Bivariate Contour Ellipse Area Research Articles

Stargardt Macular Dystrophy: Changes in Fixation When Asked to Look Straight Ahead

To examine whether individuals with Stargardt disease macular dystrophy (STGD) change the location of fixation with instruction. Case-control study. Thirteen normally sighted and 37 STGD participants. Using an Optos scanning laser ophthalmoscopy/OCT microperimeter (Optos plc, Dunfermline, UK), fixation was measured under 2 different instructions: "look at the cross" (LC) and "look straight ahead, even if you do not see the cross" (LS). Visual acuity, contrast sensitivity, disease duration, and age at disease onset were obtained from medical records. Change in fixation with instruction. Mean age of the STGD participants was 39.2 years, and 24 were women. Mean acuity was 1.01±0.29 logarithm of the minimum angle of resolution (logMAR), and mean contrast sensitivity was 1.16±0.41 log. The largest number of fixations under the LC condition were in the superior retina. Patients with STGD were divided into 3 groups, depending on the change in fixation locus when asked to look straight ahead: those having fixation closer the fovea, those with no change in the location of fixation, and those looking farther away from the fovea. Fifty-one eyes of 32 participants had fixations closer to the fovea when asked to look straight ahead (average change, -6.3°), whereas 13 eyes of 11 participants did not change fixation. There were no significant differences between groups in age, visual acuity, contrast sensitivity, bivariate contour ellipse area, and age at disease onset. Despite having eccentric fixation, most STGD participants did not have a complete directional re-referencing from the fovea to the eccentric location, and moved fixation when asked to look straight ahead. This finding emphasizes that reliable assessment of visual function during evaluations of disease progression or in therapeutic intervention trials requires consistent instructions and monitoring of fixation. Otherwise, a patient's interpretation of fixation instruction may confound the results.

Correlation between retinal function and microstructural foveal changes in intermediate age related macular degeneration

Purpose To assess foveal microstructural changes influencing retinal sensitivity (RS) and fixation stability using microperimeter MP-1 in intermediate age-related macular degeneration (AMD).Methods In this cross-sectional study, 22 eyes of 22 patients (mean age: 75 ± 9.02 years) with intermediate AMD were enrolled. Retinal sensitivity and bivariate contour ellipse area (BCEA) were obtained by microperimetry MP-1 (Humphrey 10-2 68-loci grid) under mesopic conditions. Drusen type, drusenoid pigment epithelial detachment, hyperreflective foci (HF), integrity of external limiting membrane (ELM), inner ellipsoid zone (ISel), RPE/Bruch’s membrane complex (RPE/B) and subfoveal choroidal thickness were analyzed in the foveal region and compared with RS and BCEA. Spearman’s rank correlation coefficient was used to evaluate the relationship between variables. Logistic regression analysis was also used to assess morphological predictor influencing RS or BCEA.ResultsRS was strongly and inversely related with the presence of HF (r = −0.66, P = 0.001), integrity of ELM (r = −0.70, P < 0.001), ellipsoid zone (r = −0.45, P = 0.03). Instead, BCEA is positively related to the ellipsoid zone integrity (r = 0.45, P = 0.03). Logistic regression analysis confirmed that disruption of ISel influenced fixation stability (ExpB: 9.69, P = 0.04) but not RS. Instead, the presence of HF and disruption of ELM predicted RS reduction (ExpB: 0.55, P = 0.02 and ExpB: 0.29, P = 0.04, respectively).ConclusionsThe integrity of ELM and the presence of HF are both predictors of RS. The ELM status may be considered a new biomarker of retinal function together with HF. Instead, the integrity of ISel band seems to be a more selective predictor of BCEA than RS.

Fixation Stability Recording: How Long for Eyes with Central Vision Loss?

Fixation examination with the MP-1 microperimeter (Nidek Technologies Srl., Vigonza, PD, Italy) determines the preferred retinal loci and fixation stability in patients with central vision loss. It is typically done for periods of 15 to 30 s as per the manual's recommendations, which are arbitrary. In this study, we examined (1) whether fixation stability depends on the duration of recording and (2) whether fixation stability changes over time. Raw eye-position data from 76 patients with bilateral central vision loss (mean age = 80 ± 9.6 yrs) who had fixation examination recordings with the MP-1of at least 15 s were used. Bivariate contour ellipse areas (BCEAs) were calculated and compared for intervals of 0 to 5 s, 0 to 10 s, and 0 to 15 s and for three consecutive 5-s intervals (0-5 s, 5-10 s, and 10-15 s). Ellipse's centroid location, axes extent, and tilt angle were also evaluated for each of these intervals. BCEA worsened significantly with increasing the time of fixation recording (P < .001). Compared to the BCEA during the first 5 s of examination recording, median BCEA increased by a factor of 1.4 for the first 10 s and of 1.6 for the first 15 s of recording. However, the bivariate ellipses for the three consecutive 5-s intervals were the same in terms of area, centroid location, and axes extent, but differed significantly in tilt angle (P = .005). Fixation stability (BCEAs) results were also confirmed with an additional analysis performed on shorter sampling intervals. Fixation stability deteriorates with increasing duration of the fixation recording, but when fixation is evaluated in shorter consecutive 5-s intervals, only a difference in ellipse's tilt angle is found. These results suggest that the current recommendations for fixation stability recording with the MP-1 can be shortened to a less demanding duration.

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.

Normal values for microperimetry with the MAIA microperimeter: sensitivity and fixation analysis in healthy adults and children.

To establish normative values of retinal sensitivity and parameters describing the fixation pattern using macular analyzer integrity assessment (MAIA) microperimetry (Centervue, Padova, Italy) in adults and children. A sample of 237 eyes of 237 healthy subjects aged between 10 and 70 years (mean age 30.63 ± 16.23 years) was evaluated using the MAIA microperimeter. The following parameters provided by the MAIA device were evaluated: average threshold (AT), macular integrity, fixation indexes (P1% and P2%), bivariate contour ellipse area (BCEA) for 95% and 63% of points, and horizontal (H) and vertical (V) axes of the ellipse of fixation. Differences between different age-related groups were evaluated. Correlation of microperimetric parameters with age was also assessed. Median retinal sensitivity of the overall sample was 32.90 dB (interquartile range 1.80 dB). Median P1 and P2 values were 98.00% (6.00) and 100.00% (1.00), respectively. Median BCEA for 95% and 63% of points were 2.40°2 (4.50) and 0.30°2 (0.50), respectively. Median H and V were 0.90° (0.80) and 0.90° (0.70), respectively. Age was significantly correlated with the following parameters in subjects from 21 to 70 years of age (p<0.01): AT (rho -0.47), P1 (rho -0.37), BCEA95 (rho 0.43), BCEA63 (rho 0.42), H (rho 0.43), and V (rho 0.40). Retinal sensitivity in healthy eyes tends to decrease with age as well as the stability of the pattern of fixation. A normative database in terms of retinal sensitivity threshold and fixation performance can be established in this type of eyes.

Microperimetric evaluation in patients with adult-onset foveomacular vitelliform dystrophy.

Introduction:To compare mean best-corrected visual acuity (BCVA), retinal sensitivity (RS), and bivariate contour ellipse area (BCEA) in patients with adult-onset foveomacular vitelliform dystrophy (AOFVD) and healthy subjects (HSs), reporting also functional disease-related changes in the different stages of the AOFVD disease.Materials and Methods:In this observational cross-sectional study, a total of 19 patients (30 eyes; 12 female and 7 male) with AOFVD were enrolled, and 30 patients (30 eyes; 16 female and 14 male) were recruited as age-matched control group (74.36 ± 9.17 years vs. 71.83 ± 6.99 years respectively, P = 0.11). All patients underwent a complete ophthalmologic examination, fundus autofluorescence and fluorescein angiography, spectral-domain optical coherence tomography and microperimetry (MP)-1 analysis. The data collection included mean BCVA, mean RS measured by means of MP-1, BCEA, and central retinal thickness.Results:All the functional parameters (BCVA, RS, and BCEA) were significantly worse in AOFVD group than HS. Subgroup analysis showed that the most significant functional changes, quantified by mean BCVA, RS, and BCEA, were in the atrophic stage (P = 0.03, P = 0.01, and P = 0.001, respectively). All the functional parameters were well correlated in the different stages.Conclusions:This study further confirms the good visual prognosis in the AOFVD eyes. Fixation stability measurement using BCEA demonstrates good evaluation of visual performance integrating traditional functional parameters. It may also serve for further rehabilitative purposes in atrophic eyes.

Feasibility of Macular Integrity Assessment (MAIA) Microperimetry in Children: Sensitivity, Reliability, and Fixation Stability in Healthy Observers.

To assess the feasibility of macular integrity assessment (MAIA) microperimetry (MP) in children. Also to establish representative outcome measures (differential light sensitivity, fixation stability, test-retest reliability) for children without visual impairment. Thirty-three adults and 33 children (9-12 years) were asked to perform three monocular MAIA examinations within a single session (dominant eye only). Children exhibited poorer test-retest reliability than adults for measures of both mean sensitivity (95% coefficient of repeatability [CoR95] = 2.7 vs. 2.3 dB, P = 0.036) and pointwise sensitivity (CoR95 = 6.2 vs. 5.7 dB, P < 0.001). Mean sensitivity was lower in children (27.6 vs. 29.5 dB, P < 0.001), and fixation stability was poorer (95% bivariate contour ellipse area [BCEA95] = 4.58 vs. 1.14, P < 0.001). Mean sensitivity was negatively correlated with fixation stability (r = -0.44, P < 0.001). Both children and adults exhibited substantial practice effects, with mean sensitivity improving by 0.5 dB (adults) and 0.9 dB (children) between examinations 1 and 2 (P ≤ 0.017). There were no significant differences between examinations 2 and 3 (P ≥ 0.374). Microperimetry is feasible in 9- to 12-year-old children. However, systematically lower sensitivities mean that the classification boundary for "healthy" performance should be lowered in children, pending development of techniques to improve attentiveness/fixation that may reduce or remove this difference. High measurement variability suggests that the results of multiple tests should be averaged when possible. Learning effects are a potential confound, and it is recommended that the results of the first examination be discarded.

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.

Smaller Fixation Target Size Is Associated with More Stable Fixation and Less Variance in Threshold Sensitivity.

The aims of this randomized observational case control study were to quantify fixation behavior during standard automated perimetry (SAP) with different fixation targets and to evaluate the relationship between fixation behavior and threshold variability at each test point in healthy young participants experienced with perimetry. SAP was performed on the right eyes of 29 participants using the Octopus 900 perimeter, program 32, dynamic strategy. The fixation targets of Point, Cross, and Ring were used for SAP. Fixation behavior was recorded using a wearable eye-tracking glass. All participants underwent SAP twice with each fixation target in a random fashion. Fixation behavior was quantified by calculating the bivariate contour ellipse area (BCEA) and the frequency of deviation from the fixation target. The BCEAs (deg2) of Point, Cross, and Ring targets were 1.11, 1.46, and 2.02, respectively. In all cases, BCEA increased significantly with increasing fixation target size (p < 0.05). The logarithmic value of BCEA demonstrated the same tendency (p < 0.05). A positive correlation was identified between fixation behavior and threshold variability for the Point and Cross targets (ρ = 0.413–0.534, p < 0.05). Fixation behavior increased with increasing fixation target size. Moreover, a larger fixation behavior tended to be associated with a higher threshold variability. A small fixation target is recommended during the visual field test.

Fixation Location and Stability Using the MP-1 Microperimeter in Stargardt Disease: ProgStar Report No. 3

To determine fixation location and fixation stability in Stargardt disease (STGD1) and their association with best-corrected visual acuity (BCVA). Cross-sectional analysis within the multicenter, prospective ProgStar study. A total of 238 patients and 440 eyes with ABCA4-related STGD1. Patients underwent testing with the Nidek MP-1 microperimeter (Nidek Technologies Inc., Gamagōri, Japan). Fixation location was expressed as the eccentricity of the preferred retinal locus (PRL) from the anatomic fovea, fixation stability was expressed as the bivariate contour ellipse area (BCEA), and BCVA was expressed as Early Treatment Diabetic Retinopathy Study (ETDRS) letters. Linear models with generalized estimating equations were used for statistical analysis while accounting for between-eye correlations. Fixation location and fixation stability. Median PRL eccentricity from the fovea was 6° (mean, 6.3°; range, 0°-25°) and median BCEA was 6.31°2 (mean, 12.31°2; range, 0.03°2-365.63°2). Each year of later onset of symptoms of STGD1 was associated with 0.14° more central fixation location (P < 0.0001), but not with fixation stability (P= 0.53). A single linear model best described the relationship between fixation location and BCVA: 1° farther PRL eccentricity was associated with a 2.3-letter loss of BCVA (P < 0.0001). A piecewise linear model best described the relationship between fixation stability and BCVA: for a BCEA less than 2.8°2, an increase in BCEA by 1°2 was associated with a 10.5-letter (ETDRS) lower BCVA (P < 0.0001). For a BCEA 2.8°2 or more, an increase in BCEA by 1°2 was associated with a 0.036-letter (ETDRS) lower BCVA (P= 0.0234). Pearson correlation coefficients between patients' right and left eyes were 0.89 (P < 0.0001) for fixation location and 0.25 (P= 0.0006) for fixation stability. After 10 years of disease duration, 82% of patients had eccentric PRLs in both eyes. We provide the first extensive database of continuous fixation parameters in STGD1 and demonstrate their association with vision. These measures allow for a more comprehensive assessment of retinal function and may serve as potential secondary outcome measures for future treatment trials for STGD1 and other macular diseases.

The predictive value of retinal fixation for the visual outcome after anti‐VEGF treatment of diabetic macular oedema with center involvement

PurposeDiabetic macular oedema involving the foveal center can be treated with intra‐vitreal anti‐VEGF injections. However, the beneficial effect of this treatment is not unequivocal and presently no known parameter can differentiate patients who benefit by an improved visual acuity after the treatment from the patients who do not. Therefore, the present study aims to investigate the relation between visual acuity and retinal fixation area as a putative predictive parameter for the visual acuity after anti‐VEGF treatment in a planned prospective study.Methods60 eyes from 30 diabetic patients (mean age 61 years) with clinically significant macular oedema were subjected to examination of fixational eye movements before each of three monthly anti‐VEGF injections and at 1‐ and 4‐month follow‐up. Fixational eye movements were recorded for both eyes during binocular and monocular vision using a video based eye‐tracking system. The fixational saccades and the bivariate contour ellipse area (BCEA) were analyzed using standardized algorithms.ResultsThe data from the baseline examination shows a linear correlation between best‐corrected visual acuity and the retinal fixation area estimated by the monocular bivariate contour ellipse area in the studied eyes (r2 = 0.21, p &lt; 0.01).ConclusionsReduced visual acuity is followed by an increased fixation area in patients with diabetic macular oedema with center involvement. Prospective data will show whether the retinal fixation area can be used as a predictive parameter for the visual prognosis after anti‐VEGF treatment of diabetic macular oedema.

Perceptual Learning in Children With Infantile Nystagmus: Effects on 2D Oculomotor Behavior.

To determine changes in oculomotor behavior after 10 sessions of perceptual learning on a letter discrimination task in children with infantile nystagmus (IN). Children with IN (18 children with idiopathic IN and 18 with oculocutaneous albinism accompanied by IN) aged 6 to 11 years were divided into two training groups matched on diagnosis: an uncrowded training group (n = 18) and a crowded training group (n = 18). Target letters always appeared briefly (500 ms) at an eccentric location, forcing subjects to quickly redirect their gaze. Training occurred twice per week for 5 consecutive weeks (3500 trials total). Norm data and test-retest values were collected from children with normal vision (n = 11). Outcome measures were: nystagmus characteristics (amplitude, frequency, intensity, and the expanded nystagmus acuity function); fixation stability (the bivariate contour ellipse area and foveation time); and saccadic eye movements (latencies and accuracy) made during a simple saccade task and a crowded letter-identification task. After training, saccadic responses of children with IN improved on the saccade task (latencies decreased by 14 ± 4 ms and gains increased by 0.03 ± 0.01), but not on the crowded letter task. There were also no training-induced changes in nystagmus characteristics and fixation stability. Although children with normal vision had shorter latencies in the saccade task (47 ± 14 ms at baseline), test-retest changes in their saccade gains and latencies were almost equal to the training effects observed in children with IN. Our results suggest that the improvement in visual performance after perceptual learning in children with IN is primarily due to improved sensory processing rather than improved two-dimensional oculomotor behavior.

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.

Influence of Target Parameters on Fixation Stability in Normal and Strabismic Monkeys.

PurposeThe purpose of this study was to assess the effect of fixation target parameters on fixation instability in strabismic monkeys.MethodsOne normal and three exotropic monkeys were presented with four differently shaped fixation targets, with three diameters, during monocular or binocular viewing. Fixation targets were white on a black background or vice versa. Binocular eye movements were recorded using the magnetic search coil technique and fixation stability quantified by calculating the bivariate contour ellipse area (BCEA).ResultsFixation instability was greater in all the strabismic monkeys compared with the normal monkey. During monocular viewing, strabismic monkeys showed significantly greater instability in the covered eye compared to the fixating eye. Multifactorial ANOVA suggested statistically significant target parameter influences, although effect sizes were small. Thus, a disk-shaped target resulted in greater instability than other target shapes in the viewing eyes of the normal monkey and two of three strabismic monkeys. A similar target-shape effect was also observed in the covered eye. Least instability was elicited with a 0.5° target in the normal monkey and a 1.0° target in the strabismic monkeys, both in the viewing and the covered eye. Target/background polarity effects were idiosyncratic. In strabismic monkeys, stability of the fixating eye during binocular viewing was not different from the stability of the same eye during monocular viewing.ConclusionsAbnormal drifts and nystagmus contribute to increased fixation instability in strabismic monkeys. Target parameters (shape and size) that influence fixation stability in a normal animal also affected fixation stability in our sample of strabismic monkeys.

Fixation Improvement through Biofeedback Rehabilitation in Stargardt Disease.

Stargardt disease is the most common hereditary macular degeneration in juveniles. It is characterized by macular dystrophy associated with loss of central vision in the first or second decade of life, a “beaten-metal” appearance in the fovea or parafoveal region, yellowish flecks around the macula or in posterior area of the retina, progressive atrophy of the bilateral foveal retinal pigment epithelium, and the “dark choroid” sign on fundus fluorescein angiography in most cases. We report a case of Stargardt disease in a 26-year-old Caucasian female submitted to rehabilitative training with microperimetry MP-1 to find a new preferred retinal locus (PRL) and to train her to better her quality of life. Best corrected visual acuity, mean retinal sensitivity, fixation, bivariate contour ellipse area, and speed reading were evaluated before and after the training and results were discussed.

Fixation pattern analysis with microperimetry in nystagmus patients

ObjectiveTo assess the usefulness of microperimetry (MP) as an additional objective method for characterizing the fixation pattern in nystagmus. DesignProspective study. ParticipantsFifteen eyes of 8 subjects (age, 12–80 years) with nystagmus from the Lluís Alcanyís Foundation (University of Valencia, Spain) were included. MethodsAll patients had a comprehensive ophthalmologic examination including a microperimetric examination (MAIA, CenterVue, Padova, Italy). The following microperimetric parameters were evaluated: average threshold (AT), macular integrity index (MI), fixating points within a circle of 1° (P1) and 2° of radius (P2), bivariate contour ellipse area (BCEA) considering 63% and 95% of fixating points, and horizontal and vertical axes of that ellipse. ResultsIn monocular conditions, 6 eyes showed a fixation classified as stable, 6 eyes showed a relatively unstable fixation, and 3 eyes showed an unstable fixation. Statistically significant differences were found between the horizontal and vertical components of movement (p = 0.001), as well as in their ranges (p < 0.001). Intereye comparison showed differences between eyes in some subjects, but only statistically significant differences were found in the fixation coordinates X and Y (p < 0.001). No significant intereye differences were found between microperimetric parameters. Between monocular and binocular conditions, statistically significant differences in the X and Y coordinates were found in all eyes (p < 0.02) except one. No significant differences were found between MP parameters for monocular or binocular conditions. Strong correlations of corrected distance visual acuity (CDVA) with AT (r = 0.812, p = 0.014), MI (r = –0.812, p = 0.014), P1 (r = 0.729, p = 0.002), horizontal diameter of BCEA (r = –0.700, p = 0.004), and X range (r = –0.722, p = 0.005) were found. ConclusionsMP seems to be a useful technology for the characterization of the fixation pattern in nystagmus, which seems to be related to the level of visual acuity achieved by the patient.

Reliability and Intersession Agreement of Microperimetric and Fixation Measurements Obtained with a New Microperimeter in Normal Eyes

Purpose: To evaluate the reliability and intersession agreement of measurements of retinal sensitivity as well as of the fixation pattern obtained in healthy eyes with a microperimeter integrating the mechanism of the scanning laser ophthalmoscope (SLO) with the static perimetry.Methods: This study included a sample of 44 healthy eyes of 44 subjects of a mean age of 27.0 ± 8.5 years. In all cases, microperimetric exams with the MAIA system (Centervue, Padova, Italy) were performed in three different sessions to evaluate the intersession repeatability. The consistency of measurements was analyzed by using the Friedman test and by analyzing the correlation between consecutive measurements. Agreement between the first and third sessions was assessed by using the Passing–Bablok regression analysis. The following parameters were analyzed: average threshold (AT), macular integrity (MI) index, fixation indexes P1 and P2, bivariate contour ellipse area (BCEA), major and minor axes of the ellipse and high preferred retinal locus position (PRLh).Results: Not statistically significant differences were found in the evaluated parameters between the three sessions (p ≥ 0.193). The correlation between consecutive measurements was moderate to strong for all parameters evaluated (r ≥ 0.49, p < 0.01), except for the MI and the position of the PRLh (r ≤ 0.305, p ≥ 0.05). The Passing–Bablok regression analysis showed a good agreement between the first and third measurement for all parameters, except for the MI and the position of the PRLh.Conclusion: MAIA MP system is able to provide consistent measurements of AT and fixation in normal subjects. MI and the position of PRLh seem to be the least reliable parameters in this group of patients.

Fixation Stability Measurement Using Two Types of Microperimetry Devices.

We compared the fixation stability measurements obtained with two microperimeters, the Micro Perimeter 1 (MP-1) and the Spectral OCT/SLO (OCT/SLO), in subjects with and without maculopathies. A total of 41 eyes with no known ocular diseases and 45 eyes with maculopathies were enrolled in the study. Both eyes of each participant had a 20-second fixation test using the MP-1 and OCT/SLO. The bivariate contour ellipse area (BCEA) was used for fixation stability evaluation. In the normal group, BCEA was 2.93 ± 0.32 log minarc2 on OCT/SLO and 2.89 ± 0.30 log minarc2 on MP-1. In the maculopathy group, BCEA was 3.05 ± 0.41 log minarc2 on OCT/SLO and 3.15 ± 0.46 log minarc2 on MP-1. There was no statistically significant difference between the BCEA measured by OCT/SLO and by MP-1 in both groups. A moderate correlation was found between the two devices (r = 0.45, P < 0.001). The sample size during the fixation test was 535.5 ± 14.6 pairs of coordinates in the normal group and 530.7 ± 14.9 pairs in the maculopathy group with MP-1, while it was 72.3 ± 6.9 and 59.9 ± 10.1, respectively, with OCT/SLO. This was due to different tracking frequencies between the two microperimeters. Fixation stability assessment yields similar results using the OCT/SLO and MP-1. A major difference in sampling rate between the two microperimeters does not significantly affect BCEA measurements. Fixation stability assessments are comparable and interchangeable between the OCT/SLO and the MP-1.

Microperimetric Biofeedback Training Improved Visual Acuity after Successful Macular Hole Surgery

Purpose. To evaluate the efficacy of setting a preferred retinal locus relocation target (PRT) and performing Macular Integrity Assessment (MAIA) biofeedback training in patients showing insufficient recovery of best corrected visual acuity (BCVA) despite successful closure of an idiopathic macular hole (MH). Methods. Retrospective interventional case series. Nine eyes of 9 consecutive patients with the decimal BCVA of less than 0.6 at more than 3 months after successful MH surgery were included. A PRT was chosen based on MAIA microperimetry and the patients underwent MAIA biofeedback training. BCVA, reading speed, fixation stability, and 63% bivariate contour ellipse area (BCEA) were evaluated before and after the training. Statistical analysis was carried out using paired Student's t-test. Results. PRT was chosen on the nasal side of the closed MH fovea in 8 patients. After the MAIA training, BCVA improved in all patients. The mean logMAR value of BCVA significantly improved from 0.33 to 0.12 (p = 0.007). Reading speed improved in all patients (p = 0.29), fixation stability improved in 5 patients (p = 0.70), and 63% BCEA improved in 7 patients (p = 0.21), although these improvements were not statistically significant. Conclusion. MAIA biofeedback training improved visual acuity in patients with insufficient recovery of BCVA after successful MH surgery.

Eye-Fixation Behavior in Major Depressive Disorder and the Influence of Pharmacological Therapy: A Microperimetric Study

Background: To evaluate retinal function and fixation stability in major depressive disorder (MDD) and the influence of antidepressant therapy, using the MP-1 microperimeter. Methods: 25 patients with MDD (57 ± 13.73 years) and 25 healthy subjects (HS) (56.41 ± 15.73 years) were enrolled. According to the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV), single (296.2) or recurrent episode (296.3) of MDD was included. Retinal sensitivity, fixation stability, and bivariate contour ellipse area (BCEA) were obtained using MP-1. Then patients were divided according to antidepressant therapy: SSRI/SNRI associated with atypical antipsychotic (group A) and SSRI/SNRI monotherapy (group B) and pharmacological washout (group C). Differences between groups were estimated using the Kruskal-Wallis test with post hoc Mann-Whitney analysis. Spearman’s rank correlation was used for comparisons. Results: Mean retinal sensitivity was significantly reduced in the MDD group than HS (P= 0.02). Six (24%) eyes had a relatively unstable fixation, and mean BCEA was larger than control group (P =0.04). The Kruskal-Wallis analysis of variance showed significant differences in log BCEA between groups (P=0.01), but no differences in mean retinal sensitivity between groups (P=0.09). Conclusion: MDD patients showed impairment in retinal sensitivity and fixation stability respect to the HS. Despite these findings, the impairment of fixation stability seems to be related to antidepressant therapy.