Abstract
Purpose :
Children implanted with glaucoma drainage devices are at life-long risk of corneal decompensation. We evaluated the corneal thickness in different quadrants of pediatric eyes implanted with Ahmed glaucoma valve (AGV), as a surrogate indicator of early possible corneal endothelial compromise.
Methods :
Corneal thickness in 28 eyes of 23 children (age: 0.8 to 12.8 years; mean: 4.8) successfully implanted with superotemporal AGV was compared to thickness in 63 eyes of 40 glaucomatous children of similar age (0.25 to 13.8 years; mean:3.5) without AGV implantation. Thickness was measured in both groups centrally and in the superotemporal, superonasal, inferotemporal and inferonasal quadrants using ultrasound pachymetry. Measurements were taken at 13.5 ± 8 months post valve implantation and without clinical evidence of tube-cornea touch. The study was conducted at Cairo University Hospitals
Results :
The mean corneal thickness was greater in all quadrants in the AGV group, with the central (645 ± 112 vs 590±93 µm; P =0.02) and superotemporal quadrant (695 ± 90 vs 634 ± 88 µm; P <0.01) being statistically significant. The superotemporal quadrant was the thickest of all quadrants (P=<0.01) in the AGV but not in the control group. The difference in thickness between the superotemporal and the inferonasal (the furthest away from the tube end) quadrants was significantly higher in the AGV group (38.9 ± 53.3 vs 0.3 ±35.3 µm; P= <0.01) indicating a localized subclinical corneal edema likely secondary to the tube implant.
Conclusions :
The superotemporal corneal quadrant is significantly the thickest of all quadrants in eyes with a superotemporally implanted Ahmed valve, even in the absence of clinical evidence of tube-cornea touch. Ultrasound pachymetry is a useful tool to monitor for corneal decompensation in children where spectral microscopy is not feasible.
This is a 2021 ARVO Annual Meeting abstract.