This article was originally published in a sponsored newsletter.
Ocular surface disease (OSD) is a significant concern following both traditional surgery and minimally invasive glaucoma surgery (MIGS) because it has the potential to affect surgical outcomes and patients’ quality of life. Understanding this issue is crucial for optimal patient management.
Traditional filtration surgery, particularly trabeculectomy, often leads to ocular surface complications due to several factors. The creation of a conjunctival bleb disrupts the normal tear film distribution and can cause localized dry spots. The intraoperative use of antifibrotics such as mitomycin C and 5-fluorouracil can result in goblet cell loss and conjunctival epithelial damage, potentially leading to tear film instability. It is important to remember that these patients likely had pre-existing OSD associated with topical anti-glaucoma polypharmacy, so the additive effect of surgically induced OSD can be significant.
Other bleb-related ocular surface challenges include dellen formation near elevated blebs, tear film instability over irregular bleb surfaces, exposed sutures causing mechanical irritation, and chronic inflammation that affects meibomian gland function. The use of topical preservatives, particularly benzalkonium chloride (BAK) in postoperative medications, can exacerbate OSD by causing epithelial cell damage, inflammatory cell infiltration, reduced goblet cell density and increased tear film evaporation.
Fortunately, MIGS procedures generally have a favorable ocular surface profile compared to traditional surgery. This advantage stems from smaller incisions, complete absence of conjunctival manipulation, reduced or eliminated need for antifibrotics, fewer postoperative medication requirements and preservation of conjunctival tissue for future interventions. However, MIGS procedures are not entirely free from ocular surface complications.
Procedures such as the Xen gel, which create subconjunctival filtration, can still lead to bleb-related OSD–albeit usually less severe than OSD following traditional trabeculectomy–likely because micro-invasive bleb surgery creates a much more posteriorly biased bleb compared to trabeculectomy. The lack of conjunctival incisions and subsequent sutures can also favorably impact the ocular surface.
Prevention and management of post-surgical OSD should include preoperative optimization of the ocular surface, careful surgical technique to minimize tissue trauma, use of preservative-free medications when possible and early recognition and treatment of OSD symptoms. Surgeons should also “trust their MIGS” and be comfortable reducing topical anti-glaucoma agents, instead taking advantage of the opportunity surgery provides to safely discontinue medications based on IOP and disease severity. Reintroduction of sustained drug delivery and laser trabeculoplasty can be applied as needed to further reduce topical medication dependence.
Chronic OSD can affect surgical outcomes through increased risk of bleb fibrosis, compromised IOP control, reduced patient compliance with medications and decreased quality of life. The impact of OSD on surgical success highlights the importance of regular ocular surface health monitoring, early intervention for OSD symptoms, patient education about proper eye care and consideration of OSD risk in surgical planning. The choice between traditional surgery and MIGS should consider each patient’s pre-existing ocular surface status and risk factors for postoperative OSD. This individualized approach helps optimize surgical outcomes and patient satisfaction.
