Abstract
Purpose:
Fabry disease is a rare X-linked recessive disorder associated with a deficient enzymatic activity of a-galactosidase A. This enzymatic deficit promotes a progressive deposit of glycosphingolipids in the vascular endothelial cells, causing renal failure and ischemic complications.<br /> Using Goldmann kinetic perimeter, Orssaud et all, has reported that 27% of male patients diagnosed with Fabry's disease show an enlarged blind spot, similar to subclinical optic neuropathy. The aim of the present study was to explore the optic nerve capillaries for blood oxygenation in patients with Fabry disease and to compare these results with blood oxygenation values from the optic nerve capillaries of normal and glaucoma patients.
Methods:
<br /> A total of 16 eyes from 8 Fabry patients (4 males, 4 females, of 48 years average age, from 39 to 57) were examined for the present pilot study.<br /> The results for blood oxygenation in the optic nerve capillaries from 35 healthy subjects and 16 eyes of 8 glaucoma patients with low IOP, from the laboratory database, have been also included in the present study, for comparison.<br /> A non-invasive retinal oximeter by a multichannel spectroscopy technique has been used to measure the optic nerve blood oxygenation (Diaconu 2009), from three specific locations of the optic nerve papilla, representing an area of 0.5 mm in diameter.The blood oxygenation and blood volume optical density values were computed using an algorithm proposed by Vucea et all, 2011.
Results:
The results from the healthy subjects demonstrate that the homogeneous blood oxygenation values in the individual optic nerve area are in the range, from 58.5% ± 1.2 to 72.6% ± 1.3. The papilla of the glaucoma subjects could include areas where the blood oxygenation rate is either lower or higher compared to the normal limits.The results from the Fabry patients demonstrate that in some patients, the optic nerve area is not homogeneous for blood oxygenation but values are in the range of normal. What is typical for Fabry patients is that the spectral values data contain a high optical density for blood content, suggesting that the capillaries structures volume in Fabry patients could be larger than normal.
Conclusions:
The results from the present study are in agreement with the proposal of Sher et all, which suggests that local deposition of glycosphingolipid may cause dilatation and instability of the vascular lumen in Fabry patients.