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.

Efficacy and Patients' Satisfaction with the ORCAM MyEye Device Among Visually Impaired People: A Multicenter Study.

To evaluate usability of and satisfaction with OrCam MyEye, a finger-size wearable assistive technology device for visually impaired during real-world tasks. This prospective multicenter study was conducted on visually impaired people recruited from 5 vision rehabilitation centers. Patients performed real-world tasks such as near and distance reading, money handling, colour identification and face recognition in 2 different scenarios: without using any low vision aid and with OrCam. System Usability Scale (SUS), Patient's Global Impression of Change (PGIC), the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) and the Psychosocial Impact of Assistive Devices Scale (PIADS) were administered after the use of the OrCam device. Among the 100 participants, use of OrCam MyEye device improved many daily-living tasks (F = 1.67, P < .05), and in particular reading and face recognition. Multivariate logistic regression showed that age and visual field defect explained 89% of the variation in efficacy of the device. Nearly half (45%) of the participants indicated a positive rating with the SUS. The PGIC rates showed a minimal improvement with a mean score of 4.2 (SD:1.8). The most highlighted parameter with the QUEST 2.0 test was "ease of use" in 58% (48 subjects). The PIADS indicator showed that the device positively impacted on the daily-living tasks of users (r2 = 0.72, P < .05). Regression modelling demonstrated a good relation between the questionnaires scores and demographic, disease and visual factors (P < .05). OrCam MyEye allowed visually impaired people to read, handle money and face recognition independently. This device may offer to these subjects to be independent.

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.

Reading with central vision loss: binocular summation and inhibition.

PURPOSE: There are conflicting reports as to whether there is a binocular advantage or disadvantage when reading with central vision loss. This study examined binocular reading summation in patients with macular degeneration. METHODS: Seventy-one patients with bilateral central vision loss [mean age: 63 (S.D. = 21) years] participated. Reading performances during binocular and monocular viewing with the better eye (i.e., the eye with the best monocular visual acuity) were evaluated using different versions of the Italian MNREAD reading chart (www.precision-vision.com). Fixation stability and preferred retinal loci (PRLs) were recorded monocularly for each eye. The overall sample was split into inhibition, equality, and summation groups based on the binocular ratio (i.e., binocular/monocular) of the maximum reading speed. RESULTS: 41% of patients experienced binocular inhibition, 42% summation, and 17% equality. Binocular reading speed of the inhibition group was approximately 30 words per minute slower than those of the equality and summation groups, although the inhibition group had the best visual acuity. These patients generally had monocular PRLs in non-corresponding locations temporal or nasal to the scotoma, had the largest interocular acuity difference and lacked residual stereopsis. The three groups did not differ in fixational control, contrast sensitivity or critical print size. CONCLUSIONS: Equal proportions of patients with central vision loss show binocular reading summation and inhibition. Patients with binocular reading inhibition have poorer reading performance and different clinical characteristics than those with binocular reading summation and equality.

Use of the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) questionnaires for clinical decision-making and psychological referral in ophthalmic care: a multicentre observational study.

OBJECTIVES: The aim of this study was to evaluate the influence of anxiety and depression on clinician decision-making in patients suffering from chronic eye disease in ophthalmological clinical practice. DESIGN AND SETTING: This multicentre observational study, in collaboration with the WHO, included ophthalmologists and their patients affected by chronic eye disease. States of anxiety and depression were screened with specific questionnaires, the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), self-administered by patients before the visit. In the present analysis, we report data from three major eye care centres in Italy between 2021 and 2022. PRIMARY AND SECONDARY OUTCOMES: To assess self-reported changes in ophthalmologists' clinical approach (communication style and their clinical-therapeutic strategies) and decisions after knowing questionnaire scores (primary aim), and to analyse the PHQ-9 and GAD-7 scores in patients with chronic eye diseases (secondary aim). RESULTS: 41 ophthalmologists and 359 patients were included. The results from PHQ-9 and GAD-7 scores showed critical depression and anxiety status scores (PHQ-9 ≥5 and GAD-7 ≥10) in 258 patients. In 74% of cases, no actions were taken by the ophthalmologists based on these scores; in 26% of cases, they changed their clinical approach; and in 14% of cases, they referred the patients for psychological/psychiatric evaluation. CONCLUSIONS: States of anxiety and depression affect many patients with chronic eye conditions and need to be detected and managed early to improve patients' well-being. Providing ophthalmologists with knowledge of their patients' psychological conditions can change the clinical management and attitude towards referral for a psychological evaluation. Further studies are needed to expand our knowledge of how to raise awareness among ophthalmologists regarding multimorbidity of patients suffering from chronic eye diseases in order to achieve better clinical outcomes.

Utility values and electronic device use in low-vision people attending rehabilitation services: Data from a nation-wide registry in Italy.

PURPOSE: To estimate utility values associated with visual loss using EuroQol (EQ-5D) questionnaire, the impact of low-vision (LV) device use on utilities and the contribution of Instrumental Activities of Daily Living (IADL) score in patients attending vision rehabilitation (VR) services enrolled in the Italian Device & Aids Register (D.A.Re). METHODS: This is a multicenter, prospective, cross-sectional study. D.A.Re. collects general and clinical information, vision-specific variables, use of electronic devices and quality of life questionnaires. RESULTS: A total of 442 patients (75.0±16.6 years, 275 female) were included, 88 (19.9%) used specialised electronic LV devices, and 116 (26.2%) used smartphones and tablets. Users of smartphones and tablets were younger than non-users (67.5 vs. 77.6 years, p<0.001), but overall, their age ranged between 20 and 93. Stronger associations were found between vision-specific variables and IADL score compared to EQ-5D score. In multivariable age-adjusted models, the utility value of using smartphones and tablets on EQ-5D score was 0.12 (p<0.01), slightly larger than that of 1.0 logMAR difference (-0.09, p<0.01) or visual field damage within 10° of fixation (-0.10, p<0.01). Use of portable low-vision electronic devices and being employed or student (vs. retired) was also associated with better utility values (0.12 and 0.15, respectively, p<0.05). CONCLUSIONS: Visual loss is associated with loss of utilities in Italian patients attending VR services, whereas special-purpose electronic aids, and smartphone and tablet use are associated with better utility values. We found that IADL may be more sensitive to visual loss than EQ-5D and could be a valid health-related quality of life outcome in trials on VR.

Relationship between fixation stability measured with MP-1 and reading performance.

BACKGROUND: People with visual impairment have reduced reading performance, which is thought to be related to unstable or eccentric fixation. New microperimeters such as the MP-1 offer straightforward analysis of fixation stability. The aim of this study was to investigate the relationship between fixation stability and reading speed in a large cohort of people with diverse causes of visual impairment and to verify the correlation between reading speed and different methods for the quantification of fixation. METHODS: The better eye of one hundred and twenty subjects was assessed. Fixation values were obtained from the MP-1 microperimeter. Reading speed was evaluated using newspaper text with magnifiers if required. RESULTS: The poorest fixation stability and reading performance was found in people with age-related macular degeneration while the best fixation was in retinitis pigmentosa subjects. A linear relationship was found between reading speed and the proportion of fixations within 2° (r² = 0.51, p < 0.001) and 4° (r² = 0.36, p < 0.001). A negative correlation was found between reading speed and all three bivariate contour ellipse areas (BCEA; for log transformation of 1-S.D., 2-S.D. and 3-S.D.: r² = 0.39, p < 0.001). In a multiple regression model, proportion of points falling within 2° and 4° circle was significantly related to reading speed (r² = 0.55, p < 0.01; r² = 0.43 p < 0.01); also BCEAs values were strongly related to reading ability only in patients with central vision loss (r² = 0.62, p < 0.01 for LogBCEA 68.2%; r² = 0.61, p < 0.01 for LogBCEA 95.4% and 99.6%) and peripheral defect (r² = 0.52, p < 0.01 for LogBCEA 68.2%; r² = 0.50, p < 0.01 for LogBCEA 95.4%; r² = 0.49, p < 0.01 for LogBCEA 99.6%) but not in combined defect subjects. CONCLUSIONS: The study confirms that in people with visual impairment the reduced reading performance is correlated with fixation instability. Moreover, there is a strong relationship between reading speed and both the proportion of fixations falling within 2° and 4° and bivariate contour ellipse area values.

Use of electronic devices by people attending vision rehabilitation services in Italy: A study based on the device and aids registry (D.A.Re).

PURPOSE: To investigate the characteristics of electronic device users, specifically smartphones and tablets, in the Device & Aids Register (D.A.Re), from several low-vision rehabilitation services in Italy. METHODS: We collected general and clinical information about ocular and systemic diseases, visual function, reading speed and Instrumental Activities of Daily Living (IADL) questionnaire score. Technological details of each optical and electronic device, (including screen size, touch-screen and OCR functions, text-to-speech function) were also collected. RESULTS: 1218 patients (752 females and 466 males) were included in our analysis, mean age 71.5 (±18.8) years. Users of electronic aids (n.237) were slightly younger (67 vs 72 years, p < 0.001) than non-users (n.981), had a worse reading speed (38 vs 65 words/minute), critical print size (43 vs 28 print size, p < 0.001), poorer visual acuity (VA)(1.0 logMAR or less: 30% non-users vs 73% users, p < 0.001) and more commonly visual field restriction within 10° (23% vs 14%, p = 0.001). A similar proportion of users and non-users were retired (about 70%) and about 16-17% were employed. The use of portable electronic devices (5″or less, p < 0.001; 6″ to 18″ screen size, p = 0.017) was associated with better IADL scores, and the use of stand devices with worse IADL score (p < 0.001); Furthermore, using smartphones and tablets (193 subjects) was strongly associated with better IADL scores. CONCLUSION: We found that using electronic devices, and especially smartphone and tablets, were associated with better vision-related quality of life in low-vision people attending rehabilitation services. While this association does not mean causality, these findings seemed robust to confounder adjustment.

Visual Function in Children with GNAO1-Related Encephalopathy.

BACKGROUND: GNAO1-related encephalopathies include a broad spectrum of developmental disorders caused by de novo heterozygous mutations in the GNAO1 gene, encoding the G (o) subunit α of G-proteins. These conditions are characterized by epilepsy, movement disorders and developmental impairment, in combination or as isolated features. OBJECTIVE: This study aimed at describing the profile of neurovisual competences in children with GNAO1 deficiency to better characterize the phenotype of the disease spectrum. METHODS: Four male and three female patients with confirmed genetic diagnosis underwent neurological examination, visual function assessment, and neurovisual and ophthalmological evaluation. Present clinical history of epilepsy and movement disorders, and neuroimaging findings were also evaluated. RESULTS: The assessment revealed two trends in visual development. Some aspects of visual function, such as discrimination and perception of distance, depth and volume, appeared to be impaired at all ages, with no sign of improvement. Other aspects, reliant on temporal lobe competences (ventral stream) and more related to object-face exploration, recognition and environmental control, appeared to be preserved and improved with age. SIGNIFICANCE: Visual function is often impaired, with patterns of visual impairment affecting the ventral stream less.

Economic Aspects in the Management of Diabetic Macular Edema in Italy.

Background: Diabetic Macular Edema (DME) is the most common cause of vision loss in diabetic patients. Currently, the Vascular Endothelial Growth Factor inhibitors (anti-VEGFs) are used as the first line of DME treatment and corticosteroid implants are usually used as a second-line treatment. These implants are a safe and effective therapeutic option that can improve the quality of life of DME patients by reducing the intravitreal injections number. We determined the economic impact related to DME, also from the social perspective, and the consequences of the increased use of the dexamethasone implant. Methods: The analysis compares two scenarios: the first based on the current rate of recourse to the therapeutic alternatives available in the Italian healthcare setting (as is) and the second based on the assumption of an increased recourse to dexamethasone implants (to be). The results are expressed both in terms of the resource absorption associated with the two scenarios and in terms of the cost differential yielded by their comparison. Results: The increased use of the dexamethasone implant allows considerable savings in terms of healthcare professionals' time, follow-up and productivity lost by patients/caregivers. These savings would reduce healthcare costs for the management of DME patients in Italy by €2,058,238 in 5 years. Conclusions: To optimize the healthcare resources allocation, it is necessary to implement treatments that yield not only cost reductions but also a clinical benefit for patients. The dexamethasone implant use is an example of DME management that generates value for patients, health system and society.

Posturographic Analysis in Patients Affected by Central and Peripheral Visual Impairment.

Although vision loss is known to affect equilibrium maintenance, postural control in patients affected by low vision has been poorly investigated. We evaluated postural stability and the ability to use visual, proprioceptive and vestibular information in different low vision patterns. Ten adults with normal vision (NC), fourteen adults affected by central visual impairment (CLV) and eight adults affected by peripheral visual impairment (PLV) were enrolled in our study. Patients underwent visual, vestibular and postural evaluation (bedside examination, Computed Dynamic Posturograophy). Motor Control Tests were performed to analyze automatic postural adaptive responses elicited by unexpected postural disturbances. Clinical evaluations did not show abnormality in all patients. In the Sensory Organization Test, CLV and PLV patients performed more poorly in conditions 3-6 and 3-4, as compared to NC subjects. The condition 5 score was significantly lower in the CLV group with respect to the PLV patients. Composite equilibrium scores demonstrated significant differences between low-vision subjects vs. NC subjects. No differences were found for somatosensorial contribution. Visual afferences showed lower values in all visually impaired subjects, while vestibular contribution was lower in the CLV patients as compared to the NC and PLV patients. MCT latencies were significantly worse in the CLV subjects. In the low-vision patients, postural control was modified with a specific pattern of strategy adaptation. Different modulations of postural control and different adaptive responses seemed to characterize CLV patients as compared to PLV subjects.

Cortical Visual Impairment in CDKL5 Deficiency Disorder.

BACKGROUND: CDKL5 deficiency disorder (CDD) is a developmental encephalopathy caused by pathogenic variants in the gene cyclin-dependent kinase-like 5. Cerebral visual impairment (CVI) is frequent in patients with CDD. In addition to being recognized as a specific feature of the pathology, it has been suggested that visual impairment may correlate with neurodevelopmental outcome and epilepsy severity, but no systematic behavioral visual assessment has been performed. The aim of our study was to evaluate clinical and electrophysiological profile of CVI in patients with CDD, to correlate various aspects of visual function to neurodevelopmental and epileptic features. METHODS: The study included all patients with CDD from the National Pathology Registry. All patients underwent neurological examination, a disease-specific functional assessment, structured clinical evaluation of visual functions, including pattern reversal visual evoked potential (VEP), and a detailed monitoring of epileptic features, including video-EEG. RESULTS: All the 11 patients recorded in the CDKL5 national registry, 10 females and one male, age range of 1.5 to 24 years (mean 9, SD 7.7, median 6.5), were enrolled. Visual function is impaired in all patients; in particular, visual fields, visual acuity, contrast sensitivity, and stereopsis were consistently abnormal whereas other aspects, such as fixing and tracking, were relatively preserved. Pattern reversal VEP was abnormal in nearly 80% of our patients. No correlation was found among CVI severity, age, level of psychomotor development, EEG abnormalities, and pathology stages even if an overall less abnormal EEG pattern was more often associated with better visual results. CONCLUSION: In conclusion, CVI can be considered as a major feature of CDD with a diffuse involvement in several behavioral and electrophysiological aspects. Larger cohorts will help to better clarify the possible prognostic role of EEG severity in predicting both visual and developmental abnormalities.

Visual Function and Ophthalmological Findings in CHARGE Syndrome: Revision of Literature, Definition of a New Clinical Spectrum and Genotype Phenotype Correlation.

CHARGE syndrome (CS) is a rare genetic disease causing multiple anatomical defects and sensory impairment. Visual function is usually reported by caregivers and has never been described with a structured behavioral assessment. Our primary objective was to describe ocular abnormalities, visual function and genotype-ocular-phenotype correlation in CS. A prospective monocentric cohort study was performed on 14 children with CS carrying pathogenic CHD7 variants. All children underwent ophthalmological evaluation and structured behavioral assessment of visual function. The VISIOCHARGE questionnaire was administered to parents. Colobomas were present in 93% of patients. Genotype-phenotype correlation documented mitigated features in a subset of patients with intronic pathogenic variants predicted to affect transcript processing, and severe features in patients with frameshift/nonsense variants predicting protein truncation at the N-terminus. Abnormal visual function was present in all subjects, with different degrees of impairment. A significant correlation was found between visual function and age at assessment (p-value = 0.025). The present data are the first to characterize visual function in CS patients. They suggest that hypomorphic variants might be associated with milder features, and that visual function appears to be related to age. While studies with larger cohorts are required for confirmation, our data indicate that experience appears to influence everyday use of visual function more than ocular abnormalities do.

A New System for Assessing Visual Disability Using a Digital Visor.

BACKGROUND: Considering the lack of universally accepted visual requirements for driving and for defining various grades of visual disability, the aim of this study is to propose a new method that provides a numerical score resulting from a combined assessment of the visual field and visual acuity loss obtained using a digital technology visor. METHODS: This study presents a new system for calculating the percentage of visual disability by combining binocular visual acuity and binocular visual field assessments. A new Global Vision Evaluation System digital technology visor uses standardized, reproducible criteria to produce well-defined, numerically expressed test results. Through a specific algorithm, the device produces a numerical value expressing the percentage of visual disability. RESULTS: Eighty-six subjects with various types of visual impairment underwent visual acuity and visual field test examinations carried out employing both traditional methods and the new digital visor. The two methods provided homogeneously similar results regarding the positioning of the subjects on the visual disability scale. CONCLUSIONS: The new digital visor seems to be a valid method to ensure that visual disability assessments are more homogeneous and reliable, and that, consequently, the resources available for this purpose are more fairly distributed.

The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 (VA LV VFQ-48): Performance of the Italian version.

PURPOSE: The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 is among the most validated tools to collect patient-reported outcomes in a low-vision population. We have aimed to conduct a pilot validation of the Italian version of the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48. METHODS: The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 was translated using a standardized procedure and then administered to consecutive low-vision patients attending rehabilitation services in three centers. Patients were interviewed by a trained psychologist regarding the individual items of the tool. RESULTS: We included 131 patients with a mean visual acuity of 0.91 logMAR (standard deviation: 0.42 logMAR), mostly affected by age-related macular degeneration. The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 showed high internal consistency (Cronbach's alpha: 0.98) and good item-test and item-rest correlation (median: 0.73 and 0.71, respectively). Both the overall score and the subscale (reading, visual motor, mobility and visual information) scores significantly correlated with visual acuity, reading acuity and speed. Reading speed achieved the best absolute correlation with the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 scores (Spearman r: 0.39-0.49). CONCLUSION: The Italian version of the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 is a valid tool to assess patients attending low-vision services. Revising a few items may further improve the tool.

Perceptual learning in patients with Stargardt disease.

OBJECTIVE: To evaluate the efficacy of Perceptual Learning in improving the peripheral reading performance of patients with Stargardt disease (STGD). DESIGN: Prospective observational randomized study. PARTICIPANTS: Fourteen consecutive patients (7 females, 7 males; median age of 50.4 ± 12.8 years) with STGD were analyzed and divided into two groups: Group A received "Win-flash" as Perceptual Learning training and Group B was used as control. METHODS: Subjects underwent an ophthalmic evaluation at baseline, after perceptual learning training and at 6 months of follow-up. Outcomes measured included reading speed, contrast sensitivity and fixation stability. RESULTS: Reading speed improved of 51,7% after training in group A. Visual acuity, contrast sensitivity and fixation stability enhanced in group A after training from 0.89 (±0.09) LogMAR to 0.75 (±0.2) LogMAR (t(6)= 3.6, p= 0.001), from 0.8 (±0.3) LogC (0.6 - 0.9) to 1.3 (±0.3) LogC (t(13)=3.17, p= 0.003) and from 59.3 % (± 24.3) to 71.5 % (± 20.4) (t(13)=1.8 p= 0.04), respectively. No changes were found in group B. At 6-monts of follow-up, visual acuity and contrast sensitivity decreased in group A. CONCLUSIONS: STGD patients receiving "Win-flash training", as PL technique, showed an improvement of reading performance on a real-world task. Early follow-up for perceptual learning re-intervention should be considered.

Correlation between Choriocapillaris Density and Retinal Sensitivity in Stargardt Disease.

The aim of this work was to characterize the choriocapillaris (CC) in patients with Stargardt disease (STGD) using the swept source widefield optical coherence tomography angiography (SS WF OCTA) and to compare CC perfusion density to retinal sensitivity, analyzed using microperimetry (MP). This cross-sectional study included 9 patients (18 eyes) with STGD and central CC atrophy (stage 3 STGD). The CC was analyzed using SS WF OCTA and areas of different CC impairment were quantified and correlated with retinal sensitivity analyzed using MP. The main outcome measures were the percent perfused choriocapillaris area (PPCA), retinal sensitivity, and correlation between PPCA and retinal sensitivity. Seventeen eyes of 9 patients suffering from stage 3 STGD were analyzed. SS WF OCTA revealed a vascular rarefaction in central atrophic zones and a near atrophy halo of choriocapillaris impairment. In all eyes were noticed a central atrophy (CA) area with absolute absence of CC that corresponded to 0 dB points at MP, a near atrophy (NA) zone of PPCA impairment that included points with decreased sensitivity at MP and a distant from atrophy (DA) zone with higher PPCA and retinal sensitivity values. The mean difference of PPCA and retinal sensitivity between NA and CA and DA and CA was statistical significantly different (p < 0.01), the latter showing higher values. A direct relationship between PPCA and retinal sensitivity was found (p < 0.001). Choriocapillaris damage evaluated using SS WF OCTA correlates with MP, these data suggest that CC impairment may be a predictor of retinal function in patients with STGD.

Morpho-functional analysis of Stargardt Disease for reading.

OBJECTIVE: To analyze Stargardt disease (STGD) by morpho-functional examination and investigate the relationship between morpho-functional measures and reading performance. DESIGN: Observational case series study. PARTICIPANTS: Fifteen patients with STGD. METHODS: Twenty-six eyes of 15 patients underwent complete ophthalmic evaluation. Spectral domain optical coherence tomography, fundus autofluorescence (FAF), best corrected visual acuity (BCVA), and microperimetric examinations were performed. FAF and optical coherence tomography (OCT) overlap on microperimetric images was obtained in order to evaluate both tomographic and FAF features passing through the eccentric fixation area. Both morphologic features and functional data were correlated with magnification of prescribed device and reading rate. RESULTS: Univariable analysis showed a significant correlation between magnification power and greatest linear dimension of both OCT and FAF (r = 0.69 and r = 0.67; p < 0.05). Magnification power was related to best corrected visual acuity (r = 0.56; p < 0.05). Retinal sensitivity map (r = 0.57; p < 0.05) was considered an indicator of reading rate. Magnification levels showed a positive correlation with eccentric preferred retinal location (p = 0.03) and the degree of FAF alteration (normal, dishomogeneous, ipoautofluorescence; p < 0.0001). CONCLUSIONS: As a result of the overlapping of OCT/FAF imaging on microperimetric exam, residual activity of outer retinal layers passing through the eccentric fixation area seems to be related with required magnification and reading rate. Identification of morpho-functional parameters is helpful for designing a customized rehabilitative program.

Bernhard Sabel and 'Residual Vision Activation Theory': a History Spanning Three Decades.

This review has the purpose of retracing the work of Professor Bernard Sabel and his group over the last 2-3 decades, in order to understand how they achieved formulation of the 'Residual Vision Activation Theory'. The methodology proposed is described, from the first studies in 1995 with High Resolution Perimetry requiring a six-months training period, to the new technologies, such as repetitive transorbital Alternating Current Stimulation, that require ten days of training. Vision restoration therapy has shown improvement in visual responses irrespective of age at the training, lesion aetiology and site of lesion. The hypothesis that visual training may induce network plasticity, improving neuronal networks in cortical and subcortical areas of both hemispheres, appears to be confirmed by recent studies including observation of the cerebral activity by fMRI and EEG. However, the results are quite variable and the mechanisms that influence cerebral activity are still unclear. The residual vision activation theory has been much criticized, both for its methodology and analysis of the results, but it gave a new impulse to the research in this area, stimulating more studies on induced cerebral plasticity.