Abstract
Abstract: :
Purpose: To examine outcome measures (ophthalmologic, biochemical, neurodevelopmental and growth) in patients with peroxisomal disorders treated with oral DHA. Disorders of peroxisomal biogenesis and beta–oxidation affect early neuroretinal development causing psychomotor retardation and retinopathy leading to blindness. Peroxisomal disorders have an autosomal recessive inheritance and an overall incidence of 1 in 25–50,000. Docosahexanoic acid (DHA) is a polyunsaturated fatty acid localised in neuronal phospholipids and photoreceptor cells of the retina. DHA can also be administered as pure microencapsulated DHA ethyl ester to patients with peroxisomal disorders where there is functional DHA deficiency in the nervous system. We examined the visual findings and the potential role of DHA therapy in a group of pediatric patients with peroxisomal disorders. Methods: Fifty–one patients (48 patients with peroxisomal assembly disorders (PAD) and 3 patients with multifunctional enzyme deficiency 2 (MFE2) were enrolled in a randomised placebo–controlled, double–blind study in which all had ophthalmologic evaluation, fundus photography, electroretinography (ERG) and flash visual–evoked potential (VEP) measurements. The treated group was composed of 14 males and 12 females while the placebo group included 14 males and 11 females. Results: Thirty–five patients (69%) were followed up. There were 12 deaths (24%) before follow up (6 in each group). Five patients were lost to follow up in the treated group. Ocular findings in the patients included cataracts, optic nerve pallor, varying grades of pigmentary retinopathy, indistinct foveae and chorioretinal atrophy. A significant increase in plasma DHA levels was noted in the treated group compared with placebo. Plasma very long chain fatty acid (VLCFA) levels were also increased in the treated group. Conclusions: The administration of oral DHA improves plasma circulating DHA levels but overall clinical improvement could not be clearly demonstrated in this study. No definate evidence of improved or stabilised photoreceptor function seen by electroretinography was observed. In the absence of other treatment and in view of the poor prognosis, DHA therapy may be useful in improving brain and hepatic function. In addition, the early identification of these disorders is critical for prenatal diagnosis and counseling in families with an affected child.
Keywords: retina • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled • retinal degenerations: hereditary