目的:Bietti晶体营养不良(BCD)是一种罕见的常染色体隐性遗传性视网膜营养不良,由CYP4V2基因的致病变异体引起,其特征是视网膜上有光泽的黄色沉积物和视网膜色素上皮(RPE)和脉络膜毛细血管的进行性萎缩。本研究的主要目的是描述受BCD影响的患者的光学相干断层扫描血管造影(OCTA)特征。
方法:一名59岁女性经基因证实为BCD,在萎缩性视网膜中进行了完整的OCTA眼科检查,交界区和明显正常的视网膜。在眼底自发荧光(FAF)成像中将脉络膜毛细血管(CC)萎缩的面积与RPE萎缩的面积进行比较。
结果:在萎缩性地区记录了浅层和深层毛细血管丛以及CC水平的严重血管密度(VD)不足,导致交界区域更深,而明显保留的视网膜显示出与对照眼相似的VD值。FAF上的RPE萎缩面积(右眼为55.90mm2,左眼为48.76mm2)大于OCTA成像上的CC萎缩面积(右眼和左眼分别为51.86mm2和42.44mm2)。
结论:我们的研究结果表明,视网膜丛和CC的VD损害是随着RPE的变性而发生的,这表现为与CC萎缩相比,RPE萎缩的面积更大。基于OCTA成像的进一步研究对于增强我们对这种罕见疾病的认识是必要的。
OBJECTIVE: Bietti crystalline dystrophy (BCD) is a rare autosomal recessive retinal dystrophy caused by pathogenic variants of CYP4V2 gene and characterized by shiny yellow deposits in the retina and progressive atrophy of the retinal pigment epithelium (RPE) and choriocapillaris. The main aim of the present study is to describe the optical coherence tomography angiography (OCTA) characteristics of a patient affected by BCD.
METHODS: A 59-years-old female with genetically confirmed BCD underwent an ophthalmological examination complete of OCTA performed in the atrophic retina, the junctional zone and the apparently normal retina. The area of choriocapillaris (CC) atrophy was compared to the area of RPE atrophy on fundus autofluorescence (FAF) imaging.
RESULTS: A severe vessel density (VD) deficit at the level of superficial and deep capillary plexa as well as CC was registered in atrophic areas, which resulted deeper with respect to the junctional area, whereas the apparently preserved retina revealed VD values similar to that of control eyes. The area of RPE atrophy on FAF was larger (55.90 mm2 in right eye and 48.76 mm2 in left eye) than the area of CC atrophy on OCTA imaging (51.86 mm2 and 42.44 mm2 respectively in right and left eye).
CONCLUSIONS: Our findings suggest that VD impairment of retinal plexa and CC follows the degeneration of RPE as demonstrated by the greater size of the area of RPE atrophy compared to CC atrophy. Further investigations based on OCTA imaging are necessary to enhance our knowledge of this rare disease.