局限性黄斑转位手术的实验研究

目的 建立局限性黄斑转位手术(limited macular translocation, LMT)的兔眼模型，探讨LMT的并发症、适应证及可预测性。 方法 建立LMT的兔眼模型，并按巩膜缩短距离分为4.5、3.5 mm组，观察视网膜转位效果（距离和方向）及并发症；手术后1个月松解4只兔眼的巩膜缩短缝线，并在松解巩膜缩短缝线前后测量角膜地形图以了解角膜散光的变化；视网膜光凝标记4只有色素兔的视网膜和脉络膜，观察光凝造成的神经视网膜-视网膜色素上皮(retinal pigment epithelium, RPE)粘连对手术效果的影响。 结果 LMT的成功率达86.7%，视网膜转位距离为610～2 690 μm,平均转位距离为(1 395±636) μm，视网膜转位角度α为10～38°,平均转位角度为(22.7±8.3)°，巩膜缩短4.5、3.5 mm组的转位距离差异无显著性意义(P＞0.05)。并发症主要有眼内出血、视网膜裂孔、角膜散光等。巩膜缩短缝线松解后角膜散光变小、变规则，而视网膜转位未回退。视网膜光凝造成的神经视网膜-RPE粘连使神经视网膜难以分离，易产生视网膜裂孔。 结论 LMT的兔眼模型获得了解剖转位成功，并发症较少；视网膜转位方向是影响手术效果的重要因素；巩膜缩短缝线松解手术可以安全、有效地减轻手术后的角膜散光；对已行黄斑区、黄斑旁区视网膜光凝的患者要慎行黄斑转位术。 (中华眼底病杂志, 2002, 18: 203-207)

Experimental study of limited macular translocation

Objective By using a newly developed animal model of limited macular translocation (LMT) in rabbit eyes, to explore the complications,indications and predictability of LMT. Methods LMT models were performed in 15 rabbit eyes, and were divided into 4.5 mm group and 3.5 mm group by the length of scleral shortening.The effect of retinal translocation (distance and direction) and its complications were analyzed. In a separated group, postoperative corneal astigmatism was studied after release of scleral shortening suture 1 month after LMT. In order to study the impact of neuroretina-retinal pigment epithelium (RPE) adhesion on LMT, retinas and choroids in 4 pigmented rabbit eyes were pretreated with photocoagulation. Results Success rate of LMT was 86.7%. In these cases, retinal translocations were achieved［(distance of 610 to 2690 μm, AKx-]±s=(1395±636)μm; translocation angle α of 10-38°, AKx-]±s=(22.7±8.3) °］. The difference in scleral shortening between 4.5 mm and 3.5 mm groups did not significantly influence the final translocation. Major complications of LMT included intraocular bleeding, retinal break, and corneal astigmatism. Release of scleral shortening suture reduced corneal astigmatism and made it more regular, meanwhile, retinal translocation did not regress. The neuroretina-RPE adhesion induced by retinal photocoagulation made neuroretinal hydrodissection difficult, and led to retinal break readily. Conclusion Sufficient LMT models in rabbit eye were obtained with few postoperative complications. Direction of retinal translocation is an important factor influencing the effect of LMT, except for distance. Release of scleral shortening suture can effectively reduce corneal astigmatism without causing regression of retinal translocation. For the patients with a history of macular or para-macular photocoagulation, LMT should be performed carefully. (Chin J Ocul Fundus Dis, 2002, 18: 203-207)