Department of Medical-Surgical, Ophthalmology Unit, S. Marta Hospital, Catania University, Catania, Italy.
Cornea. 2010 Jan;29(1):19-25. doi: 10.1097/ICO.0b013e3181ab98ae.
To determine the correlation between corneal shape changes and ultrasound biomicroscopy (UBM) findings at the sclerotomy sites in conventional 20-gauge (G) pars plana vitrectomy (PPV) and 25-G transconjunctival sutureless vitrectomy (TSV) and to compare the effectiveness of the two surgical methods.
Prospective, comparative, observational case series.
Sixty consecutive eyes (60 patients) undergoing primary 3-port PPV. Thirty eyes (30 patients, group 20-G) were treated with 20-G standard PPV and 30 eyes (30 patients, group 25-G) with 25-G TSV. We compared healing of the sclerotomy sites in the two groups. We determined the correlation between corneal shape changes (surgically induced astigmatism) measured by video keratography and the durations of scleral healing cicatrization by UBM within each group.
UBM examination showed that the 20-G sclerotomy sites took about 8 weeks to heal, measured as complete opposition, whereas healing of the 25-G TSV sclerotomy was quite rapid, with complete scleral opposition in about 4 weeks. Corneal topography analysis showed, during the early postoperative period, a surgically induced steepening of the cornea in both groups (20 G, 3.08 +/- 0.56 diopters and 25 G, 0.805 +/- 0.61 diopters, P < 0.001, Mann-Whitney test), which then decreased gradually, recovering to the preoperative level within two months in group 20 G (P > 0.05) and 1 month in group 25 G (P > 0.05). We found a strong statistical correlation between the mean surgically induced keratometric astigmatism and the mean UBM measures of scleral healing (r = 0.99 for group 20 G and r = 0.97 for group 25 G).
After PPV, astigmatic changes are especially significant in the early postoperative period in 20-G group; the 25-G TSV system results in faster reduction of surgically induced keratometric astigmatism because of rapid cicatrization of the sclerotomy sites.
确定在传统 20G（G）经睫状体平坦部玻璃体切割术（PPV）和 25G 经结膜无缝合玻璃体切割术（TSV）中，巩膜切口处角膜形状变化与超声生物显微镜（UBM）检查结果之间的相关性，并比较两种手术方法的效果。
前瞻性、对照、观察性病例系列。
连续 60 只眼（60 例患者）行原发性 3 端口 PPV。30 只眼（30 例患者，20-G 组）行 20-G 标准 PPV，30 只眼（30 例患者，25-G 组）行 25-G TSV。我们比较了两组巩膜切口的愈合情况。我们在每组内确定了通过视频角膜地形图测量的角膜形状变化（手术诱导散光）与 UBM 测量的巩膜愈合瘢痕形成时间之间的相关性。
UBM 检查显示，20-G 巩膜切口需要约 8 周时间才能愈合，表现为完全对合，而 25-G TSV 巩膜切口愈合非常迅速，约 4 周即可完全对合。角膜地形图分析显示，在术后早期，两组均出现角膜手术诱导性变陡（20-G 组为 3.08+/-0.56 屈光度，25-G 组为 0.805+/-0.61 屈光度，P<0.001，Mann-Whitney 检验），然后逐渐下降，20-G 组在两个月内恢复到术前水平（P>0.05），25-G 组在 1 个月内恢复到术前水平（P>0.05）。我们发现平均手术诱导的角膜散光与平均 UBM 测量的巩膜愈合之间存在很强的统计学相关性（20-G 组 r=0.99，25-G 组 r=0.97）。
PPV 后，20-G 组在术后早期散光变化尤其显著；25-G TSV 系统由于巩膜切口快速愈合，导致手术诱导的角膜散光迅速减少。
