Two new studies report the potential benefits of trabeculectomy for the ocular surface, including the findings that a combination of surgery and halting glaucoma medication was beneficial to the ocular surface, in addition to the procedure’s reported ability to reduce the level of pro-inflammatory lipid mediator in tears.
The first investigation, published online in Acta Opthalmologica, looked at changes in the ocular surface and tear proteomics after patients who had undergone trabeculectomy discontinued their long-term glaucoma medication regimen.1 The Finnish study included 57 patients who had taken anti-glaucoma eye drops for approximately eight years and had undergone a successful trabeculectomy. Investigators took measurements during the preoperative visit and again at one, three, six and 12 months after surgery. All parameters were compared with the corresponding preoperative levels of each individual eye.1
Conjunctival redness and irritation were significantly reduced during follow-up, while tear production remained unchanged. Additionally, protein profiles of the tear film indicated significant changes in the ocular surface, and lipid transport increased while several pro-inflammatory proteins consistently decreased after surgery, the researchers noted.1
The second study, published in The Ocular Surface, focused on the change in six lipid mediators, all of which were reduced post-trabeculectomy.2 The investigation included patients who underwent trabeculectomy and had tear collection using Schirmer’s strips pre-op and at six months, 12 months and three years post-op. The study analyzed lipid mediators using lab techniques to separate out the constituents of tears.2
A total of 14 patients who experienced an increase in the six lipid mediator levels required postoperative needling at one year compared with non-needled patients, and changes in the lipid mediators appeared to be functionally relevant based on the metabolic pathways.2 Also, the investigators found an association between increased levels of one prostaglandin in particular (known as 2,3-dinor-8-isoPGF2α) at baseline and six months with inferior corneal staining at the six-month follow-up.2
“Patients who required needling of the bleb to maintain surgical success may have a chronic underlying inflammatory process associated with fibrosis,” the researchers wrote in their paper.2
1. Vaajanen A, Nättinen J, Aapola U, et al. Acta Opthalmologica. The effect of successful trabeculectomy on the ocular surface and tear proteomics—a prospective cohort study with 1-year follow-up. Acta Opthalmologica. July 9, 2020. [Epub ahead of print].
2. Ambaw YA, Wong T, Chong R, et al. Change of tear lipid mediators in a post-trabeculectomy cohort. The Ocular Surface. July 2, 2020. [Epub, ahead of print].