Macular Integrity Assessment Microperimeter Research Articles

Innovative vision rehabilitation method for hemianopsia: Comparing pre- and post audio-luminous biofeedback training for ocular motility improving visual functions and quality of life.

Homonymous hemianopsia (HH) corresponds to vision loss in one hemi-field secondary to retro-chiasmal injury. Patients with HH experience difficulties in scanning and orientation in their environment. Near vision daily activities such as reading can also be impaired. There is an unmet need for standardized vision rehabilitation protocols for HH. We investigated the effectiveness of biofeedback training (BT), used for vision rehabilitation in patients with central vision loss, in individuals with HH. In this prospective pilot pre/post study, 12 participants, with HH consecutive to brain injury, performed 5 weekly BT sessions for 20 min each under supervision using the Macular Integrity Assessment microperimeter. BT consisted of relocation of the retinal locus 1-4° toward the blind hemi-field. Outcomes measured post-BT were paracentral retinal sensitivity, visual acuity (near vision), fixation stability, contrast sensitivity, reading speed, and visual functioning questionnaire. Statistical analysis was performed using Bayesian paired t-tests. Paracentral retinal sensitivity significantly increased by 2.7 ± 0.9 dB in the treated eye in 9/11 of the participants. Significant improvements with medium-to-large effect size were observed for fixation stability (8/12 participants), contrast sensitivity (6/12 participants) and near vision visual acuity (10/12 participants). Reading speed increased by 32.5 ± 32.4 words per minute in 10/11 participants. Quality of vision scores improved significantly with large effect size for visual ability, visual information and mobility. BT led to encouraging improvements in visual functions and functional vision in individuals with HH. Further confirmation with larger trials is required.

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

ABSTRACT 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.

MAIA microperimeter for short-duration fixation stability measurements in central vision loss: Repeatability and comparison with the Nidek MP1.

This study reports the repeatability of 20s-duration fixation stability measurements recorded with the Macular Integrity Assessment (MAIA) microperimeter in patients with central vision loss, in contrast to the Nidek MP1microperimeter. Fixation stability was recorded in 39 eyes of 25 patients with macular disease using MAIA and the MP1 for 20s intervals, twice for each eye, with each instrument. Twenty eyes were identified as the better eye (BE) and 19 eyes as the worse eye (WE). Fixation stability was quantified with the 95% bivariate contour ellipse area (BCEA), logarithmically transformed. Bland-Altman plots were used to determine the 95% limits of agreement. For MAIA, the 95% limits of agreement were ±0.84log deg2 for the BE and ±0.66log deg2 for the WE. Similarly, for the MP1 these limits were ±0.48log deg2 for the BE and ±0.72log deg2 for the WE. Inter-device repeatability was modest, ±1.09log deg2 for the BE and ±1.01log deg2 for the WE, and a proportional bias was detected. Occasionally, MAIA did not register all the expected number of data points, and included far outliers in the BCEA calculation; the inter-device repeatability did not improve when these outliers were removed. Repeatability of 20s-duration fixation stability examination in patients with central vision loss is specific to the instrument used. We recommend that only data from same type of microperimeter with the same fixation duration should be compared when using fixation stability as an outcome measure to monitor disease progression, effect of treatment or in clinical trials.

Macular integrity assessment microperimeter, Humphrey field analyzer and OCT in glaucoma practice: a correlation study

ObjectiveTo compare and correlate retinal sensitivities measured with macular integrity assessment microperimetry (MAIA-MP) and Humphrey field analyzer (HFA) 10-2 tests with structural parameters obtained from optical coherence tomography (OCT) in primary open-angle glaucoma (POAG) and ocular hypertension. MethodsThis study included 63 participants (22 with POAG, 20 with ocular hypertension, and 21 control individuals). All participants underwent HFA 10-2 and MAIA-MP (macular retinal sensitivity tests) and measurements for optic nerve head (ONH), peripapillary retinal nerve fibre layer thickness (PRNFLT), and ganglion cell inner plexiform layer thickness (GCIPLT) using OCT. The relationship between macular retinal sensitivity and OCT parameters was evaluated by Pearson correlation analysis and linear regression modelling. ResultsPOAG cases had a strong association between the MAIA-MP and ONH parameters (optic disc area [ODA], p = 0.037; cup volume, p = 0.043), PRNFLT (average, p = 0.009; inferior PRNFLT, p = 0.004), and GCIPLT in all macula sectors (p ≤ 0.005 for all). HFA 10-2 had a moderate correlation with the ONH parameters (cup-to-disc ratio [CDR], p = 0.042; vertical CDR, p = 0.037; cup volume, p = 0.037; ODA, p = 0.014), PRNFLT (average, inferior, and nasal, p < 0.05 for all), and GCIPLT in all macula sectors (p < 0.005 for all). OHT cases had a weak correlation between HFA 10-2 and nasal and superior PRNFLTs (p = 0.035 and p = 0.047, respectively). ConclusionMAIA-MP and HFA 10-2 functional parameters have strong correlations with the structural parameters obtained by OCT in POAG cases. Both devices are useful in assessing the central visual field in glaucoma, with MAIA-MP potentially beneficial in patients with limited cooperation or poor vision.

Improved sensitivity of microperimetric outcomes for clinical studies in age-related macular degeneration

To investigate sensitive outcome measures based exclusively on abnormal points in microperimetry testing of eyes with intermediate age-related macular degeneration (iAMD). 25 eyes of 25 subjects with iAMD had undergone 2 successive tests of mesopic microperimetry with the Macular Integrity Assessment Microperimeter (MAIA), using a custom grid of 33 points spanning the central 14 degrees of the macula. Each point was defined as abnormal if its threshold sensitivity was lower than 1.65 standard deviations (SD) (5%) or 2 SD (2.5%) than the expected threshold in healthy eyes according to the MAIA internal database. Among the 25 eyes there were 11.8 ± 9 and 8.4 ± 8.2 abnormal points at < 5% and < 2.5%, with mean deviation of thresholds from normal − 4.9 ± 1.2 dB and − 5.8 ± 1.5 dB, respectively. These deviations were greater, and their SD smaller, compared with the complete microperimetry grid, − 2.3 ± 2.0 dB. The 95% limits of agreement for average threshold between the 2 successive tests were smaller when only abnormal points were included. Analyzing only abnormal grid points yields an outcome parameter with a greater deviation from normal, a more homogenous dataset, and better test–retest variability, compared with analysis of all grid points. This parameter may thus be more sensitive to change, while moderately limiting the number of potential recruits. The proposed outcome measures should be further investigated as potential endpoints in clinical trials in iAMD.

Determinants of Test Variability in Scotopic Microperimetry: Effects of Dark Adaptation and Test Indices.

PurposeTo test the effect of different dark adaptation conditions and reliability indices on the variability of two color scotopic microperimetry.MethodsWe analyzed data from 22 consecutive visually healthy adults. Scotopic microperimetry was performed (Macular Integrity Assessment microperimeter, CenterVue, Padua, Italy) with two wavelength stimuli, cyan (505 nm) and red (627 nm), after a dark adaptation time of 10, 20, or 30 minutes. All tests were repeated twice to measure test–retest variability with Bland–Altman plots. We also provide a method to more accurately quantify the false-positive (FP) responses based on response data (button pressing) from the device, similar to FP responses used in standard static perimetry. Data on fixation stability (95% bivariate contour ellipse area) and blind spot responses were also extracted. Their relationship with measured sensitivity (in decibels) and test–retest variability was quantified through linear mixed effect models.ResultsDark adaptation had a significant effect on the sensitivity (dB) measured with the cyan stimulus (P < 0.001), but no effect on the red stimulus. Of the three metrics, the novel FP responses showed the best association with test–retest variability and was the only predictor consistently significant for all tests (P < 0.01).ConclusionsDark adaptation protocols should be carefully standardized for scotopic testing, especially if a cyan stimulus is used. The proposed FP responses should be used to assess reliability of microperimetry examinations instead of other metrics.Translational RelevanceWe developed a method to calculate a more accurate estimate of the FP responses using data available to all researchers, generalizable to all Macular Integrity Assessment microperimeter tests.

Microperimetry in Age-Related Macular Degeneration: An Evidence-Base for Pattern Deviation Probability Analysis in Microperimetry.

PurposeThe “traffic light” color designation of differential light sensitivity used in a number of microperimeters does not encompass the conventional Total and Pattern Deviation probability analyses adopted by standard automated perimetry. We determined whether the color designation is indicative of abnormality as represented by the “gold standard” Pattern Deviation probability analysis.MethodsTotal and Pattern Deviation probability levels, using two different methods, were derived at each of 40 stimulus locations, within 7° eccentricity, from 66 ocular healthy individuals (66 eyes) who had undergone microperimetry with the Macular Integrity Assessment microperimeter. The probability levels were applied to the corresponding fields from each of 45 individuals (45 eyes) with age-related macular degeneration (AMD) and evaluated in relation to the color designation.ResultsSensitivities designated in orange encompassed the entire range of Pattern Deviation probability levels (from normal to P ≤ 1%). Those designated in green were mostly normal; those in red/black generally corresponded to the ≤1% probability level.ConclusionsThe green and the red/black designations are generally indicative of normal and abnormal probability values, respectively. The orange designation encompassed all probability outcomes and should not be relied upon for visual field interpretation. The evidence base indicates replacement of the color designation of sensitivity in AMD by Total Deviation and Pattern Deviation analyses.Translational RelevanceThe use of Total and Pattern Deviation probability analyses is not universal in all microperimeters, and the derivation of these values indicates that color coding will lead to errors in evaluating visual field loss.

Associations between Macular Sensitivity and Fixation in Pseudophakic Children after Congenital Cataract Surgery

ABSTRACTPurpose: To investigate the associations between macular sensitivity (MS) and fixation in pseudophakic children after congenital cataract surgery.Materials and Methods: In total 55 pseudophakic eyes and 28 healthy phakic eyes were included in this cross-sectional study. MS and fixation stability in term of 95% bivariate contour ellipse area (BCEA) were assessed with a Macular Integrity Assessment microperimeter. Central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) was measured with optical coherence tomography. MS inside and outside the 95% BCEA was compared. Influencing factors for the difference in MS between the two regions (ΔMS) were assessed.Results: The overall MS was significantly lower in pseudophakic eyes than in the controls (P < .001). In the pseudophakic group, fixation stability was stable/relatively unstable/unstable in 69.1%/16.4%/14.5% of eyes, and their MS was 27.60 ± 2.56, 25.02 ± 3.82, and 20.50 ± 7.15 dB, respectively. The unstable subgroup had significantly worse MS than the stable subgroup (P < .001). Among pseudophakic eyes, the MS inside the 95% BCEA (fixation preferred region) was significantly greater than that outside this region (P = .048), and it was more correlated with BCVA than that of the entire macula. The ΔMS became greater in those pseudophakic eyes with worse fixation stability (P < .001) and longer axial length (P = .002). Backward stepwise multiple linear regression also revealed 95%BCEA and axial length had significant influences on ΔMS (R2 = 0.289, P < .001).Conclusion: MS was lower in pseudophakic eyes with poor fixation. Macular sensitivity inside and outside the fixation preferred region was different in pseudophakic children after congenital cataract surgery, and this difference increased with longer axial length and poorer fixation.

MICROPERIMETRY IN BEST VITELLIFORM MACULAR DYSTROPHY.

To investigate retinal sensitivity in eyes with all the clinical stages of Best vitelliform macular dystrophy (VMD). Thirty-two patients affected by VMD in subclinical, vitelliform, pseudohypopyon, vitelliruptive, and atrophic stages were enrolled in this prospective cross-sectional study. Patients underwent a complete ophthalmologic examination, including determination of best-corrected visual acuity (BCVA), staging of the disease (Gass's classification), and microperimetry by means of the macular integrity assessment microperimeter. The primary outcome measure was to describe the alterations in the retinal sensitivity of eyes affected by VMD in different stages. Secondary outcome measures included correlations between retinal sensitivity and best-corrected visual acuity and the correlation between the VMD stage and the specific microperimetry pattern. Mean retinal sensitivity was reduced in all the VMD stages. Nevertheless, vitelliform, pseudohypopyon, and vitelliruptive stages turned out to be very similar, especially within 10°. Fixation was classified as stable in 27 eyes (44.2%), relatively unstable in 16 eyes (26.2%), and unstable in 18 eyes (29.5%). Fixation stability correlated both with the disease stage and best-corrected visual acuity. VMD is characterized by complex microperimetric abnormalities, involving the whole macular area. Microperimetry may contribute to the global clinical assessment of patients affected by VMD and could be used in future therapeutic approaches.

Effects of pupil dilation on MAIA microperimetry.

Macular Integrity Assessment microperimetry assesses macular sensitivity to projected point light sources and maps eye movements to assess fixation stability. Although microperimetry is gaining prominence as an assessment tool in clinical and research settings, there is no consensus on whether it should be performed before or after pupil dilation. No studies to date have examined the effect of pupil dilation on results. The aim of this project was to elucidate the effect of pupil dilation on microperimetry outcomes. Prospective audit. Twenty healthy patients from postoperative cataract clinic and 10 patients with choroideremia to simulate a disease with peripheral visual field loss. Subjects underwent 10-2 68-point field testing using the Macular Integrity Assessment microperimeter on each eye. Subjects then underwent randomized dilation of one eye, and the test was repeated in both eyes. We compared changes in threshold sensitivity and fixation stability pre-pupil and post-pupil dilation. The undilated eye was analysed for any learning or fatigue effect caused by test repetition. Dilation produced no significant effect on threshold sensitivity (dilation effect: -0.29 decibels, P=0.23) or fixation stability in healthy controls or in choroideremia patients (dilation effect: +0.08log bivariate contour ellipse area, P=0.14). There was also no significant learning effect seen in the undilated eye, with no improvement in threshold sensitivity (order of eye testing: +0.03log bivariate contour ellipse area, P=0.71). In the clinical setting, patients may be tested for 10 degree microperimetry with or without pupil dilation, as both scenarios yield consistent and interchangeable results.

Reference Clinical Database for Fixation Stability Metrics in Normal Subjects Measured with the MAIA Microperimeter.

PurposeThe purpose of this study was to establish a normal reference database for fixation stability measured with the bivariate contour ellipse area (BCEA) in the Macular Integrity Assessment (MAIA) microperimeter.MethodsSubjects were 358 healthy volunteers who had the MAIA examination. Fixation stability was assessed using two BCEA fixation indices (63% and 95% proportional values) and the percentage of fixation points within 1° and 2° from the fovea (P1 and P2). Statistical analysis was performed with linear regression and Pearson's product moment correlation coefficient.ResultsAverage areas of 0.80 deg2 (min = 0.03, max = 3.90, SD = 0.68) for the index BCEA@63% and 2.40 deg2 (min = 0.20, max = 11.70, SD = 2.04) for the index BCEA@95% were found. The average values of P1 and P2 were 95% (min = 76, max = 100, SD = 5.31) and 99% (min = 91, max = 100, SD = 1.42), respectively. The Pearson's product moment test showed an almost perfect correlation index, r = 0.999, between BCEA@63% and BCEA@95%. Index P1 showed a very strong correlation with BCEA@63%, r = −0.924, as well as with BCEA@95%, r = −0.925. Index P2 demonstrated a slightly lower correlation with both BCEA@63% and BCEA@95%, r = −0.874 and −0.875, respectively.ConclusionsThe single parameter of the BCEA@95% may be taken as accurately reporting fixation stability and serves as a reference database of normal subjects with a cutoff area of 2.40 ± 2.04 deg2 in MAIA microperimeter.Translational RelevanceFixation stability can be measured with different indices. This study originates reference fixation values for the MAIA using a single fixation index.

Fixation Stability and Refractive Error After Cataract Surgery in Highly Myopic Eyes

To analyze the refractive error in highly myopic eyes after cataract surgery and investigate the possible impact of fixation stability on it. Secondary data analysis from a previous prospective study. Clinical data of 98 eyes of 98 consecutive patients with high myopia and 42 eyes of 42 controls, which underwent cataract surgery, were analyzed. Refractive error was calculated 1month after surgery based on both Sanders-Retzlaff-Kraff theoretic (SRK/T) and Holladay 1 formulas. Fixation stability was evaluated using the Macular Integrity Assessment microperimeter system, which assessed the fixation pattern in terms of 63% and 95% of the bivariate contour ellipse area (BCEA). Multiple linear regression analysis was performed to identify independent predictors of postoperative refractive error. The highly myopic cataract group had greater hyperopic refractive errors (P < .001 for both formulas) and larger 63% and 95% BCEA values (P= .033 and P= .034) than the control group. In the highly myopic group, the factors 63% or 95% BCEA were positively correlated with the postoperative refractive error (SRK/T formula, r= 0.383, P < .001 and r= 0.320, P= .002, respectively). Multiple linear regression analysis showed that with the SRK/T formula, postoperative refractive error in highly myopic eyes was significantly correlated with axial length (β= 0.491, P < .001), 63% BCEA (β= 0.181, P= .045), and corneal curvature (β=-0.190, P= .024). The refractive error was no longer associated with corneal curvature after using the Holladay 1 formula. Highly myopic eyes usually had hyperopic refractive errors after cataract surgery. Fixation stability might serve as an important determinant of postoperative refractive errors in this population.

Test-Retest Repeatability of Microperimetry at the Border of Deep Scotomas.

The purpose of this study was to examine the test-retest repeatability of microperimetric sensitivity at the border of deep scotomas. Thirty normal participants underwent two examinations, each on the Macular Integrity Assessment (MAIA) microperimeter and on the MP-1 microperimeter (four examinations in total). A customized stimulus pattern allowed microperimetric sensitivity to be measured at the border of the optic nerve head (ONH), which acted as a model for the border of a deep scotoma-and also at the macular and peripapillary region. There were no significant changes in average point-wise sensitivity (PWS) values between the two examinations for all three regions using the MAIA microperimeter (P ≥ 0.262). The PWS coefficient of repeatability (CoR) was ±12.99 dB at the border of the ONH, which was significantly larger than points in the macular and peripapillary regions (P > 0.001). A significant decrease in average PWS, using the MP-1 microperimeter at the macular and peripapillary region (P < 0.001), meant that the PWS CoR could not be determined in these regions. No significant changes in average PWS were observed at the border of the ONH (P = 0.223), and the PWS CoR was ±7.52 dB in this region. Microperimetric test-retest repeatability at the border of a deep scotoma was worse than at other areas of normal retina, and this highlights the limitation of applying a single estimate of test-retest repeatability to determine whether significant functional decline has occurred at the border of a deep scotoma.

A Simplified Method of Identifying the Trained Retinal Locus for Training in Eccentric Viewing

In the typical human visual system, the macula allows for high visual resolution. Damage to this area from diseases, such as age-related macular degeneration (AMD), causes the loss of central vision in the form of a central scotoma (Kanski, 2008). Since no treatment is available to reverse AMD, providing low vision rehabilitation to compensate for the loss of central vision is invaluable for individuals with this condition. Teaching persons with a central scotoma the technique of eccentric viewing to use their remaining peripheral retina to read and perform tasks of daily living has been shown to be effective (Nilsson, Frennesson, & Nilsson, 2003; Petre, Hazel, Fine, & Rubin, 2000; Vukicevic & Fitzmaurice, 2002). It has been reported that persons with AMD can unconsciously adopt an eccentric area of the uncompromised retina, allowing them to achieve better vision. This eccentric area acts as a pseudo-fovea and is termed the preferred retinal locus (PRL) (Schuchard, 1995; Timberlake et al., 1986). Although useful, this spontaneous choice of location may not provide optimal vision for individuals to perform various visual tasks, such as reading, recognizing faces, or performing activities of daily living. Optimizing the location of the retinal area used can be addressed with formal training in eccentric viewing to teach individuals to use a more suitable part of their retina to see by introducing a trained retinal locus (TRL) (Culham, Silver, & Bird, 1990; Fletcher, Schuchard, & Watson, 1999; Nilsson et al., 2003; Vukicevic & Fitzmaurice, 2005, 2009). Although there are many methods for training eccentric viewing, the fundamental principles are equivocal and involve two stages: 1. Identification of the residual areas of the healthy retina by mapping the individual's visual field and 2. Location of the most suitable area to be used as the TRL on the basis of the proximity to the fovea. A number of methods and apparatuses are available to chart the visual field, but the preferred method is by microperimetry with such devices as the Macular Integrity Assessment Microperimeter (CenterVue SpA, Padova, Italy) or the Nidek MP-1 Micro Perimeter (Nidek Technologies Srl, Padova, Italy). Alternately, the visual field can be mapped by tangent screen perimetry, such as the Bjerrum tangent screen. Microperimetry allows clinicians to precisely delineate the borders of the scotoma and the corresponding visible pathology on the retina. The technique is also capable of displaying direct, real-time observation of the retina, and stimuli can be placed on the retina for the purposes of training in eccentric viewing. For this reason, microperimetry is useful (Sunness, Bressler, & Maguire, 1995; Timberlake et al., 1986). Nevertheless, microperimetry is not widely used clinically because it is considered to be the least popular method of identifying the retinal locus for eccentric viewing training (Weisser-Pike, 2008). Low vision practitioners have reported that microperimeters are difficult to use and difficult for clients to understand how to perform the required task. The preference is for simpler methods, such as the Amsler grid or the Bjerrum tangent screen. Clinicians' preference is not the only issue that restricts the clinical use of microperimetry in a low vision setting: it is expensive equipment and hence is generally reserved for research purposes (Manivannan et al., 2001). Low vision practitioners commonly use the Bjerrum tangent screen as a method of mapping the central visual field or the central scotoma or both. The Bjerrum tangent screen is a black felt screen that evaluates the central 30 degrees of the retina at a one- or two-meter (about 3 feet or 6.5 feet) testing distance. The Bjerrum has statico-kinetic properties that allow the borders of the scotoma to be accurately charted (kinetically) and individual test points to be grossly quantified (statically). …