Trabeculectomy may slow RNFL progression more than medication alone

In eyes with primary open angle glaucoma (POAG) treated with trabeculectomy surgery, slower rates of change in retinal nerve fiber layer (RNFL) were found compared with treated with medication alone at different levels of mean IOP control, according to a presentation at the 2022 AGS Annual Meeting.

In this prospective cohort study, eyes with POAG that underwent medical treatment without surgical intervention were categorized into a medication group and eyes that underwent trabeculectomy surgery but were not treated with medications or other surgical intervention were categorized into a trabeculectomy group.

Each group was further categorized according to levels of mean IOP control (<15 mmHg, <18 mmHg, and <21 mmHg),

Within each level of mean IOP control, the baseline mean deviation, baseline age, and gender were similar after matching.

• There were 42 eyes that underwent trabeculectomy surgery and 39 eyes that were treated with medication alone that had a mean IOP<15 mmHg. Those in the trabeculectomy group had a significantly less negative RNFL slope compared to eyes in the medication group (slope -0.19 +/- 1.0 vs -0.77 +/- 1.2, P = 0.01).
• There were 48 eyes that underwent trabeculectomy surgery and 41 eyes that were treated with medication alone that had a mean IOP<18 mmHg. Those in the trabeculectomy group had a significantly less negative RNFL slope compared to eyes in the medication group (-0.15 +/- 0.95 vs -0.63 +/- 0.92, P = 0.02).
• There were 56 eyes that underwent trabeculectomy surgery and 50 eyes that were treated with medication alone that had a mean IOP <21 mmHg. Those in the trabeculectomy group had a less negative RNFL slope compared to those in the medication group although the difference did not reach statistical significance (-0.11 +/- 0.89 vs -0.35 +/- 1.0, P = 0.08).

Reference
Thompson A, et al. Comparing the rates of change in retinal nerve fiber layer on optical coherence tomography between trabeculectomy and medically managed eyes with similar intraocular pressure control. Presented at: 2022 AGS Annual Meeting.