Glaucoma Filtration Surgery Failure Risk Factors Identified, Outcome Improvement Measures Proposed

Doctor dripping eye drops on eyes of a senior patient
Female doctor dripping eye drops on eyes of a senior patient during a treatment at the ophthalmological office
A majority of glaucoma specialists believe that appropriate ocular surface management is beneficial for patients undergoing glaucoma filtration surgery, but less than half feel it is essential.

Prior to glaucoma filtration surgery (FS), the condition of the ocular surface must be managed appropriately to increase the likelihood of satisfactory patient outcomes, according to a review published in Acta Ophthalmologica. 

Researchers sought to provide risk factors affecting FS outcomes and establish evidence-based guidelines for pre-operatively treating the ocular surface. They found that risk factors for trabeculectomy failure include young age, Black race, diabetes, high intraocular pressure (IOP), severe glaucoma, and concomitant ocular diseases.

They also identified glaucoma therapy-related ocular surface disease (GTOSD) as a major risk factor for FS failure citing that “long-term medical therapy is harmful to the entire ocular surface, especially the conjunctiva.”

Although patients with uncontrolled glaucoma frequently present for FS in less than desirable conditions, investigators say ocular surface risk factors can potentially be modified. Researchers recommend a few methods of mitigating GTOSD prior to surgery. These include switching from preserved to unpreserved formulations and restricting the amount of preoperative medications for a sufficient period of time before surgery.  

Other methods of preparing the ocular surface for FS involve using low-potency steroids to reduce inflammation, administering artificial tears, prescribing systemic tetracyclines, and performing eyelid management with an emphasis on treating meibomian gland dysfunction (MGD). 

The report shows that the vast majority of glaucoma specialists (86%) believe that taking measures to optimize the ocular surface before surgery are beneficial, but less than half (48.4%) consider it necessary. Findings also indicate that most glaucoma surgeons (84%) would modify the routine management of glaucoma when considering ocular surface disease, but only one-third would implement specific strategies to decrease ocular inflammation.

“Because of the strong mutual relationship between the condition of the ocular surface and glaucoma management outcomes, the need to improve the ocular surface before proceeding with FS represents a primary clinical need that should be soon fulfilled,” according to the researchers. They are concerned, however, that “the lack of studies that address this topic and the low level of evidence of the currently existing studies, have not resulted in clear guidelines.”


Agnifili L, Sacchi M, Figus M, et al. Preparing the ocular surface for glaucoma filtration surgery: an unmet clinical need. Acta Ophthalmol. Published online January 28, 2022. doi:10.1111/aos.15098