Purchase this article with an account.
Satoshi Ishiko, Tomoko Mase, Eiichi Sato, Kazuhiro Sugawara, Hideo Mukai, Hisashi Kataoka, Akitoshi Yoshida; Effect of background brightness on preferred retinal loci. Invest. Ophthalmol. Vis. Sci. 2017;58(8):3282.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Evaluation of the preferred retinal loci (PRL) would be useful for low-vision care and can be performed by microperimetry (MP). However, the background brightness for the MP examination is much lower than the ambient light. We performed a cross-sectional, observational clinical study to evaluate the effect of background brightness on the PRL in patients with age-related macular degeneration (AMD).
The study included 21 eyes of 21 patients (2 women, 19 men; mean age, 72.4±6.1 years) with AMD and visual acuity (VA) levels of 0.3 or lower. MP was performed to evaluate the PRL and scotoma under the conventional background brightness of 10 cd/m2. We developed a new device to evaluate the PRL under a higher background brightness of 650 cd/m2. A cross-shaped fixation target was used; in both instruments, the length was set to 3 degrees and the width to 0.3 degree.
In patients with VA levels over 0.1, the PRLs under the different brightnesses differed in one (12.5%) of eight eyes in the central or paracentral (within a 4-degree circular area from the fovea) fixation group (counting fingers) evaluated by MP and in two (66.7%) of three eyes in the eccentric fixation group. In patients with VA levels of 0.1 or lower, the PRLs differed in one (25%) of four eyes and six (100%) of six eyes, respectively, a difference that reached significance (p<0.05 by analysis of variance). Some patients had a PRL with the bright background within the deep scotomatous area evaluated by MP.
PRLs differed under different brightnesses, especially in eyes with lower VA and with eccentric fixation evaluated by MP under conventional background brightness. Inconsistencies in the PRL between the two lighting conditions might occur depending on the residual macular function. It might be more beneficial to evaluate PRLs under brighter background conditions such as in ambient light when performing a low-vision care for patients with AMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only