Rate of Corneal Grafting Post-Glaucoma Drainage Device Use in Pediatric and Adult Patients

Effect of guided Ahmed glaucoma valve implantation on corneal endothelial cells: A 2-year comparative study

PURPOSE

To compare the effects of guided and non-guided Ahmed glaucoma valve (AGV) implantation on the corneal endothelium.

METHODS

Medical records of patients who underwent AGV implantation in the anterior chamber (AC) were reviewed retrospectively. The eyes were divided into two groups depending on the use of a guidance technique with spatula and a 4-0 nylon intraluminal stent. Specular microscopy was performed to measure corneal endothelial cell density (ECD) loss after surgery, and the rate of ECD change was calculated. Tube parameters were measured using anterior segment optical coherence tomography (AS-OCT).

RESULTS

The ECD loss during 2 years of follow-up was significantly lower in the guided AGV implantation (gAGV) group than in the non-guided implantation (ngAGV) group, and the rate of ECD change was -0.62 ± 1.23 and -1.42 ± 1.57%/month in the gAGV and ngAGV groups, respectively (p = 0.003). The mean tube-cornea distance (TCD) and mean tube-cornea angle (TCA) were significantly greater in the gAGV group than in the ngAGV group. The frequency of tube repositioning within 2 years after surgery was 0% in the gAGV group and 12.66% in the ngAGV group (p = 0.005).

CONCLUSIONS

The use of a guidance technique can reduce corneal endothelial loss during the first 2 years after AGV implantation in the AC. The tube was positioned at a more distant and wider angle from the cornea in the eyes of the gAGV group, which may have contributed to the reduced need for tube repositioning to prevent corneal decompensation.

Corneal Edema and Keratoplasty: Risk Factors in Eyes With Previous Glaucoma Drainage Devices

PURPOSE

To assess risk factors contributing to corneal decompensation following glaucoma drainage device (GDD) implantation.

DESIGN

Retrospective case control study.

METHODS

Records of 1610 eyes that underwent GDD implantation between June 1, 2009, and April 1, 2020, at the Johns Hopkins Wilmer Eye Institute were reviewed. Seventy-nine eyes (5%) developed corneal decompensation, of which 46 underwent keratoplasty. These 79 cases were matched with 220 controls. Cox proportional hazard models with robust standard error estimates to account for clustering at the matched-pair level were used to assess risk factors for corneal decompensation. Kaplan-Meier survival analysis analyzed time to corneal decompensation.

RESULTS

The mean (SD) age of cases and controls was 68 (12.3) and 60.5 (15.9) years, respectively. The mean time from GDD implantation to corneal decompensation was 32 months, and the cumulative probability of developing decompensation at 3, 6, and 9 years was 4.7%, 9.2%, and 14.8%, respectively. Final visual outcomes in cases were worse, 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). In the multivariable model, significant risk factors for corneal decompensation were increased age (adjusted hazard ratio [AHR] 1.39, 95% CI 1.18, 1.63; P ≤ .001), history of Fuchs dystrophy or iridocorneal endothelial syndrome (AHR 9.18, 95% CI 5.35, 15.74; P ≤ .001), and postoperative complications such as hypotony (AHR 3.25, 95% CI 1.85, 5.72; P ≤ .001) and tube-cornea touch (AHR 6.37, 95% CI 3.77, 10.75; P ≤ .001).

CONCLUSIONS

The risk of postoperative corneal decompensation is persistent over time. Patients receiving GDDs, particularly those with advanced age, preexisting corneal pathology, and postoperative complications, should be counseled regarding their increased risk for corneal decompensation.