自1967年白内障超声乳化术问世以来，白内障摘除联合人工晶状体植入已成为最常见、最安全、效果最可预测的手术之一[1]。过去，白内障超声乳化术中的流体动力学调节需要高度调节的灌注以及静态气压系统，以产生高灌注和升高的眼压，这通常是生理水平的2到3倍，以防止阻塞后浪涌和前房塌陷[2]。然而，目前有一种趋势，即在更接近生理灌注压的情况下进行白内障手术，这对提高手术效率和保障患者安全具有潜在益处。
白内障手术中高眼压的风险
手术时升高的眼压虽然是暂时的，但对于每位患者而言，都与基础眼压有显著差异。为了追求极致的前房稳定性，这样的手术环境导致眼球处于相对“过度膨胀”的状态。仅仅开启冲洗，眼内结构就会受到影响，巩膜会拉伸、瞳孔会扩张，晶状体-虹膜膈会向后移动。
改善前房稳定性的技术进步
如今，先进的流体系统使人们在手术时能够关注眼压。手术设备可以聚焦并调节流体，在整个手术过程中维持设定的眼压。眼压低至28毫米汞柱时，仍能保持前房稳定，且手术效率不受影响[16、17]。
生理眼压下手术的益处
除了白内障超声乳化设备的进步，与高眼压相比，医学博士 Robert Osher 的“慢动作”白内障超声乳化术采用较低的灌注压和超声能量，已被证明可以提高术后角膜清晰度，同时减少并发症[26]。较低的眼压可将流动湍流降至最低，最终提高角膜安全性。最近的文献显示，这在保护内皮细胞方面具有统计学意义，还能减少术后炎症和角膜水肿[27、28]，在不增加手术时间或超声能量的情况下改善术中前房视野[29、30]。
注意事项和局限性
尽管在生理眼压下手术有诸多优势，但它确实存在一些局限性。较低的眼压设置会减小前房深度，限制手术医生的“操作空间”。在需要额外空间的病例中，如前房不稳定、成熟晶状体膨出或后房压力较高的眼睛，可能需要较高的眼压设置。当在较低眼压下手术时，如果前房稳定性不足，在雕刻和清除皮质阶段可使用23-34mmHg 的“超生理”眼压，在劈核、碎核和超声乳化吸除阶段可使用35-44mmHg 的“亚高”眼压[25]。然而，虽然在传统的较高眼压下，内皮和晶状体之间的术中操作空间看起来更大，因此似乎“更安全”，但新的证据表明，在不改变医生手术效率的情况下，生理眼压下的术后效果不劣于高眼压，甚至更优。
未来展望
对于大多数接受白内障手术的患者而言，高眼压带来的风险，包括炎症持续、内皮损伤和眼部缺血，都支持在生理眼压下进行手术的建议。这种方法对视神经受损的患者，如严重青光眼患者尤为有益，因为对他们来说，前房稳定和避免眼压波动是至关重要的。
参考文献
[1] Kelman CD. Phaco-emulsification and aspiration. a new technique of cataract removal. a preliminary report. Am J Ophthalmol. 1967;64(1):23-35.
[2] Ward MS, Georgescu D, Olson RJ. Effect of bottle height and aspiration rate on postocclusion surge in Infiniti and Millennium peristaltic phacoemulsification machines. J Cataract Refract Surg. 2008;34(8):1400-1402.
[3] Vasavada AR, Praveen MR, Vasavada VA, et al. Impact of high and low aspiration parameters on postoperative outcomes of phacoemulsification: randomized clinical trial. J Cataract Refract Surg. 2010;36(4):588-593. doi:10.1016/j.jcrs.2009.11.009
[4] Vasavada V, Raj SM, Praveen MR, Vasavada AR, Henderson BA, Asnani PK. Real-time dynamic intraocular pressure fluctuations during microcoaxial phacoemulsification using different aspiration flow rates and their impact on early postoperative outcomes: a randomized clinical trial. J Refract Surg. 2014;30(8):534-540. doi:10.3928/1081597X-20140711-06
[5] Suzuki H, Oki K, Shiwa T, Oharazawa H, Takahashi H. Effect of bottle height on the corneal endothelium during phacoemulsification. J Cataract Refract Surg. 2009;35(11):2014-2017. doi:10.1016/j.jcrs.2009.05.057
[6] Vasavada V, Srivastava S, Vasavada V, et al. Impact of fluidic parameters during phacoemulsification on the anterior vitreous face behavior: experimental study. Indian J Ophthalmol. 2019;67(10):1634-1637. doi:10.4103/ijo.IJO_465_19
[7] Findl O, Strenn K, Wolzt M, et al. Effects of changes in intraocular pressure on human ocular haemodynamics. Curr Eye Res. 1997;16(10):1024-1029. doi:10.1076/ceyr.16.10.1024.9024
[8] Chen D, Zhu J, Li J, Ding XX, Lu F, Zhao YE. Effect of simulated dynamic intraocular pressure on retinal thickness measured by optical coherence tomography after cataract surgery. Int J Ophthalmol. 2012;5(6):687-693. doi:10.3980/j.issn.2222-3959.2012.06.07
[9] Pardianto G. Recent awareness and consideration of intraocular pressure fluctuation during eye surgery. JCataract Refract Surg. 2015;41(3):695. doi:10.1016/j.jcrs.2015.01.009
[10] Ding T, Shi DN, Fan X, Zheng MY, Wang W, Qiu WQ. Effect of infusion pressure during cataract surgery on ganglion cells measured using isolated-check visual evoked potential. Int J Ophthalmol. 2018;11(1):58-65. Published 2018 Jan 18. doi:10.18240/ijo.2018.01.11
[11] Takhtaev, YV, Kiseleva TN, Shliakman RB. The effect of preset intraoperative intraocular pressure during phacoemulsification on the blood flow velocity in the central retinal artery. Ophthalmology Journal.2019;12(4):5-12.
[12] Zhao Z, Yu X, Yang X, et al. Elevated intraocular pressure causes cellular and molecular retinal injuries, advocating a more moderate intraocular pressure setting during phacoemulsification surgery. Int Ophthalmol. 2020;40(12):3323-3336. doi:10.1007/s10792-020-01519-w
[13] Hayreh SS. Anterior ischemic optic neuropathy. IV. occurrence after cataract extraction. Arch Ophthalmol. 1980;98(8):1410-1416. doi:10.1001/archopht.1980.01020040262010
[14] Yang HK, Park SJ, Byun SJ, Park KH, Hwang JM. Risk of nonarteritic anterior ischemic optic neuropathy after cataract surgery. Am J Ophthalmol. 2019;207:343-350. doi:10.1016/j.ajo.2019.08.001
[15] Li, ALW, Yuen HKL. Bilateral nonarteritic anterior ischemic optic neuropathy after immediate sequential bilateral cataract surgery. J Cataract Refract Surg. 2021;9(1):1-3. doi:10.1097/j.jcro.0000000000000033
[16] Rauen MP, Joiner H, Kohler RA, O’Connor S. Phacoemulsification using an active fluidics system at physiologic vs high intraocular pressure: impact on anterior and posterior segment physiology. J Cataract Refract Surg. 2024;50(8):822-827. doi:10.1097/j.jcrs.0000000000001457
[17] Suzuki H, Igarashi T, Takahashi H. Effect of a new phacoemulsification and aspiration handpiece on anterior chamber stability. J Cataract Refract Surg. 2023;49(1):91-96. doi:10.1097/j.jcrs.0000000000001071
[18] Han YK, Miller KM. Comparison of vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification systems. J Cataract Refract Surg. 2009;35(8):1424-1429. doi:10.1016/j.jcrs.2009.03.041
[19] Solomon KD, Lorente R, Fanney D, Cionni RJ. Clinical study using a new phacoemulsification system with surgical intraocular pressure control. J Cataract Refract Surg. 2016;42(4):542-549. doi:10.1016/j.jcrs.2016.01.037
[20] Jensen JD, Boulter T, Lambert NG, et al. Intraocular pressure study using monitored forced-infusion system phacoemulsification technology. J Cataract Refract Surg. 2016;42(5):768-771. doi:10.1016/j.jcrs.2016.01.045
[21] Nicoli CM, Dimalanta R, Miller KM. Experimental anterior chamber maintenance in active versus passive phacoemulsification fluidics systems. J Cataract Refract Surg. 2016;42(1):157-162. doi:10.1016/j.jcrs.2015.08.017
[22] Malik PK, Dewan T, Patidar AK, Sain E. Effect of IOP based infusion system with and without balanced phaco tip on cumulative dissipated energy and estimated fluid usage in comparison to gravity fed infusion in torsional phacoemulsification. Eye Vis (Lond). 2017;4:22. doi:10.1186/s40662-017-0087-5
[23] Thorne A, Dyk DW, Fanney D, Miller KM. Phacoemulsifier occlusion break surge volume reduction. J Cataract Refract Surg. 2018;44(12):1491-1496. doi:10.1016/j.jcrs.2018.01.032
[24] Suzuki H, Igarashi T, Takahashi H. Effect of a new phacoemulsification and aspiration handpiece on anterior chamber stability. J Cataract Refract Surg. 2023;49(1):91-96. doi:10.1097/j.jcrs.0000000000001071Parkash RO, Parkash TO. Differential intraocular pressure phacoemulsification. Delhi J Ophthalmol.2024;34(4):250-253.
[25] Parkash RO, Parkash TO. Differential intraocular pressure phacoemulsification. Delhi J Ophthalmol.2024;34(4):250-253.
[26] Osher RH. Slow motion phacoemulsification approach. J Cataract Refract Surg. 1993;19(5):667. doi:10.1016/s0886-3350(13)80025-9
[27] Luo Y, Li H, Chen W, et al. A prospective randomized clinical trial of active-fluidics versus gravity-fluidics system in phacoemulsification for age-related cataract (AGSPC). Ann Med. 2022;54(1):1977-1987. doi:10.1080/07853890.2022.2098375
[28] Su YC, Lee YY, Su YC. Active-fluidics versus gravity-fluidics in lens extraction: a systematic review and meta-analysis of randomized controlled trials. Eur J Ophthalmol. 2023;33(1):247-256. doi:10.1177/11206721221107512.Kokubun T et al. Verification for the usefulness of normal tension cataract surgery.” Presented at: the 126th annual meeting of the Japanese Ophthalmological Society; April 14-17, 2022; Osaka, Japan.
[29] Kokubun T et al. Verification for the usefulness of normal tension cataract surgery.” Presented at: the 126th annual meeting of the Japanese Ophthalmological Society; April 14-17, 2022; Osaka, Japan.
[30] Rauen MP, Joiner H, Kohler RA, O’Connor S. Phacoemulsification using an active fluidics system at physiologic vs high intraocular pressure: impact on anterior and posterior segment physiology. J Cataract Refract Surg. 2024;50(8):822-827. doi:10.1097/j.jcrs.0000000000001457
[31] O’Brien PD, Fulcher T, Wallace D, Power W. Patient pain during different stages of phacoemulsification using topical anesthesia. J Cataract Refract Surg. 2001;27(6):880-883. doi:10.1016/s0886-3350(00)00757-4
[32] Cionni RJ, Barros MG, Osher RH. Management of lens-iris diaphragm retropulsion syndrome during phacoemulsification. J Cataract Refract Surg. 2004;30(5):953-956. doi:10.1016/j.jcrs.2004.01.030
[33] Hou CH, Lee JS, Chen KJ, Lin KK. The sources of pain during phacoemulsification using topical anesthesia. Eye (Lond). 2012;26(5):749-750. doi:10.1038/eye.2012.29
[34] Collaborative Normal-Tension Glaucoma Study Group. The effectiveness of intraocular pressure reduction in the treatment of normal-tension glaucoma. Am J Ophthalmol. 1998;126(4):498-505. doi:10.1016/s0002-9394(98)00272-4
[35] The AGIS Investigators. The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration. Am J Ophthalmol. 2000;130(4):429-440. doi:10.1016/s0002-9394(00)00538-9
