Baksoellah Zainab, Lavy Itay, Baydoun Lamis, Hooijmaijers Hilde C M, van Dijk Korine, Melles Gerrit R J
*Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; and †Melles Cornea Clinic Rotterdam, Rotterdam, the Netherlands.
Cornea. 2017 Dec;36(12):1498-1502. doi: 10.1097/ICO.0000000000001345.
To evaluate changes in maximum keratometry (Kmax), corneal higher-order aberrations (HOAs), and densitometry (backscattered light) up to 1 year after UV cross-linking and their possible relation with changes in the visual outcome.
Retrospective cohort study on 18 eyes of 16 patients, who underwent UV cross-linking after the Dresden protocol for progressive keratoconus or ectasia after laser-assisted in situ keratomileusis. Corrected distance visual acuity (CDVA), Scheimpflug-based corneal tomography, mean image brightness (corneal densitometry) from the anterior 120 μm of the midcornea, and posterior 60 μm of the central 6 mm of the cornea, and HOAs were evaluated.
Kmax at 1 month (59.7 ± 6.0D) after UV cross-linking resembled preoperative Kmax (59.3 ± 6.4D, P = 0.368), decreased until 3 months postoperatively (58.3 ± 6.3D, P = 0.002), and stabilized thereafter (P > 0.227). All postoperative corneal densitometry values were higher than preoperative values in all measured depths (P < 0.05). One-month anterior and total corneal HOAs (4.28 ± 1.64 μm and 3.87 ± 1.62 μm, respectively) resembled preoperative values (4.10 ± 1.70 μm and 3.67 ± 1.62 μm, respectively; P > 0.221) and then decreased until 12 months postoperatively (3.86 ± 1.84 μm and 3.40 ± 1.80 μm, respectively; P < 0.005). Thinnest point thickness decreased from before (442 ± 25 μm) to 3 months postoperatively (427 ± 25 μm, P < 0.001), with no difference at 12 months postoperatively compared with preoperative values (437 ± 29 μm, P = 0.149). CDVA and endothelial cell density remained unchanged (P > 0.345 and P > 0.257, respectively). No relations were found between CDVA and the evaluated parameters (P > 0.05).
One year after UV cross-linking, the observation of stable CDVA and thinnest point thickness, together with reduced Kmax suggests no ectasia progression within the study period in these cases. Although HOAs showed a trend toward improvement, corneal densitometry remained elevated.
评估紫外线交联术后长达1年的最大角膜曲率(Kmax)、角膜高阶像差(HOAs)和密度测量(后向散射光)的变化及其与视觉结果变化的可能关系。
对16例患者的18只眼进行回顾性队列研究,这些患者在采用德累斯顿方案进行紫外线交联后,用于治疗进展性圆锥角膜或准分子原位角膜磨镶术后角膜扩张。评估矫正远视力(CDVA)、基于Scheimpflug的角膜断层扫描、角膜中央前120μm和角膜中央6mm后60μm的平均图像亮度(角膜密度测量)以及HOAs。
紫外线交联术后1个月时的Kmax(59.7±6.0D)与术前Kmax(59.3±6.4D,P = 0.368)相似,术后3个月时下降(58.3±6.3D,P = 0.002),此后稳定(P>0.227)。在所有测量深度,所有术后角膜密度测量值均高于术前值(P<0.05)。术后1个月时角膜前表面和全角膜的HOAs(分别为4.28±1.64μm和3.87±1.62μm)与术前值相似(分别为4.10±1.70μm和3.67±1.62μm;P>0.221),然后在术后12个月时下降(分别为3.86±1.84μm和3.40±1.80μm;P<0.005)。最薄点厚度从术前(442±25μm)降至术后3个月(427±25μm,P<0.001),术后12个月与术前值相比无差异(437±29μm,P = 0.149)。CDVA和内皮细胞密度保持不变(分别为P>0.345和P>0.257)。未发现CDVA与评估参数之间存在相关性(P>0.05)。
紫外线交联术后1年,观察到CDVA和最薄点厚度稳定,同时Kmax降低,表明在研究期间这些病例中没有角膜扩张进展。尽管HOAs显示出改善趋势,但角膜密度测量值仍保持升高。