A glaucoma drainage device may be more effective than trabeculectomy in lowering IOP after keratoplasty, but is more likely to result in graft failure

The Science behind the Tip

A well-controlled intraocular pressure (IOP) after penetrating keratoplasty (PK) is essential for graft survival and to prevent endothelial cell loss (1). However, raised IOP is a common consequence of this surgery, particularly in patients with pre-existing peripheral anterior synechiae or a preoperative diagnosis of glaucoma (1,2). Obtaining accurate IOP measurements after PK can be difficult and may result in a delay in recognising this complication (1).

A recent retrospective case series comparing the outcomes after trabeculectomy and mitomycin C with glaucoma drainage device (GDD) implantation after PK, concluded that the IOP was significantly more likely to be lower than 22mmHg in the GDD group at the last visit (86.7% vs 64.3%, p = 0.04). Although the IOP was more likely to be controlled at 3 years after GDD implantation, the probability of graft failure was higher (52.6% vs 67.7%, p = 0.54) (3).

Contributor: PD Marc Toeteberg-Harms MD - University Hospital Zurich

References

1. Kornman HL, Gedde SJ, Glaucoma management after corneal transplantation surgeries. Curr Opin Ophthalmol 2016; 27 (2): 132-9

2. Karadag O, Kugu S, Erdogan G et al. Incidence of and risk factors for increased intraocular pressure after penetrating keratoplasy. Cornea 2010; 29:278-282.

3. Yakin M. Eksioglu U, Yainiz-Akkaya Z et al. Outcomes of trabeculectomy and glaucoma drainage devices for elevated intraocular pressure after penetrating keratoplasy. Cornea 2018 June: 37 (6) 705-711

Tip Reviewer: Roger Hitchings
Tip Editor: John Salmon