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

Abstract

Purpose: The ''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. Methods: Total and Pattern Deviation probability levels, using two different methods, were derived at each of 40 stimulus locations, within 78 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. Results: Sensitivities 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. Conclusions: The 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 Relevance: The 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.

Multicenter normative data for mesopic microperimetry

“…However, our analysis and previous studies have revealed that aging and eccentricity have a significant impact on mesopic retinal sensitivity. 17,18 Based on our findings, we predict for example that around half of the sensitivity measurements at 10° eccentricity will fall below 25 dB in healthy individuals at the age of 75.…”

“…6,7 To date, most work seeking to establish such normative data for microperimetry is based on separate analyses of a pre-defined test locations from standardized stimulus patterns. 17,18 One previous publication by Denniss and Astle 19 proposed using spatial interpolation to obtain normative data from specific retinal locations.…”

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

“…Other studies have also reported MAIA values from healthy eyes as control groups in their studies. 4,8,19,25,33 The mean MS reported ranges from 24.9 to 29.5 dB. It is important to note that direct comparing of MS values reported by different groups to our data is not appropriate as the test grids differ.…”

Clinical Perspectives and Trends: Microperimetry as a Trial Endpoint in Retinal Disease

“…There have already been explicit attempts to replicate SAP visual field indices in retinal conditions using MP data. Pattern deviation, total deviation, mean defect, mean deviation, pattern standard deviation, and loss variance have been evaluated in recent studies [76, 180]. Cluster analysis has also been used to describe disease-specific patterns of visual field defects [180].…”

“…The S-MAIA manual states that fixation losses over 30% are unreliable. Published reports differ according to the level of fixation losses deemed tolerable, with research groups defining their own cut-offs, such as 15, 25, and 33% [74-76]. Given the small number of catch trials presented, 1 or 2 accidental button presses may be enough to classify an examination as unreliable.…”