Interpreting MAIA Microperimetry Using Age- and Retinal Loci-Specific Reference Thresholds

Abstract

Macular Integrity Assessment (MAIA) microperimetry is used widely in clinical trials and routine practice to assess paracentral scotoma. Current interpretation of MAIA is based on an assumed uniform 25 decibel (dB) cutoff for normal function irrespective of subject age and retinal location. We examined this convention by establishing an ageand loci-specific reference in healthy eyes and comparing this to the <25 dB cutoff. Methods: Retrospective MAIA results from healthy eyes were analyzed for prevalence of loci with <25 dB. At each locus, a new reference cutoff was derived from quantile regression of sensitivity against age at the 2.5th percentile. Two clinical cases of serial MAIA testing were analyzed using the new approach and compared to the <25 dB cutoff. Results: Fifty-four and 56 age-matched (range: 16-75 years) healthy eyes underwent small (37 loci) and large (68 loci) grid testing, respectively. Retinal sensitivity <25 dB was found in 5% of the small grid (1998 data points) and 10% of the large grid (3808 data points). These were found predominantly in older subjects and at the central point or in the perifoveal region. Quantile regression at each individual locus showed age-related decline with a median gradient of 0.6 dB/decade. Conclusions: We caution against using <25 dB cutoff in MAIA interpretation and advocate an age-and loci-specific cutoff criterion. Translational Relevance: Our study suggests that MAIA interpretation is influenced by the criterion used for defining abnormal pointwise measurement.

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

“…Bland-Altman analyses showed that for the BE and the WE the bias was −0.13 log deg 2 (95%CI from −0.41 to 0.12), and 0.0 log deg 2 (95%CI from −0.28 to 0.27), respectively. The 95% limits of agreement were large: ±1.09 log deg 2 for the BE and ±1.01 log deg 2 for the WE. A significant correlation between the average and the difference of the first fixations recorded with the two instruments was detected for the BE (r(18) = 0.59, p = 0.007) and for the WE (r(15) = 0.56, p = 0.02), indicating that a proportional bias exists.…”

“…The repeatability did not improve: for the BE, the bias was −0.14 log deg 2 and the 95% limits of agreement were ±1.12 log deg 2 . For the WE, the bias was −0.004 log deg 2 and the 95% limits of agreement were ±1.06 log deg 2 . In addition, the proportional bias persisted: the correlation…”

Localised relative scotoma in cuticular drusen

“…Quantile regression was utilised to establish loci-and age-specific reference from healthy eyes as previously reported [8]. In brief, at each locus, retinal sensitivity was plotted against age, and quantile regression was utilised to establish the 95% prediction interval [12,13].…”

“…Note that the study recruited patients with intermediate AMD, hence the impact of coexisting soft drusen and hyper-pigmentation may have confounded the results. Furthermore, the comparison was not controlled for age and spatial distribution given the normative values for microperimetry sensitivity changes with age [8,9] and retinal eccentricity [8,10] in healthy eyes. Therefore, small but significant functional changes may be masked by analysis of mean sensitivities alone.…”

Microperimetry Hill of Vision and Volumetric Measures of Retinal Sensitivity

“…There are known age-related changes in perimetry. However, investigations into age-related normative values in microperimetry are limited 12 , 13 and therefore are not yet a part of the standard MAIA output. Historically, volumetric data have not been commonly used due to the difficulties in coding custom programs for the task of three-dimensional rendering.…”