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

Impact of visual function on computer task accuracy and reaction time in a cohort of patients with age-related macular degeneration

Older individuals with macular diseases, such as age-related macular degeneration, experience central vision loss (CVL) due to degeneration of their photoreceptors and retinal cells. Patients with CVL may experience various vision impairments, including of visual acuity, fixation stability, contrast sensitivity, and stereoacuity. After CVL, most patients develop a preferred retinal locus outside the affected macular region, which serves as a new visual reference. In this review, we provide an overview of the visual function and impairment in individuals with CVL. In addition, the important role of biofeedback training on the visual function and activity of individuals with CVL is also reviewed. Accordingly, the location and development of the preferred retinal loci are discussed. Finally, this review discusses how to conduct biofeedback training to treat individuals with CVL.

PurposeTo compare progressive changes in visual function parameters in patients with Fuchs entothelial dystrophy (FED) who underwent Descemet Membrane Endothelial Keratoplasty (DMEK). To compare visual results after DMEK with visual function parameters in healthy subjects without corneal pathology.MethodsThirty patients (30 eyes) with FED who underwent DMEK surgery were included in the study. All subjects underwent best corrected visual acuity (BCVA) evaluation using the ETDRS optotype in photopic and scotopic conditions, and contrast sensitivity (CS) assessment using the CSV 1000 and the Pelli Robson test in different lighting conditions, preoperatively, at 1 and 6 months after surgery. Thirty eyes of 30 healthy controls were evaluated using the same protocol and compared with the patients’ final postsurgery data.ResultsA significant improvement in all visual function parameters was observed in patients 1 month (p < 0.05) and 6 months (p < 0.05) after DMEK, compared with preoperative levels. No significant differences were observed between patients and healthy controls in the lowest spatial frequency of 3cpd (photopic, p = 0.891; mesopic, p = 0.064; mesopic with glare, p = 0.786). Healthy controls had significantly higher BCVA in photopic and scotopic conditions (p = 0.015, p = 0.03, respectively), better CS measured with the CSV 1000 test in the spatial frequencies of 6 cpd, 12 cpd and 18 cpd and with the Pelli Robson test (p = 0.002).ConclusionsDMEK improves visual function parameters in patients with FED in the first month after surgery. Patients who underwent DMEK present similar contrast sensitivity to healthy subjects in lower frequencies. However, the rest of the values assessed were significantly lower in DMEK patients compared to healthy controls 6 months after surgery.

Learning effects of dynamic postural control by auditory biofeedback versus visual biofeedback training

PurposeScotopic microperimetry measures retinal sensitivity under very low light and may be useful in conditions characterized by nyctalopia, such as retinitis pigmentosa and age-related macular degeneration. The Scotopic Macular Integrity Assessment device enables two-color perimetry to isolate rod and cone responses. This study assesses the reliability, test–retest repeatability, and sensitivity in healthy participants aiming to establish normative values.MethodsScotopic microperimetry was performed using cyan and red stimuli on a 37-point radial grid after dark adaptation on control participants with no history of eye disease and visual acuity of 0.1 logarithm of the minimum angle of resolution or better. Fixation stability, fixation losses, and identification of the rod-free zone were used as reliability metrics. A subset underwent repeat testing within 4 weeks.ResultsThirty-nine participants (19 male and 20 female), median age 24 years (interquartile range, 9.5 years) and 23 years (interquartile range, 9 years) for the right and left eyes, respectively, completed testing. Overall 77 eyes underwent scotopic testing, with 82% meeting reliability criteria. Mean cyan and red sensitivities were 19.9 ± 1.1 dB and 20.9 ± 1.2 dB in right eyes, and 20.1 ± 1.4 dB and 21.3 ± 1.4 dB in left eyes, respectively. Volumetric cyan and red sensitivities were 2868 ± 157 dB.deg2 and 3077 ± 176 dB.deg2 in the right eyes, respectively, and 2892 ± 205 dB.deg2 and 3126 ± 207 dB.deg2 in the left eyes, respectively. Mean sensitivity coefficients of repeatability (CoR) were ± 1.4 dB (cyan) and ± 2.1 dB (red) while pointwise coefficients of repeatability were ± 7.2 dB (95% confidence interval, 6.5–7.6 dB) for cyan and ± 7.9 dB (95% confidence interval, 7.3–8.4 dB) for red, with no significant differences between eyes or genders. Fixation stability assessed using the 95% bivariate contour ellipse area for cyan was 2.9 ± 5.9 deg2 and 2.3 ± 2.2 deg2 for the right and left eyes, respectively, and for red were 0.7 ± 0.6 deg2 and 0.9 ± 0.8 deg2 for the right and left eyes, respectively. Again, there were no significant differences between cyan and red tests (Friedman test, bivariate contour ellipse area 63%, P = 0.455; bivariate contour ellipse area 95%, P = 0.432).ConclusionsScotopic microperimetry using the Scotopic Macular Integrity Assessment device was feasible and well-tolerated. Repeatability metrics demonstrated limitations in fine spatial mapping of scotopic retinal sensitivity.Translational RelevanceThis study highlights potential areas for future improvements in scotopic microperimetry before its use as an outcome measure in clinical trials for retinal disease.

Visual acuity is the most used method to assess visual function in children. Contrast sensitivity complements the information provided for visual acuity, but it is not commonly used in clinical practice. Digital devices are increasingly used as a method to evaluate visual function, due to multiple advantages. Testing with these devices can improve the evaluation of visual development in children from a few months of age. Visual acuity and contrast sensitivity tests, using eye tracking technology, are able to measure visual function in children across a wide range of ages, objectively, quickly and without need of an experienced examiner. To report age-normative values for grating visual acuity and contrast sensitivity in healthy children using a digital device with eye tracking technology and to validate the grating acuity test. In the first project of the study, we examined healthy children aged between 6months and 7years with normal ophthalmological assessment. Grating visual acuity (VA) and contrast sensitivity (CS) were assessed using a preferential gaze paradigm with a DIVE (Device for an Integral Visual Examination) assisted with eye tracking technology to provide age norms. For the validation project, we compared LEA grating test (LGT) with DIVE VA in a group of children aged between 6months and 4years with normal and abnormal visual development. Fifty-seven children (2.86 ± 1.55years) were examined with DIVE VA test and 44 successfully completed DIVE CS test (3.06 ± 1.41years). Both, VA and CS values increased with age, mainly along the first two years of life. Sixty-nine patients (1.34 ± 0.61years) were included in the DIVE VA test validation. The mean difference between LGT and DIVE VA was - 1.05 ± 4.54cpd with 95% limits of agreement (LoA) of - 9.95-7.84cpd. Agreement between the two tests was higher in children younger than 1year with a mean difference of - 0.19 ± 4.02cpd. DIVE is an automatic, objective and reliable tool to assess several visual function parameters in children, and it has good agreement with classical VA tests, especially for the first stage of life.

To investigate the influence of an eye ointment on functional visual acuity (FVA) and ocular wavefront aberration. In 11 healthy volunteers (6 men and 5 women), visual function parameters, such as FVA, visual maintenance ratios (VMR), and minimal visual acuity (minVA), were assessed by the FVA measurement system before and 2, 5, 10, 20, 30, 40, 50, 60, 90, 120, 180, and 240 min after administration of ofloxacin eye ointment. Ocular aberration was also measured, and the root mean square (RMS) of second-, third-, fourth-, and total higher-order aberrations was determined. The time course of changes in each parameter was statistically analyzed by using repeated-measures analysis of variance and the Dunnett post hoc test, and relationships between visual function and ocular aberration parameters were also analyzed by the Pearson correlation test. FVA, VMR, and minVA showed significant deteriorations at 2-, 5-, 10-, and 20 min after administration of eye ointment compared with the baseline values (P<0.05). All components of ocular wavefront aberration such as second-, third-, fourth-, and total higher-order RMS significantly increased at 2- and 5 min after the administration of eye ointment compared with the baseline values (P<0.05). In addition, deteriorations of these visual function parameters were significantly correlated with reduced blink numbers (Pearson's correlation coefficient; r=- 0.76, P=0.017 for FVA, r=0.79, P=0.013 for VMR, and r=-0.62, P=0.040 for minVA), and VMR was significantly related with changes in second-order RMS (r=-0.60, P=0.049). Eye ointment significantly reduced visual function for at least 20 min. Especially, minVA was worse than 0.155 logMAR, which is legally required for driving, for 3 h after the administration. In addition, increases in lower-order aberration and low blink rates were associated with the degradation of visual function.

Subjects with bilateral central vision loss (CVL) use a retinal region called the preferred retinal locus (PRL) for performing various visual tasks. We probed the fixation PRL in individuals with bilateral macular disease, including age-related macular degeneration (AMD) and Stargardt disease (STGD), for localized sensitivity deficits. Three letter words at the critical print size were presented in the NIDEK MP-1 microperimeter to determine the fixation PRL and its radial retinal eccentricity from the residual fovea in 29 subjects with bilateral CVL. Fixation stability was defined as the median bivariate contour ellipse area (BCEA) from 3 fixation assessments. A standard 10-2 grid (68 locations, 2° apart) was used to determine central retinal sensitivity for Goldmann size II test spots. Baseline and follow-up supra-threshold screening of the fixation PRL for localized sensitivity deficits was performed using high density (0.2° or 0.3° apart) 0dB Goldmann size II test spots. Custom MATLAB code and a dual bootstrapping algorithm were used to register test-spot locations from the baseline and follow-up tests. Locations where the 0dB test spots were not seen on either test were labeled as micro-scotomas (MSs). Median BCEA correlated poorly with the radial eccentricity of the fixation PRL. Mean (±SD) sensitivity around the PRL from 10-2 testing was 4.93±4.73dB. The average percentage of MSs was similar for patients with AMD (25.4%), STGD (20.3%), and other etiologies of CVL (27.1%). The fixation PRL in subjects with bilateral CVL frequently includes local regions of sensitivity loss.

Purpose: To evaluate fixation stability and retinal sensitivity in the central 10o in Intermediate Age-Related Macular Degeneration (AMD), correlating these values with focal retinal changes on retinography and fundus autofluorescence (FAF). Methods: A cross-sectional observational study enrolling patients with intermediate AMD, analyzed concerning microperimetric macular sensitivity (MP3 Microperimeter, Nidek®, Inc.), color retinography and FAF (Topcon® DRI OCT). Other variables considered were best corrected visual acuity (BCVA), fixation stability and FAF pattern. Results: This study evaluated 33 eyes of 18 patients with mean age of 75,55±6,14, and a mean BCVA of 71±9,1 letters (modified EDTRS grid). Mean retinal sensitivity was 21,9±5,04dB, and mean bivariate contour ellipse area (BCEA) 99,6% was 13,61±9,51o 2 , with 30,3% of eyes showing relatively unstable fixation. Concerning the individual analysis of macular points (N=561), we identified a greater decrease in retinal sensitivity in points of decreased FAF (17±8,3dB) and increased FAF (13,06±6dB) comparing with normal FAF (9,6±4,6dB) (p<0.001). Conclusions: Changes in FAF seem to be closely related to decreased focal retinal sensitivity. BCVA may be insufficient as a retinal function evaluation tool in intermediate AMD, with most patients showing altered fixation stability and multiple focal changes in retinal sensitivity in the central 10o. Microperimetry could become a valuable tool in functional follow-up of these patients, in correlation with FAF as a structural evaluation exam.

The aims of this study were 1) To evaluate retinal nerve fiber layer (fRNFL) thickness and ganglion cell layer plus inner plexiform layer (GCIPL) thickness at the fovea in eyes affected with traumatic optic neuropathy (TON) compared with contralateral normal eyes, 2) to further evaluate these thicknesses within 3 weeks following trauma (defined as “early TON”), and 3) to investigate the relationship between these retinal layer thicknesses and visual function in TON eyes. Twenty-nine patients with unilateral TON were included. Horizontal and vertical spectral-domain optical coherence tomography (SD-OCT) scans of the fovea were taken in patients with unilateral TON. The main outcome measure was thickness of the entire retina, fRNFL, and GCIPL in eight areas. Thickness of each retinal layer was compared between affected and unaffected eyes. The correlation between the thickness of each retinal layer and visual function parameters, including best corrected visual acuity, color vision, P100 latency, and P100 amplitude in visual evoked potential (VEP), mean deviation (MD) and visual field index (VFI) in Humphrey visual field analysis in TON eyes was analyzed. Thicknesses of the entire retina, fRNFL, and GCIPL in SD-OCT were significantly thinner (3–36%) in all measurement areas of TON eyes compared to those in healthy eyes (all p<0.05). Whereas, only GCIPL in the outer nasal, superior, and inferior areas was significantly thinner (5–10%) in the early TON eyes than that in the control eyes (all p<0.01). A significant correlation was detected between retinal layer thicknesses and visual function parameters including color vision, P100 latency and P100 amplitude in VEP, MD, and VFI (particularly P100 latency, MD, and VFI) (r = -0.70 to 0.84). Among the retinal layers analyzed in this study, GCIPL (particularly in the superior and inferior areas) was most correlated with these five visual function parameters (r = -0.70 to 0.71). Therefore, evaluation of morphological change of each retinal layer using SD-OCT can help in understanding TON pathophysiology and indirectly assessing visual function. Moreover, evaluation of the morphological change of the GCIPL in TON eyes may be useful to assess visual function in patients with early TON.

Purpose:Biofeedback training (BT) was adapted to idiopathic infantile nystagmus syndrome (IINS) cases to enhance visual functions and quality of life (QoL).Methods:10 patients (age 9 ± 3.2 years) treated with the audio-visual BT module of the MAIA microperimeter (Centervue, Padova, Italy) were assessed in two baseline visits and 1week post-BT (BT 80 min in total). The outcomes were distance and near binocular best corrected visual acuity (BBCVA), fixation stability, reading speed, contrast sensitivity, stereopsis and Children’s Visual Function Questionnaire. One-way repeated measured ANOVA and paired t-tests were used.Results:Distance BBCVA improved from 0.46 ± 0.21 and 0.43 ± 0.18 pre-BT to 0.33 ± 0.2 logMAR post-BT (F (2,27) = 13.75, p = 0.0002). Post-BT was better than baseline (p = 0.0001) and pre-BT (p = 0.001). Near BBCVA improved from 0.23 ± 0.09 and 0.21 ± 0.14 pre-BT to 0.04 ± 0.08 post-BT (F (2,27) = 22.12, p = 0.000014), post-BT was better than baseline (p = 0.0001) and pre-BT (p = 0.0006). Stereopsis improved from 283 ± 338″ to 39 ± 32.2″ (p = 0.04), contrast sensitivity from 0.26 ± 0.17 to 0.08 ± 0.12 log units (p = 0.01), and reading speed improved from 74.7 ± 51.2 wpm to 104.7 ± 53.6 wpm (p = 0.0006). Fixation stability improved from 33.6 ± 28.1 to 14.3 ± 10.1 sq. QoL increased from 23.8 ± 2.2 to 26.3 ± 2.3 units (p = 0.001).Conclusion:BT benefited all visual functions and QoL in this pilot study, heralding a new possibility for Low Vision Rehabilitation in IINS.

Non-vascularized pigment epithelial detachments (PED) are usually associated with dry age-related macular degeneration (AMD). In this study, we aimed to investigate the correlation between visual function and morphologic parameters. Seventeen eyes of eleven patients with non-vascularized AMD were enrolled. In addition to conventional optical coherence tomography (OCT), polarization-sensitive optical coherence tomography (PS-OCT) measurements were performed by evaluating the regularity of retinal pigment epithelium (RPE) entropy within the PED area. Retinal sensitivity was measured with MP-3 microperimetry, and retinal sensitivities within (RSin) and outside (RSout) the PED area were calculated. The relationship between OCT parameters and visual function was analyzed. As a result, there was a significant difference between the RSin and RSout (p < 0.001, Wilcoxon signed rank test). Moreover, RSin was significantly related to logMAR VA (p = 0.033, linear mixed model). The regularity of RPE entropy was significantly related to visual acuity and RSin (p = 0.00038, p = 0.031, linear mixed model), although neither the height nor area of PED correlated with visual function. Our results suggest that retinal sensitivity is significantly deteriorated within the PED area and RPE entropy measured with PS-OCT was closely related to visual function in eyes with non-vascularized PED.

The purpose was to investigate the effects of the spectral power distribution (SPD) and illuminance of task lighting on visual function in age-related macular degeneration (ARMD) compared to normal healthy eyes. Twenty-eight subjects with ARMD and 18 age-matched normal subjects were studied. The effects on visual function were determined for four common task light sources: standard pearl coat incandescent (SP), daylight blue incandescent (DL), warm white fluorescent (WW) and cool white fluorescent (CW). Apart from a small, statistically significant improvement in contrast sensitivity with DL compared to SP lighting (0.5 dB, p = 0.01), there were no significant effects of SPD on other visual functions and no differences in the effects for subjects with ARMD and those with normal vision. Thus, for task lighting typically used in low vision rehabilitation, the SPD would seem to be of minimal clinical importance to visual function. However, increasing the task illuminance had a greater effect on visual function, in particular for subjects with ARMD (p < 0.01). For an increase in illuminance from 300 to 3000 lux, the mean increase in contrast sensitivity and near visual acuity was 1.5 dB and 0.13 log MAR, respectively. Although this effect is not large, we suggest that it is clinically relevant and supports the provision of additional task illuminance as an important part of low vision rehabilitation for patients with ARMD.

Purpose. To assess visual function and its response to serial intravitreal ranibizumab (Lucentis, Genentech) in patients with neovascular age-related macular degeneration (nv-AMD). Methods. Forty-seven eyes of 47 patients with nv-AMD, and corrected distance visual acuity (CDVA) logMAR 0.7 or better, undergoing intravitreal injections of ranibizumab, were enrolled into this prospective study. Visual function was assessed using a range of psychophysical tests, while mean foveal thickness (MFT) was determined by optical coherence tomography (OCT). Results. Group mean (±sd) MFT reduced significantly from baseline (233 (±59)) to exit (205 (±40)) (P = 0.001). CDVA exhibited no change between baseline and exit visits (P = 0.48 and P = 0.31, resp.). Measures of visual function that did exhibit statistically significant improvements (P < 0.05 for all) included reading acuity, reading speed, mesopic and photopic contrast sensitivity (CS), mesopic and photopic glare disability (GD), and retinotopic ocular sensitivity (ROS) at all eccentricities. Conclusion. Eyes with nv-AMD undergoing intravitreal ranibizumab injections exhibit improvements in many parameters of visual function. Outcome measures other than CDVA, such as CS, GD, and ROS, should not only be considered in the design of studies investigating nv-AMD, but also in treatment and retreatment strategies for patients with the condition.

To report the change of contrast sensitivity (CS) after photodynamic therapy (PDT) vs full macular translocation (FMT) for neovascular age-related macular degeneration (AMD), and to relate this to other measures of visual function (distance and near acuity). Fifty patients (50 eyes) with predominantly classic subfoveal choroidal neovascularisation (CNV) secondary to AMD were randomized to PDT or FMT. CS was measured with Pelli-Robson charts. Acuity scores of near visual function (NVS) were calculated after testing with visual acuity cards of the Swiss National Association of and for the Blind (SNAB). Best corrected distance visual acuity (DVA) was determined according to a standardized protocol with EDTRS charts. Primary end point was the change of CS at 12-month examination from baseline. The interaction of the CS with NVS and DVA was analysed. Mean CS showed a decrease in both treatment groups (FMT: -2 letters, PDT: -3 letters, p=0.969) at 12-month examination from baseline. While mean NVS improved by seven letters in the FMT group, a decrease of more than ten letters was seen in the PDT group (p<0.05). We found no agreement between CS and high-contrast acuity (NVS, DVA). In FMT patients, the parameters at baseline (CS, NVS, DVA) correlated poorly with the corresponding 12-month results, therefore providing no informative basis to predict the later functional development. In contrast, PDT patients showed strong baseline-to-outcome coherence with baseline measures also associated with better final values. Although FMT can initiate recovery of near and distance acuity over the period of 1 year in selected patients with classic CNV, CS did not differ between FMT and PDT. We found no close connection of CS with DVA or NVS, especially after FMT. Knowledge about the unequal variation of visual parameters can provide more comprehensive information when advising patients on different therapeutic options. That also applies in particular to vascular endothelial growth factor inhibitors, which seem to promise an even higher extent of gain in CS and to reach the peak of recovery at an earlier time.