体外初步分析采用微角膜刀制备的 DSAEK 供体内皮移植物的均匀性、圆度和同心性。

In vitro pilot analysis of uniformity, circularity, and concentricity of DSAEK donor endothelial grafts prepared by a microkeratome.

机构信息

*Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT; †University of Arizona College of Medicine, Tucson, AZ; ‡Wilmer Eye Institute at Johns Hopkins, Baltimore, MD; §Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY; and ¶Department of Ophthalmology, State University of New York Upstate Medical University, Syracuse, NY.

出版信息

Cornea. 2014 Feb;33(2):191-6. doi: 10.1097/ICO.0000000000000031.

DOI:10.1097/ICO.0000000000000031

PMID:24326334

Abstract

PURPOSE

The aim of this study was to analyze Descemet stripping automated endothelial keratoplasty donor endothelial grafts, prepared by using a microkeratome, in terms of uniformity, circularity, and concentricity.

METHODS

In this pilot study, 12 human donor corneas were prepared by means of a microkeratome and imaged using the Visante anterior segment optical coherence tomography along 4 meridians. The microkeratome enters and exits the corneal tissue at an angle, creating a donor graft bed with a uniform stromal (US) thickness in between the angled edges. We termed the angled portion the "nonuniform stromal transitional annulus" (STA), the point of entry and exit of the microkeratome the "epithelium-to-epithelium" (E-E) diameter, and the length of the US bed the "US" diameter. The E-E and US diameters were measured to create a model of each donor graft, from which circularity and concentricity were calculated. The STA length and height were measured, and the slope was calculated.

RESULTS

The mean E-E diameter was 10.69 ± 0.32 mm (range, 9.46-11.75 mm) and the mean US diameter was 8.96 ± 0.40 mm (range, 7.62-10.28 mm). The microkeratome generated elliptical rather than circular cuts, with a mean eccentricity of 0.34 ± 0.098 (range, 0.22-0.58). Eccentricity values between 0 and 1 represent ellipses, with zero characterizing a circle. The US ellipses and E-E ellipses were not concentric, with a mean deviation of the centers of the shapes of 177.06 ± 92.06 μm (range, 21.95-322.22 μm). The mean STA length was 0.73 ± 0.31 mm (range, 0.25-1.89 mm), the mean height was 0.43 ± 0.08 mm (range, 0.28-0.64 mm), and the mean slope was 34.11 ± 14.00° (range, 8.43-53.67°).

CONCLUSIONS

Microkeratome cuts created nonuniform, noncircular nonconcentric donor grafts. Asymmetry and nonuniformity of donor tissue may help explain suboptimal visual outcomes.

摘要

目的

本研究旨在分析使用微型角膜刀制备的 Descemet 撕囊自动内皮角膜移植供体内皮移植物在均匀性、圆度和同心度方面的情况。

方法

在这项初步研究中，使用微型角膜刀制备 12 个人类供体角膜，并使用 Visante 眼前节光学相干断层扫描仪在 4 条子午线上对其进行成像。微型角膜刀以一定角度切入和离开角膜组织，在角度边缘之间形成具有均匀基质（US）厚度的供体移植物床。我们将角度部分称为“非均匀基质过渡环”（STA），将微型角膜刀的进入和退出点称为“上皮到上皮”（E-E）直径，将 US 床的长度称为“US”直径。测量 E-E 和 US 直径以创建每个供体移植物的模型，从中计算出圆度和同心度。测量 STA 的长度和高度，并计算斜率。

结果

平均 E-E 直径为 10.69 ± 0.32mm（范围为 9.46-11.75mm），平均 US 直径为 8.96 ± 0.40mm（范围为 7.62-10.28mm）。微型角膜刀产生的是椭圆形而不是圆形切口，平均偏心率为 0.34 ± 0.098（范围为 0.22-0.58）。0 到 1 之间的值表示椭圆，零表示圆形。US 椭圆和 E-E 椭圆不同心，形状中心的平均偏差为 177.06 ± 92.06μm（范围为 21.95-322.22μm）。STA 的平均长度为 0.73 ± 0.31mm（范围为 0.25-1.89mm），平均高度为 0.43 ± 0.08mm（范围为 0.28-0.64mm），平均斜率为 34.11 ± 14.00°（范围为 8.43-53.67°）。