There is currently a paucity of evidence for the use of trabeculectomy as the primary treatment for individuals with advanced glaucoma. Recognizing this knowledge gap, King and colleagues implemented a pragmatic and multi-site randomized controlled trial (RCT) comparing patient-reported outcomes, clinical effectiveness, and safety profiles of primary trabeculectomy versus medical treatment in 453 advanced glaucoma patients in the UK. They found that those randomized to Mitomycin-C augmented trabeculectomy (n = 227) had similar quality of life (QoL) and safety profiles, whilst achieving a lower mean intraocular pressure (IOP) reduction of -2.8mmHg as compared to primary medical management (n = 226) at 24 months.
Glaucoma utility index (GUI) as QoL outcomes may not be appropriate as these instruments mostly measure functional disabilities related to deficits in visual acuity and visual fields
While the authors should be congratulated for this excellent study, several limitations must be noted. Firstly, the use of the 25-item Vision Function Questionnaire (NEI-VFQ-25) and the glaucoma utility index (GUI) as QoL outcomes may not be appropriate as these instruments mostly measure functional disabilities related to deficits in visual acuity and visual fields.1,2 As acuity and field measurements were relatively similar at follow-up in both arms, it is hardly surprising that no differences in QoL outcomes were detected. A glaucoma-specific instrument, designed to comprehensively assess the range of glaucoma- related functional, psychological and treatment-related deficits may have been a more appropriate study measure for capturing such outcomes.3 Secondly, the cost differential between the two study arms was not captured by the study investigators. Lastly, the generalizability of these data is a concern, as the majority of participants were white, and over a third of eligible patients declined participation.
The cost differential between the two study arms was not captured by the study investigators
In conclusion, primary trabeculectomy for advanced glaucoma recorded similar QoL and safety profiles to primary medication, while having greater IOP lowering efficacy. These results will need to be confirmed in other large-scale RCTs incorporating appropriate glaucoma-specific patient-reported outcome measures and cost-effectiveness indices before changes to current treatment guidelines can be considered.