Long-Term Endothelial Loss May Be Greater After Glaucoma Drainage Device Implant

Patients who receive minimally invasive glaucoma surgery implants (MIGS) may need to be followed for longer than 3 years on account of the potential for endothelial cell density (ECD), according to a meta-analysis presented at the American Academy of Ophthalmology (AAO) 2022 annual meeting in Chicago, held September 30 to October 3. Researchers who presented the study compared corneal ECD loss after incisional standalone glaucoma surgeries with procedures that combined phacoemulsification and a filtration device implantation. 

In June 2020, the researchers began the comprehensive search of randomized controlled trials, prospective nonrandomized and observational studies published in English since January 1, 2000 in Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, Embase, MEDLINE, the International Prospective Register of Systematic Reviews (PROSPERO), and reference lists of published papers. Investigators included 39 of the most applicable studies. 

The investigators compared study outcomes for corneal decompensation data, as well as ECD cell loss at 12 months postoperatively. In quantitative analysis of pooled data, average density loss following trabeculectomy proved to be 33 (-38 to 105) cells/mm² (95% CI, P =.36). The investigation notes this computation reflects moderate certainty.

Following Schlemm canal procedures that did not involve implants, mean ECD loss was 64 cells/mm², compared with loss after Schlemm canal with implants at 338 cells/mm² (both calculations with low certainty). Eyes that underwent aqueous shunt surgery showed ECD reduction by 5.75% after 12 months, and 8.11% at 24 months, compared with fellow eyes, again reflecting low certainty evidence. 

Suprachoroidal minimally invasive glaucoma surgery (MIGS) 12-month postoperative ECD loss was 282 cells/mm², but this measure represented very low certainty.

“There is low-certainty evidence to suggest that glaucoma surgery involving long-term implants has a greater extent of ECD loss than glaucoma filtration surgeries without the use of implants. This supports long-term follow-up (>36 months) of ECD loss after glaucoma surgery,” according to the analysis.