Significant risk factors associated with corneal decompensation following glaucoma drainage device (GDD) implantation include older age, preexisting corneal pathology, and postoperative complications, according to a study published in the American Journal of Ophthalmology. The analysis also reveals that the risk of corneal decompensation persists for years after surgery.       

Investigators retrospectively reviewed medical records of 1610 eyes that underwent GDD implantation between June 1, 2009 and April 1, 2020. They determined that 79 eyes (5%) developed corneal decompensation, of which 46 underwent keratoplasty. These 79 cases were matched with 220 control eyes of 220 patients. The researchers used univariate and multivariable Cox proportional models to evaluate risk factors for corneal decompensation. 

The mean standard deviation (SD) age of cases and controls was 68±12.3 years and 60.5±15.9 years, respectively. The mean time from GDD implantation to onset of corneal decompensation was 32 months (range: 3 months to 98 months). The cumulative probability of experiencing decompensation at 3, 6, and 9 years was 4.7%, 9.2%, and 14.8%, respectively. 


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In the univariate model, higher risk of corneal decompensation was associated with older age at the time of GDD implantation (hazard ratio (HR), 1.44; 95% CI, 1.24 to 1.67), postoperative hypotony (HR, 4.46; 95% CI, 2.74 to 7.28), a history of Fuchs dystrophy or iridocorneal endothelial (ICE) syndrome (HR, 7.29; 95% CI, 4.23 to 12.6), and a higher number of previous glaucoma surgeries (HR, 1.39; 95% CI, 1.10 to 1.74).

In the multivariable model, higher risk of corneal decompensation was associated with older age, (adjusted hazard ratio (AHR), 1.39; 95% CI, 1.18 to 1.63), postoperative hypotony (AHR, 3.25; 95% CI, 1.85 to 5.72), tube-cornea touch (AHR, 6.37; 95% CI, 3.77 to 10.75), and a history of fuchs dystrophy or ICE syndrome (AHR, 9.18; 95% CI, 5.35 to 15.74).

At the final visit, patients who developed corneal decompensation had poorer visual outcomes, with a final mean SD visual acuity (LogMAR) of 1.96±1.25 relative to a mean SD visual acuity of 1.11±1.36 in controls (P <.001).

“Our data in particular showed a persistent corneal edema rate that was nearly double that of the keratoplasty rate, highlighting the importance of using persistent corneal edema as a marker for postoperative corneal decompensation rather than keratoplasty alone,” the study explains. “This is especially pertinent in eyes with severe glaucomatous damage, where the indications for a keratoplasty procedure are narrowed due to poor expected visual outcomes.”

Limitations of the study include the retrospective nature and the possibility of inaccurate intraocular pressure (IOP) measurements.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.  

Reference

Beatson B, Wang J, Boland MV, et al. Corneal edema and keratoplasty: risk factors in eyes with previous glaucoma drainage devices. Am J Ophthalmol. Published online January 4, 2022. doi:10.1016/j.ajo.2021.12.017