Cost-Effectiveness of Selective Laser Trabeculoplasty (SLT) versus Argon Laser Trabeculoplasty (ALT) in Uncontrolled Open Angle Glaucoma Patients having at least One Full Previous SLT: An Economic Evaluation Alongside an Ongoing Randomized Controlled Clinical Trial

Background and objective: ALT and SLT are both safe and effective for glaucoma treatment. We performed a cost-effectiveness analysis (CEA) of SLT versus ALT for a six-month follow-up period in uncontrolled open angle glaucoma patients having at least one full previous SLT from an ongoing RCT. Methods: Trial based treatment costing and IOP reduction at 6-month follow-up from baseline for both intervention arms were calculated. A decision tree model was developed considering possible clinical pathways of patients undergoing repeat laser trabeculoplasty. CEA among ALT and SLT was done, and ICERs were calculated from both societal and ministry perspective. One way sensitivity analysis was done for cost and effectiveness parameters. Results: From Societal perspective, expected cost/effectiveness for ALT and SLT was $458/0.143 mmHg vs $448/0.123 mmHg respectively and from ministry perspective, $467/0.154 mmHg vs $446/0.122 mmHg, respectively. To switch from SLT to ALT, it would cost $ 356.49 for each extra unit IOP reduction from societal perspective and from ministry perspective, the same would cost $ 649.71. This ICERs were much higher in comparison to ICERS of other IOP lowering medications in similar situations. Conclusion: Neither ALT nor SLT strategies were clearly dominated by any other. ALT is slightly more effective and slightly costly over SLT. Sensitivity analysis with effectiveness variables showed dominance of SLT over ALT for some instances. SLT has the theoretical plausibility of repeatability and is also easier to perform than ALT. All these factors should be considered when opting between ALT and SLT strategies