A search in health science databases (Medline, Scopus, Web of Science and PsycINFO) for studies published between 1980 and 2022 was conducted in accordance with the principles of Cochrane approach. The search identified 197 articles. Only clinical studies which used the Syntonic phototherapy as a vision therapy for any visual condition were included. Clinical cases and case series were excluded. Following the inclusion criteria, 8 clinical studies met inclusion, 5 of them being pseudo-experimental studies with an equivalent control group and 3 pre-post pseudo-experimental studies. GRADE tool was used to assess the certainty of the evidence of the studies. The GRADE evidence profile for the studies through the Soft table was made to analyse data. RESULTS: The studies analysed seven outcomes: visual symptoms, functional visual fields, visual acuity, contrast sensitivity, deviation (phoria/tropia), stereopsis and reading abilities. Finding table about results (Soft Table) showed that for all outcomes reviewed, all studies yielded very low certainty of evidence. Results revealed a lack of scientific evidence of the efficacy of Syntonic optometric phototherapy to produce changes in the visual function. CONCLUSION: This systematic review found no consistent evidence for the efficacy of Syntonic phototherapy to cause changes in visual function. There is no scientific evidence to support its clinical use for treating any type of visual anomalies.

Effectiveness of visual and acoustic biofeedback eccentric viewing training in conjunction with home exercises on visual function: a retrospective observational review.

The aim of this study is to evaluate the effectiveness of an eccentric viewing training program that combines biofeedback training using micro-perimetry with home exercises on multiple visual function parameters and to explore potential relationships between post-treatment visual function parameters. A retrospective observational review of 27 participants who underwent the training program was performed. Eligible participants were diagnosed with bilateral central scotomas secondary to age-related macular degeneration. All participants undertook up to 15 visual and acoustic biofeedback training sessions and were required to partake in traditional home exercises between sessions. The biofeedback training was conducted in the better eye using the Macular Integrity Assessment microperimeter (MAIA). Distance and near acuity, contrast sensitivity and fixation stability quantified by the P1 and P2 values and the 63% and 95% bivariate contour ellipse area (BCEA) before and after the rehabilitation program were recorded. Significant improvement was noted post-training for distance visual acuity (t(26) = 4938 p = .000), near visual acuity (Z = -4.461 p = .000), contrast sensitivity (Z = -3.647 p = .000) and fixation stability for all measures, including P1 (t(26) = -9.490 p = .000), P2 (t(26) = -7.338 p = 0.000), 63% BCEA (Z = 3.569 p = .000) and 95% BCEA (t(26) = 4.687 p = .000). Significant medium-to-large correlations were also found between most visual function variables. Visual and acoustic biofeedback in conjunction with home exercises has the potential to improve visual function parameters in patients with age-related macular degeneration and irreversible central vision loss.

Impact of Lighting Assessment and Optimization on Participation and Quality of Life in Individuals with Vision Loss.

This pilot study was designed to investigate the effects of a holistic lighting intervention on the quality of life for individuals with low vision. Sixty participants (44 women; median age 69 years) with visual impairment received lighting interventions, including a home visit and consultation in a lighting lab. Assisted by low vision consultants, participants evaluated their performance using the Canadian Occupational Performance Measure (COPM) before and after the intervention. Improvements in visual functioning and quality of life were evaluated using the 39-item National Eye Institute Visual Function Questionnaire (NEI VFQ-39), the Groffman Visual Tracing Test, and the Farnsworth Dichotomous Test (D15). Following the lighting intervention, scores improved for all activities in the COPM (p < 0.01), for near activities and vision-specific role difficulties in the VFQ-39 (p < 0.05), and overall in the D15 test (p < 0.05). These results suggest the intervention provided an effective method for improving the participants' quality of life and performance.

Efficacy of MP-3 microperimeter biofeedback fixation training for low vision rehabilitation in patients with maculopathy.

BACKGROUND: To evaluate the efficacy of MP-3 microperimeter biofeedback fixation training (MBFT) in vision rehabilitation of low-vision patients affected by macular disease with central vision loss. METHODS: Seventeen eyes (7 age-related macular degeneration, 10 myopic maculopathy) of 17 patients were included in this prospective, interventional study. The preferred retinal locus was determined by comprehensive ophthalmoscopic fundus evaluation including fundus photography, autofluorescence, optical coherence tomography, and microperimetry. The rehabilitation consisted of three 10-min sessions per eye to be performed twice per week for 20 consecutive weeks using the MP-3 microperimeter. Best corrected visual acuity (BCVA), reading speed, mean central sensitivity, the percentages of fixation points within specified regions, bivariate contour ellipse area (BCEA) and the 25-item National Eye Institute visual function questionnaire (NEI-VFQ-25) were recorded pre- and post-training. RESULTS: The final BCVA, reading speed and mean central sensitivity all showed significant improvements after rehabilitation (P <  0.0001, P = 0.0013, and P = 0.0002, respectively). The percentages of fixation points located within 2° and 4° diameter circles both significantly increased after training (P = 0.0008 and P = 0.0007, respectively). The BCEA encompassing 68.2, 95.4, 99.6% of fixation points were all significantly decreased after training (P = 0.0038, P = 0.0022, and P = 0.0021, respectively). The NEI-VFQ-25 scores were significantly increased at the end of the rehabilitation training (P <  0.0001). CONCLUSION: Rehabilitation with MP-3 MBFT is a user-friendly therapeutic option for improving visual function, fixation stability, and quality of life in advanced macular disease. TRIAL REGISTRATION: The prospective study was registered with the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ). TRIAL REGISTRATION NUMBER: ChiCTR2000029586 . Date of registration: 05/02/2020.

An Overview of Preferred Retinal Locus and Its Application in Biofeedback Training for Low-Vision Rehabilitation.

Central vision loss (CVL) caused by macular damage generally disables common daily tasks, which cannot be reversed by present treatments. Fortunately, it has been found that biofeedback training by inducing or reinforcing preferred retinal locus (PRL) as an eccentric fixation reference contributes to the improvement of visual performance in patients with CVL. However, the clinical application is still under controversy due to poor knowledge of its fundamental and inconsistent practical standards. This article aims to summarize the possible rationale for the development, location, re-location and evaluating indicators of PRL, and the general apparatus, protocol, and outcome of biofeedback PRL training.

Biofeedback stimulation in the visually impaired: a systematic review of literature.

BACKGROUND: It is estimated that approximately 1.3 billion people live with some form of distance or near visual impairment. Numerous studies have been carried out to evaluate the effects of biofeedback (BF) and establish if it could be a useful tool in vision rehabilitation for various eye diseases. OBJECTIVE: This systematic review aimed: 1) to examine the current evidence of BF efficacy for the rehabilitation of the visually impaired and 2) to describe methodological variations used in previous BF studies to provide recommendations for vision rehabilitation interventions. METHODS: A systematic review was conducted in the Medline, PubMed, Cochrane Library and Web of Science databases to collect documents published between January 2000 and May 2020. Of the 1,960 studies identified, 43 met the criteria for inclusion. The following information was collected from each study: sample size, control group, any eye disease, apparatus used, frequency and number of sessions of BF, main outcomes of training and whether a follow-up was conducted. The first group included studies published as scientific articles in peer-reviewed journals. The second group included abstracts of studies presented at peer-reviewed conferences. Publications were also grouped according to the eye disease treated. RESULTS: 25 articles and 18 peer-reviewed conference abstracts (PRCAs) were included in this review. BF stimulation is a commonly used technique for the treatment of visual impairment caused by macular disease. Most BF studies evaluate the effect of training on the preferred retinal locus (PRL), particularly with regard to fixation location and stability. Across these studies, participants who received BF intervention improved fixation stability and reading speed. High variability in the number of sessions and the duration of BF training was found. Most studies did not use a control group. CONCLUSIONS: The findings of this review present evidence for biofeedback treatment in vision rehabilitation, with improved oculomotor abilities. Currently, it is not possible to formulate evidence-based recommendations for a standard training procedure due to the poor quality of existing randomised controlled trials. High-quality studies are needed to develop standard protocols for a range of eye diseases.

Reduced visual acuity is mirrored in low vision imagery.

Research has examined the nature of visual imagery in normally sighted and blind subjects, but not in those with low vision. Findings with normally sighted subjects suggest that imagery involves primary visual areas of the brain. Since the plasticity of visual cortex appears to be limited in adulthood, we might expect imagery of those with adult-onset low vision to be relatively unaffected by these losses. But if visual imagery is based on recent and current experience, we would expect images of those with low vision to share some properties of impaired visual perception. We examined key parameters of mental images reported by normally sighted subjects, compared to those with early- and late-onset low vision, and with a group of subjects with restricted visual fields using an imagery questionnaire. We found evidence that those with reduced visual acuity report the imagery distances of objects to be closer than those with normal acuity and also depict objects in imagery with lower resolution than those with normal visual acuity. We also found that all low vision groups, like the normally sighted, image objects at a substantially greater distance than when asked to place them at a distance that 'just fits' their imagery field (overflow distance). All low vision groups, like the normally sighted, showed evidence of a limited visual field for imagery, but our group with restricted visual fields did not differ from the other groups in this respect. We conclude that imagery of those with low vision is similar to that of those with normal vision in being dependent on the size of objects or features being imaged, but that it also reflects their reduced visual acuity. We found no evidence for a dependence on imagery of age of onset or number of years of vision impairment.

Grating visual acuity impairment assessed by sweep visually evoked potentials in children with optic pathway tumors unable to perform optotype acuity tests.

PURPOSE: To determine visual impairment due to optic pathway tumors in children unable to perform recognition acuity tests. METHODS: Grating visual acuity scores, in logMAR, were obtained by sweep visually evoked potentials (SVEP) in children with optic pathway tumors. The binocular grating visual acuity deficit was calculated by comparison with age-based norms and then assigned to categories of visual impairment as mild (from 0.10 to 0.39 logMAR), moderate (from 0.40 to 0.79 logMAR), or severe (≥0.80 logMAR). Interocular differences were calculated by subtraction and considered increased if >0.10 logMAR. RESULTS: The participants were 25 children (13 boys; mean ± SD age, 35.1 ± 25.9 months; median age, 32.0 months) with optic pathway tumors (24 gliomas and 1 embryonal tumor), mostly located at the hypothalamic-chiasmatic transition (n=21; 84.0%) with visual abnormalities reported by parents (n=17; 68.0%). The mean grating acuity deficit was 0.60 ± 0.36 logMAR (median, 0.56 logMAR). Visual impairment was detected in all cases and was classified as mild in 10 (40.0%), moderate in 8 (32.0%), and severe in 7 (28.0%) children, along with increased interocular differences (>0.1 logMAR) (n=16; 64.0%). The remarkable ophthalmological abnormalities were nystagmus (n=17; 68.0%), optic disc cupping and/or pallor (n=13; 52.0%), strabismus (n=12; 48.0%), and poor visual behavior (n=9; 36.0%). CONCLUSION: In children with optic pathway tumors who were unable to perform recognition acuity tests, it was possible to quantify visual impairment by sweep-visually evoked potentials and to evaluate interocular differences in acuity. The severity of age-based grating visual acuity deficit and interocular differences was in accordance with ophthalmological abnormalities and neuroimaging results. Grating visual acuity deficit is useful for characterizing visual status in children with optic pathway tumors and for supporting neuro-oncologic management.

Visual outcomes of audio-luminous biofeedback training for a child with idiopathic nystagmus.

Microperimetry biofeedback training is a vision rehabilitation method that involves the training of attention and oculomotor control, and the rehabilitation of poorly located and non-functional preferred retinal loci. It can significantly improve distance and near visual acuity in age-related macular degeneration. Previous studies have shown that biofeedback training using electrical nystagmography can reduce nystagmus amplitude and increase foveation time. However, these improvements have not been sustained following training sessions. We hereby report a pediatric case of idiopathic nystagmus in an 11-year old patient treated with microperimetric biofeedback to improve visual acuity and fixation stability. The training had a beneficial impact, positively affecting fixation stability as well as distance and near reading vision. Subjectively, improvement in quality of life was also reported. Conversely to previous studies, the positive effects in this case were maintained for as long as twelve months following therapy. To the best of our knowledge, this is the first case with long-term benefits to be reported in the literature.

Principal Cause of Poor Visual Acuity after Neovascular Age-Related Macular Degeneration: Age-Related Eye Disease Study 2 Report Number 23.

PURPOSE: To analyze the principal cause for poor vision in eyes with best-corrected visual acuity (BCVA) of 20/200 or worse 2 years after neovascular age-related macular degeneration (nAMD). DESIGN: Prospective cohort study of participants enrolled in a clinical trial of oral supplements. PARTICIPANTS: Age-Related Eye Disease Study 2 (AREDS2) participants whose eyes began anti-vascular endothelial growth factor (VEGF) therapy for incident nAMD and had data available at 2 years. METHODS: Participants underwent refracted BCVA testing, ophthalmoscopic examination, and fundus photography at baseline and annual visits. Self-reports of anti-VEGF injections were collected. MAIN OUTCOME MEASURES: Principal cause of BCVA of 20/200 or worse at 2 years, detected on fundus photography grading. RESULTS: Of the 594 eligible eyes, the number with BCVA of 20/200 or worse at 2 years was 56 (9.4%). Mean BCVA was 14.9 letters (standard deviation [SD], 12.3 letters; Snellen equivalent, 20/500), versus 70.1 letters (SD, 12.8 letters; Snellen equivalent, 20/40) in the other group. Of the 55 eyes with fundus photography available at 2 years, 33 (60.0%) had central macular atrophy and 22 (40.0%) had central subretinal fibrosis assessed as the principal cause for poor vision. The group with poor BCVA had a higher proportion of non-White participants (8.9% vs. 1.7%; P = 0.006), lower BCVA 2 years earlier (mean, 38.0 letters [SD, 26.7 letters; Snellen equivalent, 20/160] vs. 71.8 letters (SD, 11.9 letters; Snellen equivalent, 20/40]; P < 0.0001), higher proportion with macular atrophy 2 years earlier (26.8% vs. 12.3%; P = 0.003), higher proportion with macular hemorrhage (25.5% vs. 13.2%; P = 0.014), and fewer anti-VEGF injections (7.6 vs. 10.2; P = 0.001). CONCLUSIONS: Visual acuity data and fundus photography were obtained in a clinical trial environment, but were related to anti-VEGF therapy given in routine clinical practice. At 2 years after starting anti-VEGF therapy, almost 1 in 10 eyes showed BCVA at the level of legal blindness. From fundus photography grading, the cause of poor vision appeared to be macular atrophy in 60% and subretinal fibrosis in 40%. These data may be useful in understanding the long-term limits to good vision in nAMD.

Effectiveness of Low Vision Rehabilitation Using Microperimetric Acoustic Biofeedback Training in Patients with Central Scotoma.

PURPOSE: To evaluate the efficacy of visual rehabilitation with microperimeter biofeedback in patients with central scotoma. MATERIALS AND METHODS: 35 consecutive patients with central scotoma (17 age-related macular degeneration (AMD), 14 Stargardt disease, and 4 cone dystrophy) were included in the study. Visual acuity, reading performance by Minnesota Low Vision Reading Test (MNREAD), quality of life by 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), and fixation analysis by MAIA microperimeter were evaluated before and 1 month after training. The rehabilitation program consisted of 10 training sessions of 10 minutes. RESULTS: The median best-corrected visual acuity (BCVA) was 0.80 logMAR (range 0.3 to 1.3 logMAR). Fifty-nine percent of patients with AMD developed a preferred retinal locus (PRL) nasal to the fovea, and 64% of the patients with Stargardt disease preferred a PRL superior to the fovea. The PRL location in 3 of 4 cone dystrophy patients was nasal to the fovea. The mean PRL distance from the fovea was 7.57 ± 3.61 degrees. Fixation stability improved with P1 values of 22.34 ± 11.81 versus 32.05 ± 18.79 (p = .003) and 95% bivariate contour ellipse area (BCEA) values of 41.6 versus 23.6 (p = .018) before and after training, respectively. There was a significant difference in reading acuity between before and after training (p = 0.008). The overall score and near activities score of NEI VFQ-25 were found to be increased at the end of the rehabilitation (p < 0.001). CONCLUSION: Rehabilitation with acoustic biofeedback in patients with central scotoma looks like a useful technique for improving fixation stability, reading performance and quality of life.

Low-Intensity Laser Light Projection for Improved Reading Abilities in Low-Vision Patients.

PURPOSE: To evaluate the efficacy of a new laser imaging device that projects images onto functioning macular areas, to improve visual acuity (VA) in low-vision patients with macular diseases. METHODS: An interventional case series of consecutive patients with low vision in their right eyes (RE). RE VA was measured by showing the patients digits of various standard sizes and measuring their best-corrected VA (BCVA). Then, using the I.C.INSIDE device to project the same standard digits onto functioning macular areas. Patient's ability to recognize the digits with the I.C.INSIDE device was correlated with patient's performance using telescopic low-vision aids. The main outcome measure was change in VA with the different visual aids. RESULTS: Eleven patients (6 males and 5 females) with an average age of 75 ± 6.7 years and low vision in their RE due to macular diseases were included in the study. Baseline BCVA was 1.554 ± 0.50 logMAR. Low-vision aids improved mean VA in 10 patients to 0.64 ± 0.40 logMAR (p < .0001), further improvement was noticed in 8 patients to 0.35 ± 0.16 logMAR (p < .0001) using the laser device, but, three patients did not recognize any digit using the laser device. CONCLUSIONS: The I.C.INSIDE device significantly improved baseline VA in low-vision patients with macular diseases, using extra-foveal fixation.

The efficacy of biofeedback visual rehabilitation therapy in patients with infantile nystagmus syndrome: A retrospective study.

OBJECTIVE: To report fixation stability changes in patients with different forms of infantile nystagmus syndrome (INS), who have undergone a visual rehabilitation through biofeedback fixation training (BFT) with microperimetry (MP). DESIGN: Retrospective study. METHODS: Patients 6 to 12 years-old with INS who performed BFT with MP. Initially 10 once-weekly followed by eight twice-weekly sessions of BFT during a minimum of 6 months period were performed. Visual acuity (VA) and MP fixation stability indices were analyzed, including displacement from fixation point (P1, P2) and percentage of retinal loci used during fixation attempt (BCEA 63% and 95%). Statistical analysis was conducted at baseline (BL), 10 weeks (W10) and 6 months (M6). RESULTS: Twelve patients (mean age 8.9 years.) with INS completed the whole training session. All patients showed significant improvement in the mean BCEA fixation area (deg2): For BCEA@95% BL was 78.0, 46.1 at W10, and 27.4 at M6 (p-value = 0.004). For BCEA@63% BL was 27.3, 15.4 in W10, and 9.17 at M6 (p = 0.01). The ANOVA test for the FS indices of P1 and P2, as well as for BCVA showed no significant difference when compared at the same intervals. CONCLUSION: Fixation stability (FS) indices of BCEAs (63% and 95%) improved at W10 and M6, while P1 and P2 showed significant improvement at W10 but not at M6, probably because BCEA involves a much larger area than P1 and P2. VA did not show significant improvement at any time point.

Efficacy of biofeedback rehabilitation based on visual evoked potentials analysis in patients with advanced age-related macular degeneration.

Age-related macular degeneration (AMD) is a progressive and degenerative disorder of the macula. In advanced stages, it is characterized by the formation of areas of geographic atrophy or fibrous scars in the central macula, which determines irreversible loss of central vision. These patients can benefit from visual rehabilitation programmes with acoustic "biofeedback" mechanisms that can instruct the patient to move fixation from the central degenerated macular area to an adjacent healthy area, with a reorganization of the primary visual cortex. In this prospective, comparative, non-randomized study we evaluated the efficacy of visual rehabilitation with an innovative acoustic biofeedback training system based on visual evoked potentials (VEP) real-time examination (Retimax Vision Trainer, CSO, Florence), in a series of patients with advanced AMD compared to a control group. Patients undergoing training were subjected to ten consecutive visual training sessions of 10 min each, performed twice a week. Patients in the control group did not receive any training. VEP biofeedback rehabilitation seems to improve visual acuity, reading performances, contrast sensitivity, retinal fixation and sensitivity and quality of life in AMD patients.

Case Report: Nutritional and Toxic Optic Neuropathy: A Diagnostic Dilemma.

SIGNIFICANCE: Nutritional and toxic optic neuropathies are rare disorders characterized by visual impairment due to optic nerve damage by a toxin, usually with coexisting nutritional deficiencies. Its pathophysiology is still unclear, and multiple mechanisms implicated act synergistically to bring about this condition. The decline in its incidence and its confusing clinical appearance make diagnosing nutritional and toxic optic neuropathies challenging. PURPOSE: This is an observational clinical case report of an atypical clinical case of a nutritional and toxic optic neuropathy with a subacute presentation and papilledema at the time of diagnosis. The patient provided written informed consent for medical information and images to be published. CASE REPORT: A 47-year-old man presented with progressive, painless bilateral decrease in central vision over 15 days. The patient had a long-standing history of alcohol abuse and was a heavy smoker. The examination revealed dyschromatopsia, 20/400 visual acuity on both eyes, and no relative afferent pupillary defect. Funduscopy revealed bilateral papilledema. A visual field test showed generalized depression with centrocecal involvement in the left eye. Laboratory studies evidenced decreased vitamin B12/B1 and red blood cell folate levels, increased acute phase reactants, hypertransaminasemia, and macrocytic anemia. Serologies and methanol in urine were negative. After the discontinuation of tobacco use and alcohol accompanied by vitamin supplementation, our patient's visual field, visual acuity, and papilledema improved remarkably. After 5 months, visual acuity and funduscopy were normal. CONCLUSIONS: Although some hallmark signs were visible in this case, its subacute presentation and the presence of papilledema at diagnosis caused some diagnostic uncertainty. Nutritional and toxic optic neuropathy is a rare and challenging diagnosis because of a lack of biomarkers. Eye care clinicians should consider nutritional and toxic optic neuropathies to prevent severe and irreversible visual damage resulting from underdiagnosis and mismanagement.

Biofeedback Low Vision Rehabilitation with Retimax Vision Trainer in Patients with Advanced Age-related Macular Degeneration: A Pilot Study.

PURPOSE: To evaluate the effectiveness of Visual Evoked Potential (VEP) biofeedback rehabilitation in selected low vision patients with advanced age-related macular degeneration (AMD). DESIGN: Retrospective observational cohort study. METHODS: Patients affected by advanced AMD, central macular atrophy with unstable fixation and best corrected visual acuity (BCVA) between 20/100 and 20/320 were considered. Selected patients underwent fundus photography and microperimetry with fixation analysis for the selected eye (highest BCVA). Ten consecutive training sessions of 10 min each were performed twice a week in the selected eye with Retimax Vision Trainer (CSO, Florence). BCVA, reading acuity and reading speed, contrast sensitivity, fixation, retinal sensitivity and quality of life questionnaire (VFQ-25) were evaluated at baseline and 7 days following the final session. RESULTS: Significant improvements in terms of BCVA [p = .011], reading speed [p = .007], VFQ-25 score [p = .007], retinal sensitivity [p = .021] and fixation stability in the central 2° and 4° [p = .048; p = .037] post-treatment were observed for the 9 patients enrolled, with insignificant improvements observed in reading acuity and contrast sensitivity [p = .335; p = .291]. CONCLUSIONS: Preliminary results support VEP biofeedback rehabilitation improvements for visual function and quality of life in advanced AMD patients with low vision.