Healey P R, Crowston J G
Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Westmead, NSW 2145, Australia.
Br J Ophthalmol. 2005 Sep;89(9):1152-6. doi: 10.1136/bjo.2005.071753.
Colourless solutions of mitomycin C (MMC) and 5-fluorouracil (5-FU) are widely used during trabeculectomy to inhibit postoperative scarring. The poor visibility of these agents on the eye has several drawbacks including the inability to accurately assess the area of treatment. This study examined the utility of using trypan blue dye to colour antimetabolites used during trabeculectomy and the effect of trypan blue on antimetabolite cytotoxicity in vitro.
For in vitro experiments, MMC (0.4 mg/ml) and 5-FU (25 mg/ml) were reconstituted with or without trypan blue. A lactate dehydrogenase release assay was used to measure drug induced cell death and viable cell number 7 days after treatment. For clinical assessment, trypan blue 0.1% was added to MMC and 5-FU to final concentrations of between 0.01% and 0.05%. The mixture was applied to Tenon's capsule and sclera via pre-wet or into dry 5x8 mm sponges (MMC and 5-FU) for 3 minutes or by direct subconjunctival injection after completion of surgery (5-FU). Twenty two consecutive patients undergoing trabeculectomy either with or without trypan blue were followed for 2 years postoperatively.
The addition of 0.05% trypan blue to MMC or 5-FU did not alter MMC induced cell death or the number of viable fibroblast in vitro. In vivo, trypan blue clearly delineated the antimetabolite treatment area and facilitated control of excess antimetabolite at the wound margins as well as sponge removal. With direct subconjunctival injection, total staining area varied for a given volume with location of the needle tip. Any leakage from the injection site could be easily seen. No adverse effects attributable to trypan blue were found in 2 years of follow up.
Trypan blue permits delineation of antimetabolite/tissue interactions without affecting cytoxicity for the assays investigated. Trypan blue can be used to visualise antimetabolite soaked sponges, estimate treatment area, and show areas of unintended tissue contact during trabeculectomy. The addition of trypan blue to antimetabolites has potential benefits in clinical, research, and teaching aspects of ocular surgery and therapy.
丝裂霉素C（MMC）和5-氟尿嘧啶（5-FU）的无色溶液在小梁切除术中被广泛用于抑制术后瘢痕形成。这些药物在眼部的可视性差有几个缺点，包括无法准确评估治疗区域。本研究探讨了使用台盼蓝染料对小梁切除术中使用的抗代谢药物进行染色的效用，以及台盼蓝对体外抗代谢药物细胞毒性的影响。
在体外实验中，MMC（0.4mg/ml）和5-FU（25mg/ml）分别在添加或不添加台盼蓝的情况下进行重构。使用乳酸脱氢酶释放试验来测量药物处理7天后诱导的细胞死亡和活细胞数量。在临床评估中，将0.1%的台盼蓝添加到MMC和5-FU中，最终浓度为0.01%至0.05%。将混合物通过预湿或放入干燥的5×8mm海绵（MMC和5-FU）中应用于Tenon囊和巩膜3分钟，或在手术完成后通过直接结膜下注射（5-FU）。对22例连续接受小梁切除术的患者进行了术后2年的随访，其中部分患者使用了台盼蓝，部分未使用。
向MMC或5-FU中添加0.05%的台盼蓝不会改变MMC诱导的细胞死亡或体外成纤维细胞的存活数量。在体内，台盼蓝清晰地勾勒出抗代谢药物的治疗区域，并有助于控制伤口边缘多余的抗代谢药物以及取出海绵。通过直接结膜下注射，对于给定体积，总染色面积因针尖位置而异。注射部位的任何渗漏都很容易看到。在2年的随访中未发现与台盼蓝相关的不良反应。
对于所研究的试验，台盼蓝能够勾勒出抗代谢药物/组织的相互作用，而不影响细胞毒性。台盼蓝可用于使抗代谢药物浸泡的海绵可视化、估计治疗区域，并显示小梁切除术中意外的组织接触区域。在眼科手术和治疗的临床、研究及教学方面，向抗代谢药物中添加台盼蓝具有潜在益处。
