The modified ExPRESS® technique shows promise in treating open-angle glaucoma secondary to hereditary transthyretin amyloidosis (hATTR), according to a study published in Clinical Ophthalmology.

The ExPRESS Glaucoma Filtration Device is a modified trabeculectomy option that it establishes a connection to the anterior chamber through the device itself instead of a direct fistula. ExPRESS implantation has been found to be both safe and effective in treating open-angle glaucoma and is a technically easier procedure than trabeculectomy. 

The authors of the study sought to investigate the outcomes of patients with glaucoma secondary to hATTR who had undergone an ExPRESS modified procedure in their department. They included patients with a diagnosis of hATTR confirmed by genetic testing who demonstrated uncontrolled intraocular pressure despite maximum topical treatment. Participants underwent surgical operations performed by 4 skilled glaucoma consultant surgeons. 

The main endpoints of the study were the intraocular pressures at baseline, day 1, week 1, and every few months up to a year, extending to the last follow-up. The treatment was considered a success if intraocular pressure decreased by 30% or more from baseline and if the intraocular pressure fell to 18 mmHg or below. If no further medications were required, the surgery was said to be a complete success. 

Read more about hATTR treatment 

Thirty-two eyes were included in this study. The research team determined that qualified success was achieved in 6 eyes, while complete success was achieved in 22 eyes. Surgical failure, meaning the need for further glaucoma surgeries, was observed in 4 eyes. 

“In conclusion, the ExPRESS modified technique seems to be effective, particularly when a lower intraocular pressure is required,” the authors of the study wrote. “Also, with this novel technique, a lower number of antiglaucoma medications was necessary.”

In hATTR, the extracellular deposition of amyloid fibrils causes dysfunction in various organs, including the peripheral nerves, ocular tissues, and heart. Ocular tissue damage may include optic neuropathy, retinal vascular changes, and anterior capsule opacity of the lens. 

Gene therapy has emerged as a viable treatment option that improves quality of life and extends survival. However, it does not decrease ocular transthyretin production. Hence, patients remain vulnerable to glaucoma, which requires immediate surgical intervention if the intraocular pressure rises rapidly. 


Vieira R, Marta A, Ferreira A, et al. Modified technique of Ex-PRESS® filtration device combined with a scleral pocket for hereditary transthyretin amyloidosis (hATTR) secondary open-angle glaucomaClin Ophthalmol. 2023;17:403-411. doi:10.2147/OPTH.S394360