Kaup Soujanya, Shivalli Siddharudha, Ks Divyalakshmi, Arunachalam Cynthia, Varghese Rejitha Chinnu
Department of Ophthalmology, Yenepoya Medical College, Yenepoya University, Mangalore, Karnataka, India.
Department of Community Medicine, Yenepoya Medical College, Yenepoya University, Mangalore, Karnataka, India.
BMJ Open. 2016 Sep 29;6(9):e012024. doi: 10.1136/bmjopen-2016-012024.
Corneal endothelial damage following phacoemulsification is still one of the major concerns of modern day cataract surgery. Although many techniques have been proposed, the risks of posterior capsular rupture and corneal endothelium damage persist. In theory, damage to the corneal endothelium is minimised by delivering the lowest phaco energy only in the direction necessary to emulsify the lens nucleus. Hence, it is believed that the bevel of the needle should be turned towards the nucleus or the nuclear fragment (ie, bevel-down. However, there is a difference of opinion among ophthalmologists with reference to the phaco tip's position (bevel-up vs bevel-down) during phacoemulsification. This subject has not been extensively studied earlier.
This is a prospective, triple-blinded (trial participant, outcome assessor and the data analyst), randomised controlled trial with 2 parallel groups and with an allocation ratio of 1:1. It will be conducted in a tertiary care hospital, Mangaluru, India. The objective is to compare the postoperative central corneal thickness changes between the bevel-up and bevel-down techniques of phacoemulsification. Patients aged >18 years with immature cataract undergoing phacoemulsification will be selected for the study. The important exclusion criteria are the history of previous significant ocular trauma or intraocular surgery, corneal pathology, pseudoexfoliation syndrome, intraocular inflammation, a preoperative fully dilated pupil <6 mm, anterior chamber depth <2.5 mm and nuclear sclerosis grade >4. After randomisation, patients will undergo phacoemulsification surgery either by a bevel-up or bevel-down procedure. With an estimated power of 80%, the calculated sample size is 55 patients in each group. The recruitment will start from April 2016.
Yenepoya University Ethics Committee, India has approved the study protocol (YUEC/148/2016 on 18 February 2016). It complies with the Declaration of Helsinki, local laws and the International Council for Harmonization-good clinical practices.
CTRI/2016/02/006691; Pre-results.
白内障超声乳化术后的角膜内皮损伤仍是现代白内障手术的主要关注点之一。尽管已经提出了许多技术，但后囊膜破裂和角膜内皮损伤的风险依然存在。理论上，仅在乳化晶状体核所需的方向上施加最低的超声能量，可将角膜内皮的损伤降至最低。因此，人们认为针头的斜面应朝向晶状体核或核碎片（即斜面朝下）。然而，在白内障超声乳化过程中，眼科医生对于超声乳化头的位置（斜面朝上与斜面朝下）存在不同意见。此前该主题尚未得到广泛研究。
这是一项前瞻性、三盲（试验参与者、结果评估者和数据分析师）、随机对照试验，设有2个平行组，分配比例为1:1。该试验将在印度芒格洛尔的一家三级护理医院进行。目的是比较白内障超声乳化手术中斜面朝上与斜面朝下技术术后中央角膜厚度的变化。年龄大于18岁且患有未成熟白内障并接受超声乳化手术的患者将被选入本研究。重要的排除标准包括既往有严重眼外伤或眼内手术史、角膜病变、假性剥脱综合征、眼内炎症、术前完全散大瞳孔<6mm、前房深度<2.5mm以及核硬化分级>4级。随机分组后，患者将接受斜面朝上或斜面朝下的超声乳化手术。估计检验效能为80%，计算得出每组样本量为55例患者。招募工作将于2016年4月开始。
印度耶内波亚大学伦理委员会已批准该研究方案（2016年2月18日批准号为YUEC/148/2016）。该研究符合《赫尔辛基宣言》以及当地法律和国际协调理事会的良好临床实践规范。
CTRI/2016/02/006691；预结果。
