Dendumrongsup Wichapol
General Practice, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand.
Cureus. 2024 Feb 13;16(2):e54116. doi: 10.7759/cureus.54116. eCollection 2024 Feb.
Selective laser trabeculoplasty (SLT) emerges as a first-line treatment for newly diagnosed open-angle glaucoma and ocular hypertension. However, the interindividual response to SLT considerably varied. Large-scale clinical investigations concerning predictive factors for SLT effectiveness are limited. This study aimed to identify baseline predictors of the percentage intraocular pressure (IOP)-lowering effectiveness of SLT using an alternative mathematical approach.
Mathematical equations of IOP under the steady state of aqueous humour flow were formulated. The conclusive equation integrates physiological variables, including trabecular outflow facility, uveoscleral outflow fraction, plasma protein concentration, albumin/globulin ratio, mean arterial pressure, episcleral venous pressure, and plasma osmolarity. The equation was employed to estimate the percentage of IOP reduction following SLT and subsequently subjected to global sensitivity analysis to determine significant predictors of the IOP-lowering effect of SLT using the Monte Carlo simulation of 8,192 samples.
In the current model, a 50% improvement in the trabecular outflow facility impacted by SLT is associated with a mean percentage IOP reduction of 16.6%. Lower baseline trabecular outflow facilities were the strongest predictors, showing a correlation with greater effectiveness of SLT in terms of percentage of IOP reduction. The second most influential factor includes baseline uveoscleral outflow fraction, followed by baseline episcleral venous pressure. Specifically, lower baseline uveoscleral outflow fraction and episcleral venous pressure were found to be correlated with increased effectiveness of SLT. Baseline levels of plasma protein concentration, albumin/globulin ratio, mean arterial pressure, and plasma osmolarity have minimal impact on SLT success or failure.
This study identifies baseline trabecular outflow facilities as the strongest predictor of SLT effectiveness. The results suggested that pre-SLT medical treatment that augments uveoscleral outflow and/or trabecular outflow facilities could compromise the effectiveness of subsequent SLT in terms of percentage IOP reduction compared to those who never received pre-SLT medication.
选择性激光小梁成形术（SLT）已成为新诊断开角型青光眼和高眼压症的一线治疗方法。然而，个体对SLT的反应差异很大。关于SLT疗效预测因素的大规模临床研究有限。本研究旨在使用一种替代数学方法确定SLT降低眼压（IOP）有效性百分比的基线预测因素。
建立了房水流动稳态下IOP的数学方程。最终方程整合了生理变量，包括小梁网流出易度、葡萄膜巩膜流出分数、血浆蛋白浓度、白蛋白/球蛋白比值、平均动脉压、巩膜静脉压和血浆渗透压。该方程用于估计SLT后IOP降低的百分比，随后进行全局敏感性分析，使用8192个样本的蒙特卡罗模拟确定SLT降低IOP效果的显著预测因素。
在当前模型中，SLT影响下小梁网流出易度提高50%与IOP平均降低百分比16.6%相关。较低的基线小梁网流出易度是最强的预测因素，就IOP降低百分比而言，显示与SLT的更高疗效相关。第二大影响因素包括基线葡萄膜巩膜流出分数，其次是基线巩膜静脉压。具体而言，较低的基线葡萄膜巩膜流出分数和巩膜静脉压与SLT疗效增加相关。血浆蛋白浓度、白蛋白/球蛋白比值、平均动脉压和血浆渗透压的基线水平对SLT的成败影响最小。
本研究确定基线小梁网流出易度是SLT疗效的最强预测因素。结果表明，与从未接受SLT前药物治疗的患者相比，增加葡萄膜巩膜流出和/或小梁网流出易度的SLT前药物治疗可能会在IOP降低百分比方面损害后续SLT的疗效。
