Use of MAIA Microperimetry in Routine Tertiary Retinal Practice

Heather Mack FRANZCO PhD1,2
Jessica Boyle BOrth&OphthSc BHlthSc(Hons)1,3
Meri Vukicevic PhD1,3
Wilson Heriot FRANZCO1,4
1 Eye Surgery Associates, Cabrini Medical Hospital, Malvern, Australia
2 Department of Ophthalmology, University of Melbourne, Melbourne, Australia
3 Department of Community & Clinical Allied Health, La Trobe University, Melbourne, Australia
4 Centre for Eye Research, East Melbourne, Australia

Background: Microperimetry is well established as a psychophysical outcome measure in clinical trials and is increasingly used in routine retinal practice for patients with visual symptoms. However, there is sparse evidence indicating the value of microperimetry in the clinical setting as distinct from the research setting. The aim of this study was to describe the usefulness of the MAIA microperimeter in tertiary retinal practice.

Method: A total of 80 eyes of 48 patients presenting to a private tertiary medical and surgical retina practice were retrospectively reviewed. Sixty-two eyes had retinal or macular pathology and nine had no retinal or macular pathology clinically present. Diagnosis classification information was missing for nine eyes. Visual acuity, clinical examination, optical coherence tomography (OCT) and Macular Integrity Assessment (MAIA) microperimetry were performed, and presenting symptoms recorded. Primary outcome measures were best corrected visual acuity (BCVA; LogMAR letters), macular integrity index (MII), average threshold sensitivity (ATS; dB) and test duration (minutes). Secondary outcome measures were pattern of visual field loss and fixation stability.

Results: MII was strongly related to BCVA and ATS (Spearman’s rho = -0.305, p = 0.006; r = -0.767, p < 0.0001 respectively). Four groups were identified, including three abnormal groups and one normal group: i) focal scotoma (21 eyes); ii) reduced average threshold with poor fixation (31 eyes); iii) reduced average threshold with normal fixation (20 eyes); and iv) normal (8 eyes). MII (p < 0.0001) and ATS (p < 0.0001) were significantly different between abnormal and normal eyes. Overlap was present in results of abnormal and normal eyes, and no sole microperimetry outcome measure was unequivocally able to distinguish
between the three abnormal groups, or between normal and abnormal eyes.

Conclusions: MAIA MII is strongly related to ATS and BCVA. Different patterns of visual field loss are described, but no single microperimetry parameter distinguished normal from abnormal patients. It is crucial to interpret microperimetry results appropriately in the clinical context.