BACKGROUND Presence of corneal cystine crystals is the main ocular manifestation of cystinosis, although controversial findings concerning the corneal layer with the highest density have been reported. The aim of this study was the analysis of the characteristics of crystal arrangement in different corneal layers and the assessment of corneal morphological changes with age. METHODS A cross sectional study was carried out in three children and three adults who had nephropathic cystinosis and corneal cystine depositions. All patients underwent a comprehensive ophthalmological examination including best corrected distance visual acuity, slit-lamp examination, in vivo confocal microscopy and anterior segment optical coherence tomography. An evaluation of the depth of crystal deposits and crystal density in different corneal layers was also performed. Due to the low number of subjects no statistical comparison was performed. RESULTS Anterior segment optical coherence tomography images revealed deposition of hyperreflective crystals from limbus to limbus in each patient. Crystals appeared as randomly oriented hyperreflective, elongated structures on in vivo confocal microscopy images in all corneal layers except the endothelium. In children the deposits occurred predominantly in the anterior stroma, while in adults, the crystals were mostly localized in the posterior corneal stroma with the depth of crystal deposition showing an increasing tendency with age (mean depth of crystal density was 353.17 ± 49.23 μm in children and it was 555.75 ± 25.27 μm in adults). Mean crystal density of the epithelium was 1.47 ± 1.17 (median: 1.5; interquartile range: 0.3-2.4). Mean crystal density of the anterior and posterior stroma of children and adults was 3.37 ± 0.34 (median: 3.4; interquartile range: 3.25-3.55) vs. 1.23 ± 0.23 (median: 1.2; interquartile range: 1.05-1.35) and 0.76 ± 0.49 (median: 0.7; interquartile range: 0.4-1.15) vs. 3.63 ± 0.29 (median: 3.7; interquartile range: 3.45-3.8), respectively. Endothelium had intact structure in all cases. Some hexagonal crystals were observed in two subjects. CONCLUSIONS In vivo confocal microscopy and anterior segment optical coherence tomography confirmed an age-related pattern of crystal deposition. In children, crystals tend to locate anteriorly, while in adults, deposits are found posteriorly in corneal stroma.

中文翻译：

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使用体内共聚焦显微镜和前节光学相干断层扫描检查肾病性胱氨酸病中的角膜沉积：年龄相关的横断面研究。

背景技术虽然已经报道了关于具有最高密度的角膜层的有争议的发现，但是角膜胱氨酸晶体的存在是胱氨酸病的主要眼部表现。这项研究的目的是分析不同角膜层中晶体排列的特征，并评估随年龄的角膜形态变化。方法对三名患有肾病性胱氨酸病和角膜胱氨酸沉积的儿童和三名成人进行了横断面研究。所有患者均接受了全面的眼科检查，包括最佳矫正远视力，裂隙灯检查，体内共聚焦显微镜和前节光学相干断层扫描。还对不同角膜层中的晶体沉积深度和晶体密度进行了评估。由于受试者人数少，因此未进行统计比较。结果前段光学相干断层扫描图像显示每例患者从角膜缘到角膜缘沉积了高反射晶体。在体内共聚焦显微镜图像上，除内皮外，所有角膜层中的晶体均表现为随机取向的超反射，细长结构。在儿童中，沉积物主要发生在前间质中，而在成年人中，晶体主要位于后角膜基质中，随着年龄的增长，晶体沉积的深度呈增加趋势（儿童的平均晶体密度为353.17±49.23μm成人为555.75±25.27μm）。上皮的平均晶体密度为1.47±1.17（中位数：1.5；四分位间距：0.3-2.4）。儿童和成人的前，后间质平均晶体密度分别为3.37±0.34（中位数：3.4；四分位数范围：3.25-3.55）和1.23±0.23（中位数：1.2；四分位数范围：1.05-1.35）和0.76±0.49 （中位数：0.7；四分位间距：0.4-1.15）与3.63±0.29（中位数：3.7；四分位间距：3.45-3.8）。在所有情况下，内皮都有完整的结构。在两个受试者中观察到一些六角形晶体。结论体内共聚焦显微镜和前段光学相干断层扫描证实了年龄相关的晶体沉积模式。在儿童中，晶体倾向于位于前方，而在成年人中，晶体位于角膜基质的后方。四分位数范围：1.05-1.35）和0.76±0.49（中位数：0.7；四分位数范围：0.4-1.15）与3.63±0.29（中位数：3.7；四分位数范围：3.45-3.8）。在所有情况下，内皮都有完整的结构。在两个受试者中观察到一些六角形晶体。结论体内共聚焦显微镜和前段光学相干断层扫描证实了年龄相关的晶体沉积模式。在儿童中，晶体倾向于位于前方，而在成年人中，晶体位于角膜基质的后方。四分位数范围：1.05-1.35）和0.76±0.49（中位数：0.7；四分位数范围：0.4-1.15）与3.63±0.29（中位数：3.7；四分位数范围：3.45-3.8）。在所有情况下，内皮都有完整的结构。在两个受试者中观察到一些六角形晶体。结论体内共聚焦显微镜和前段光学相干断层扫描证实了年龄相关的晶体沉积模式。在儿童中，晶体倾向于位于前方，而在成年人中，晶体位于角膜基质的后方。结论体内共聚焦显微镜和前段光学相干断层扫描证实了年龄相关的晶体沉积模式。在儿童中，晶体倾向于位于前方，而在成年人中，晶体位于角膜基质的后方。结论体内共聚焦显微镜和前段光学相干断层扫描证实了年龄相关的晶体沉积模式。在儿童中，晶体倾向于位于前方，而在成年人中，晶体位于角膜基质的后方。