Tear Interleukin Biomarkers After Glaucoma Treatment (TIGT)

Glaucoma is a chronic progressive optic neuropathy characterized by irreversible visual field loss. Reduction of intraocular pressure (IOP) remains the only evidence-based strategy to slow disease progression. Various treatment modalities, including laser procedures such as micropulse transscleral cyclophotocoagulation (MP-CPC) and continuous-wave cyclophotocoagulation (CPC), as well as incisional antiglaucoma surgeries, are widely used to achieve IOP control.

Inflammation is believed to play a differential role in the biological response to various glaucoma interventions. In the context of CPC and MP-CPC a controlled ("subthreshold") inflammatory response may contribute to structural and functional remodeling of the ciliary body, potentially enhancing the hypotensive effect. Interleukins present in tear fluid represent accessible, non-invasive biomarkers of ocular surface and intraocular inflammatory activity. Changes in their concentrations may reflect procedure-induced tissue response and could potentially serve as predictors of treatment efficacy.

In contrast, following incisional antiglaucoma surgeries, inflammation is more often associated with fibrotic processes, wound healing, and scar formation, which may negatively affect surgical outcomes by limiting aqueous outflow.

However, the dynamics of inflammatory mediators in the tear film following different glaucoma treatments and their relationship with IOP reduction remain insufficiently studied.

This prospective study will include patients with various types of glaucoma scheduled to undergo MP-CPC, CPC, or incisional antiglaucoma surgery. Tear samples will be collected at three time points: preoperatively (baseline), 5-7 days after treatment, and 1 month postoperatively. The concentrations of selected pro-inflammatory (IL-4, IL-6) interleukins will be measured using standardized immunoassay techniques.

Intraocular pressure will be assessed at the same time points using Corvis ST tonometry.

The primary objective of the study is to evaluate the correlation between changes in tear interleukin levels and IOP reduction at early (5-7 days) and short-term (1 month) follow-up.

Secondary objectives include:

Assessment of temporal changes in interleukin profiles after different glaucoma treatments, Comparison of inflammatory responses between MP-CPC, CPC, and surgery groups, Evaluation of the relationship between baseline interleukin levels and the degree of IOP reduction, Identification of interleukin patterns associated with a clinically significant hypotensive response, Safety evaluation, including postoperative complications and ocular surface status.

Correlation and regression analyses will be performed to determine whether baseline interleukin levels and their early postoperative changes can predict the degree and stability of IOP reduction.

The identification of inflammatory biomarkers associated with treatment response may contribute to a better understanding of the role of inflammation in glaucoma management and support the development of personalized therapeutic strategies.