Purchase this article with an account.
Rosalia Maria S. Antunes-Foschini, André Messias; Fixation Pattern In Patients With Bilateral Toxoplasmic Macular Retinochoroiditis. Invest. Ophthalmol. Vis. Sci. 2011;52(14):4243.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To study eccentric fixation characteristics in patients with bilateral toxoplasmic macular retinochoroiditis (TMR), and their implications for visual rehabilitation
15 patients (age from 7 to 36; median = 17 years) with bilateral macular retiochoroiditis were included. Best-corrected visual acuity (BCVA), magnification need and text-reading speed with the dominant eye were recorded. Microperimetry (MAIA, Centervue - Padova, Italy) was performed to find the preferred retinal locus (PRL) and the fixation stability index (FSI) (Vision Research 47 (2007) 2076-2085). In addition, 14 eyes from 14 normally sighted subjects in the same age range were evaluated to serve as control group (CTRL).
As expected, mean ± SE BCVA (LogMAR) was better in dominant eyes: 0.82 ± 0.21 (20/50 to 20/250) than in non-dominants: 1.11 ± 0.31 (20/80 to 20/600) (paired t-test; P=0.004). Microperimetry could not be performed in 5 non-dominant eyes, due to non-visualization of fixation target. Eccentric fixation could be observed in all 25 eyes. In 8 out of 25 eyes (32%) the PRL was placed above the macular lesion, in 7 eyes (28%) between lesion and optic nerve, in 8 eyes (32%) temporal, and in 2 eyes (8%) below. There was no significant difference regarding PRL position distribution for dominant and non-dominant eyes (Pearson test, P=0.8508). Text reading speed ranged from 14 to 140 (median = 43) words per minute (wpm) (texts reference = 180.2 wpm (Arq Bras Oftalmol. 2008;71(4):553-8)). Mean FSI was 52.1% for patients and 77.9% for CTRL (t-Test; P<0.05). There was no difference between FSI in dominant or non-dominant eye, or correlation between FSI and BCVA, magnification need or text-reading speed.
Quantification of fixation pattern by microperimetry offers new data about the impact of visual impairment in patients with TMR, and might be useful for setting up rehabilitation strategies. Our data indicate that these patients spontaneously place their PRL preferentially superior, temporal or nasal to the lesion.
This PDF is available to Subscribers Only