Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Cornea. 2013 Mar;32(3):296-300. doi: 10.1097/ICO.0b013e31824a2288.
To determine the minimum depth of phototherapeutic keratectomy (PTK) required for diffuse haze removal in granular corneal dystrophy type 2 and to determine whether Fourier domain optical coherence tomography (FD-OCT) can be an effective technique for predicting the exact required depth of ablation.
The depth of ablation used for diffuse stromal haze removal was evaluated with the slit lamp and serially taken photographs during the PTK procedure. The depth of diffuse haze was measured preoperatively using FD-OCT.
Forty-three eyes of 30 patients were included in this study. The mean age of the patients was 62.0 ± 8.4 years. The mean depth of PTK required was 43.7 ± 6.2 μm (range, 31-59 μm). The mean follow-up period for 29 eyes of 22 patients, who had follow-up periods of more than 6 months, was 21.0 ± 12.0 months. The mean best spectacle-corrected visual acuity of these 29 eyes was 0.43 ± 0.15 preoperatively and 0.71 ± 0.16 (P = 0.022) 1 month postoperatively. Of the 43 eyes of 30 patients, FD-OCT was evaluated in 29 eyes of 22 patients. The mean preoperative depth of diffuse haze using FD-OCT was 44.3 ± 6.4 μm. The mean depth of ablation required to remove diffuse stromal haze was 44.5 ± 5.9 μm. The actual ablated depths correlated well with the depth of haze detected by FD-OCT preoperatively (intraclass correlation coefficient = 0.719).
FD-OCT is an accurate method of predicting the depth of PTK required to remove visually significant diffuse haze in patients with granular corneal dystrophy type 2. We advocate the use of slit-lamp biomicroscopy after the initial 30-μm ablation to determine the necessity for any further ablation.
确定 2 型颗粒状角膜营养不良患者行光动力角膜切削术（PTK）以消除弥漫性混浊所需的最小深度，并确定傅里叶域光学相干断层扫描（FD-OCT）是否可作为预测确切消融所需深度的有效技术。
在 PTK 过程中，使用裂隙灯和连续拍摄的照片评估用于消除弥漫性基质混浊的消融深度。术前使用 FD-OCT 测量弥漫性混浊的深度。
本研究纳入 30 例 43 只眼。患者平均年龄为 62.0±8.4 岁。PTK 所需的平均深度为 43.7±6.2μm（范围 31-59μm）。22 例患者中的 29 只眼的随访时间超过 6 个月，平均随访时间为 21.0±12.0 个月。这些 29 只眼中，29 只眼术前最佳矫正视力为 0.43±0.15，术后 1 个月为 0.71±0.16（P=0.022）。在 30 例患者的 43 只眼中，29 只眼的 22 例患者进行了 FD-OCT 评估。术前 FD-OCT 检测到弥漫性混浊的平均深度为 44.3±6.4μm。消除弥漫性基质混浊所需的平均消融深度为 44.5±5.9μm。实际消融深度与术前 FD-OCT 检测到的混浊深度相关性良好（组内相关系数=0.719）。
FD-OCT 是一种准确的方法，可预测 2 型颗粒状角膜营养不良患者消除明显的弥漫性混浊所需的 PTK 深度。我们主张在初始 30μm 消融后使用裂隙灯生物显微镜来确定是否需要进一步消融。
