Abstract
Purpose :
Fabry disease is a rare genetic lysosomal storage disorder (1 in 117,000 people) that leads to progressive accumulation of globotriaosylceramide deposits in a variety of cells including cornea which leads to development of cornea verticillata. Not all individuals show a visible deposit and cornea verticillata but have intracellular deposits when examined under a corneal confocal microscope. We sought to investigate if individuals with Fabry disease have decreased contrast sensitivity function when compared to ocular healthy adults.
Methods :
A total of sixty seven individuals were included in the study (32 Fabry and 35 healthy controls). The measurements of distance and near visual acuity, slit lamp examination, anterior and posterior segment photography and optical coherence tomography measurements (both macula and optic nerve) were obtained. Individuals also underwent binocular contrast sensitivity function (CSF) measurement with a portable near Quick CSF (Adaptive Sensory Technology, Boston MA) which uses Bayesian inference and a trial-to-trial information gain strategy to obtain rapid measurements of contrast sensitivity. The CSF was measured with 50 trials and estimates of area under the log CSF (AULCSF), high spatial frequency cutoff (CSF acuity), and contrast sensitivity at 1, 1.5, 3, 6, 12 and 18 cycles per degree (cpd) were obtained.
Results :
The mean age and standard deviation of ocular healthy group and Fabry group was 36.22 SD 6.4 and 37.83 SD 10.6. The mean age and logmar visual acuity distance and near were not significantly different between the groups (Independent samples t-test p=0.54 , 0.07 and 0.08 respectively). The CSF values did not follow a normal distribution (Kolmogorov-Smirnov test p< 0.05). The CSF function at all spatial frequencies were lower in Fabry group compared to the ocular healthy group. The AULCSF and CS at 1, 1.5, 3 and 6 CPD were significantly lower in the Fabry group compared to the ocular healthy group (Mann-Whitney p<0.05). The CSF acuity and CS at 12 and 18 CPD were not significantly different between the groups (Mann-Whitney p>0.05) (see Figure 1)
Conclusions :
The mean CSF at the low and the mid spatial frequencies region is lower in Fabry group compared to the healthy group whereas CSF in high spatial frequencies region and visual acuity are not significantly different. This may in part be responsible for the vision related issues reported by patients with Fabry disease.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.