Supplementary Material for: Ophthalmic symptoms of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency: A report of three cases

Introduction
LCHAD deficiency, typically inherited as a recessive trait, is a genetic condition predominantly observed in Central and Eastern Europe, with birth prevalence in Poland amounting to 1/118,336. In most European countries, e.g., in Poland since 2014, this disorder is included in newborn screening.

Case presentation
This paper presents the ophthalmic symptoms of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency in three pediatric patients. Visual acuity testing, fundus photography, and optical coherence tomography (OCT) were performed and data was collected over several years (2017–2022). In case 1, a female born in 2010, exhibited abnormalities in the central part of the posterior pole, mainly in the macula and included choriocapillaris atrophy, and severe disruption of the outer retinal layer. Case 2, a female born in 2012, presented with progressive short-sightedness and choroid atrophy documented with angio-OCT. Case 3, a male born in 2013, experienced recurrent hospitalizations due to metabolic decompensations, and presented with mild myopia, thinning of the choroid layer and slight pigment dispersion with macular sparing.

Conclusion
The main ophthalmic symptoms of LCHAD deficiency were choroidal atrophy, disorganization of the outer retinal layer, and myopia. Choroidal atrophy and pigment dispersion were consistently the earliest signs of LCHAD-associated chorioretinopathy. Although the progression of chorioretinopathy in each case resulted from metabolic decompensation, one documented case revealed that not every metabolic crisis results in ophthalmological changes. Nonetheless, strict adherence to a low-fat, high-carbohydrate diet remains crucial to prevent gradual deterioration and vision loss.

引言
长链3-羟酰基辅酶A脱氢酶（long-chain 3-hydroxyacyl-CoA dehydrogenase, LCHAD）缺乏症通常以常染色体隐性遗传方式传递，是一种主要流行于中欧与东欧地区的遗传性代谢病，波兰的出生患病率为1/118336。目前多数欧洲国家已将该疾病纳入新生儿筛查项目，波兰自2014年起开始实施该项筛查。

病例报告
本文报告了3例儿科LCHAD缺乏症患者的眼部临床表现。研究于2017至2022年间对受试者开展了视力检查、眼底摄影及光学相干断层扫描（optical coherence tomography, OCT）并收集了该时段的随访数据。病例1为2010年出生的女性患者，后极部中央区域（主要累及黄斑区）存在异常，表现为脉络膜毛细血管萎缩及视网膜外层结构严重破坏。病例2为2012年出生的女性患者，呈现进行性近视，经血管光学相干断层扫描（angio-OCT）证实存在脉络膜萎缩。病例3为2013年出生的男性患者，因代谢失代偿反复住院，临床表现为轻度近视、脉络膜层变薄及轻度色素弥散，伴黄斑回避。

结论
LCHAD缺乏症的主要眼部表现为脉络膜萎缩、视网膜外层结构紊乱及近视。脉络膜萎缩与色素弥散始终是LCHAD相关性脉络膜视网膜病变的最早体征。尽管所有病例中的脉络膜视网膜病变进展均与代谢失代偿相关，但有1例经记录的病例证实，并非所有代谢危象都会引发眼部病变。尽管如此，严格遵循低脂高碳水化合物饮食对于预防病情逐渐恶化及视力丧失仍至关重要。