Abstract：
OBJECTIVE: To report the clinical course and compare the utility of Scheimpflug tomography (ST) and anterior segment optical coherence tomography (AS-OCT) for central corneal thickness (CCT) and corneal densitometry (CD) assessment in patients with corneal crystals owing to nephropathic cystinosis.
METHODS: A retrospective chart analysis of three patients with nephropathic cystinosis and the presence of corneal cystine crystals in both eyes was performed. All patients underwent clinical examination and anterior segment photography, ST, and AS-OCT scans. Corneal densitometry was exported from built-in proprietary software for ST and from custom-made validated software for AS-OCT. Anterior segment optical coherence tomography images were rescaled to grayscale units from 0 (maximum transparency) to 100 (minimum transparency) to match built-in ST densitometry readings. Furthermore, the mean pixel intensity, representative of CD, was calculated from the pixels corresponding to the segmented cornea.
RESULTS: All three patients had pathognomonic cystine crystals deposits in the cornea and were treated with cysteamine medications that resulted in clinical improvement. The CCT measured using ST exhibited a range from 560 to 958 μm. Conversely, when assessed with AS-OCT, the CCT varied within the range of 548 to 610 μm. Both examinations could be performed, but in the more severe cases, AS-OCT showed far greater utility to estimate CD. In four of six eyes examined, ST showed disproportionate CCT values, compared with the AS-OCT, whereas reliable CD measurements were only available in AS-OCT.
CONCLUSIONS: The AS-OCT could be considered a baseline ocular measurement in cystinosis and in the evaluation of disease progression and treatment efficacy.
METHODS: A retrospective chart analysis of three patients with nephropathic cystinosis and the presence of corneal cystine crystals in both eyes was performed. All patients underwent clinical examination and anterior segment photography, ST, and AS-OCT scans. Corneal densitometry was exported from built-in proprietary software for ST and from custom-made validated software for AS-OCT. Anterior segment optical coherence tomography images were rescaled to grayscale units from 0 (maximum transparency) to 100 (minimum transparency) to match built-in ST densitometry readings. Furthermore, the mean pixel intensity, representative of CD, was calculated from the pixels corresponding to the segmented cornea.
RESULTS: All three patients had pathognomonic cystine crystals deposits in the cornea and were treated with cysteamine medications that resulted in clinical improvement. The CCT measured using ST exhibited a range from 560 to 958 μm. Conversely, when assessed with AS-OCT, the CCT varied within the range of 548 to 610 μm. Both examinations could be performed, but in the more severe cases, AS-OCT showed far greater utility to estimate CD. In four of six eyes examined, ST showed disproportionate CCT values, compared with the AS-OCT, whereas reliable CD measurements were only available in AS-OCT.
CONCLUSIONS: The AS-OCT could be considered a baseline ocular measurement in cystinosis and in the evaluation of disease progression and treatment efficacy.
摘要：
目的：报告临床过程，并比较Scheimpflug断层扫描（ST）和眼前节光学相干断层扫描（AS-OCT）在患者中的中央角膜厚度（CCT）和角膜密度测定（CD）评估中的应用肾病性膀胱病导致的角膜晶体。
方法：对3例肾病性膀胱炎患者进行回顾性图表分析，双眼均存在角膜胱氨酸晶体。所有患者均行临床检查和眼前节摄影,ST,和AS-OCT扫描。角膜密度测定从ST的内置专有软件和AS-OCT的定制验证软件导出。将前段光学相干断层扫描图像重新缩放为从0（最大透明度）到100（最小透明度）的灰度单位，以匹配内置的ST密度测定读数。此外，平均像素强度，CD的代表，从对应于分割的角膜的像素计算。
结果：所有3例患者角膜中都有病理性胱氨酸晶体沉积，并接受半胱胺药物治疗，导致临床改善。使用ST测量的CCT表现出560至958μm的范围。相反，当用AS-OCT评估时，CCT在548至610μm的范围内变化。这两种检查都可以进行，但是在更严重的情况下，AS-OCT显示出更大的估计CD的效用。在检查的六只眼睛中有四只,ST显示出不成比例的CCT值，与AS-OCT相比，而可靠的CD测量仅在AS-OCT中可用。
结论：AS-OCT可被认为是对膀胱炎和疾病进展和治疗疗效评估的基线眼部测量。
方法：对3例肾病性膀胱炎患者进行回顾性图表分析，双眼均存在角膜胱氨酸晶体。所有患者均行临床检查和眼前节摄影,ST,和AS-OCT扫描。角膜密度测定从ST的内置专有软件和AS-OCT的定制验证软件导出。将前段光学相干断层扫描图像重新缩放为从0（最大透明度）到100（最小透明度）的灰度单位，以匹配内置的ST密度测定读数。此外，平均像素强度，CD的代表，从对应于分割的角膜的像素计算。
结果：所有3例患者角膜中都有病理性胱氨酸晶体沉积，并接受半胱胺药物治疗，导致临床改善。使用ST测量的CCT表现出560至958μm的范围。相反，当用AS-OCT评估时，CCT在548至610μm的范围内变化。这两种检查都可以进行，但是在更严重的情况下，AS-OCT显示出更大的估计CD的效用。在检查的六只眼睛中有四只,ST显示出不成比例的CCT值，与AS-OCT相比，而可靠的CD测量仅在AS-OCT中可用。
结论：AS-OCT可被认为是对膀胱炎和疾病进展和治疗疗效评估的基线眼部测量。
