Abstract
Purpose: :
Neovascular Age-related Macular Degeneration (nvAMD) is the commonest cause of visual loss in the Western World. Microperimetry, which assesses sensitivity of the central retina and allows automated functional analysis of the macula, is not currently in routine use in assessment of nvAMD patients. The Macular Integrity Assessment (MAIA) device, which utilises SLO technology, is a 3rd generation microperimetry device which has recently become available for clinical use. A pilot study was conducted to provide a preliminary assessment of its value in monitoring progress and assess any potential correlations with visual acuity and OCT findings in eyes treated with ranibizumab for nvAMD.
Methods: :
Patients attending the nvAMD Clinic between February and August 2010 were considered for inclusion in this study. All patients had previously been treated with intravitreal ranibizumab and were in the maintenance phase of therapy. Eyes that had significant media opacities were excluded. All patients underwent clinical assessment which included best corrected VA, fundal examination, OCT, and MAIA microperimetry. Intravitreal ranibizumab was administered as clinically necessary. Threshold sensitivity (TS) and fixation stability analysis (FS) from microperimetry were compared with OCT findings. For this case series, patients were included only if they had at least 3 measurements repeated at minimum intervals of 1 month or more.
Results: :
21 eyes of 14 patients (6 male, 8 female) were included in the study. Of 21 eyes, 17 eyes had stable OCT findings and central retinal thickness variability <50 microns. In these eyes, TS was unchanged from baseline in 15/17 eyes. However FS improved in 5 patients, worsened in 6 patients, and remained stable in 6 patients. In 2/21 eyes that worsened over the study period on OCT, TS and FS worsened. In 2/21 eyes that improved over the study period, TS was unchanged but FS improved in 1 eye and remained stable in 1 eye.
Conclusions: :
Threshold sensitivity on microperimetry correlates well with anatomical macular integrity in treated nvAMD patients. In eyes with stable nvAMD, TS remains stable but FS may improve, worsen or remain unchanged. Changes in FS may represent retinal remodelling or subclinical worsening of the disease process and this warrants further investigation.
Keywords: age-related macular degeneration • perimetry