To evaluate the efficacy of the early start of a low fat, high carbohydrate diet in preventing progression of pigmentary retinopathy, a characteristic feature of long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiency, a mitochondrial long-chain fatty acid β-oxidation defect.Methods
13 Finnish patients with early diagnosis of LCHAD deficiency caused by the homozygous G1528C/Q510Q common mutation, were followed up to 20 years (median 6 y). An ophthalmic examination was performed every 1-2 years including BCVA, colour vision, axial length, fundus colour photography, OCT, and ERG.Results
11 out of 13 patients had mild pigmentary changes already in their first ocular exam (median age of 6 mos), while 2 had pale newborn retina. The initial fundus changes were most often pigment granularity in the posterior pole, hyperpigmented macula and pale fundus. In 12 patients, with good compliance of the dietary therapy, the pigmentary changes progressed only mildly or not at all, re-maining at stage II of retinopathy with no atrophy and visual compromise. The only patient with an overall poor outcome, had progression of the chorioretinopathy to stage III, presenting atrophy in the posterior pole with relative sparing of the macula and far periphery.Conclusion
Our long-term ocular follow-up data are promising and suggest that the low-fat, high-carbohydrate diet started during the first months of life may delay or even halt the progression of the pigmentary retinopathy and possibly prevents the visual handicap in LCHAD deficiency.