Purpose Fixation stability (FS) of the preferred retinal locus (PRL) may be improved by biofeedback fixation training (BFT) with microperimetry. Such training can be done on the patient's PRL or in different retinal loci with better functional characteristics. We studied both options and compared the outcomes. Methods Sixty-seven consecutive patients with bilateral central vision loss, poor FS and visual acuity (VA) lower than 0.3 LogMAR were recruited for BFT with microperimeter. Patients were assigned into 2 groups. In group A, BFT was performed on the patient's spontaneous PRL. In group B, PRL was located between 2 adjacent loci with the highest light sensitivity and the lowest distance from the fovea. Two sets of 12 weekly BFT sessions were performed. Primary outcomes were: FS, VA and reading speed. Results Outcomes were statistically significantly better in group B. Mean percentage of FS at therapy end improved from 32 to 35% for group A and from 40 to 55% in group B. Mean VA improved from 1 to 0.86 in group A and from 1 to 0.84 in group B. Reading speed (wpm) improved from 56 to 58 in group A and from 63 to 89 in group B. Conclusions This study describes a reliable methodology of improving eccentric fixation stability using BFT in microperimetry, when the fixation training locus is individualized as the retinal area with best functional characteristics. Further studies are needed to validate its value in a larger scale of patients, at different stages of the disease, and its persistence over time.

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.

Low vision patients with eccentric viewing (EV) use extrafoveal retinal areas to compensate for the loss of central vision. Such retinal loci are known as the preferred retinal locus (PRL). It is known that EV is accompanied by unstable fixation. Microperimetry systems with biofeedback training have been used as a rehabilitation aid to improve fixation stability in EV patients. Normally, only the best or dominant eye is selected for such rehabilitation. This case report describes the rehabilitation on both eyes by means of PRL relocation with MAIA microperimetry (Centervue, Padova, Italy) with biofeedback training technology of a 74-year-old woman diagnosed with adult pseudovitelliform dystrophy. The patient presented binocularly similar anatomical and functional characteristics with the PRL located over the dystrophic area. At the end of the 3 months rehabilitation period, the PRL was successfully relocated inferiorly from the fovea showing relevant visual acuity improvement.