Outcomes of Descemet Stripping Endothelial Keratoplasty in Eyes With Pars Plana Versus Anterior Chamber Glaucoma Drainage Devices

Abstract

Purpose: To compare visual outcomes and complications of Descemet stripping endothelial keratoplasty (DSEK) in eyes with anterior chamber (AC) versus pars plana (PP) glaucoma drainage devices (GDDs). Methods: A retrospective chart review was conducted of 85 eyes that underwent DSEK and had previous or concurrent AC (37 eyes) or PP (48 eyes) GDD implantation. Outcome measures examined included visual acuity, donor dislocation rate, intraocular pressure, and secondary graft failure (SGF). Results: The mean logarithm of the minimum angle of resolution vision improved from 1.50 (SD = 0.64) to 0.88 (SD = 0.71) in the AC group and from 1.37 (SD = 0.59) to 1.20 (SD = 0.76) in the PP group, with no significant group difference. Intraocular pressure did not differ between the groups preoperatively but was higher in the AC group compared with the PP group postoperatively [mean (SD) 14.5 (6.28) versus 11.5 (5.54) mm Hg, P = 0.03]. Graft dislocation occurred in 35.1% and 29.2% of eyes in the AC and PP groups, respectively. SGF occurred in 18.9% and 41.7% with median time 17.1 (interquartile range [IQR] 4.6–32.1) and 27.9 (IQR 15.1–34.7) months to development in the AC and PP groups, respectively. Multivariable logistic and Cox proportional hazards regression models found no statistically significant factors (tube location, age, sex, concurrent tube revision, new tube insertion) associated with either donor dislocation or SGF. Conclusions: There was no reduction in donor dislocation or SGF in eyes with PP compared with AC GDD, despite the decreased proximity of the shunt from the endothelial graft. Overall, GDD has a significantly adverse effect on long-term graft survival and close follow-up is warranted.

Glaucoma in Patients With Endothelial Keratoplasty

“…A different study comparing 37 DSEK eyes with prior anterior chamber glaucoma tube shunts versus 48 DSEK eyes with prior pars plana tube shunts did not find a significant difference in secondary graft failure rate after controlling for differences in follow-up time. 79 Other studies, albeit not specific to EK eyes, have shown that positioning of a tube closer to the cornea results in more endothelial cell loss. 80,81 For example, Zhang et al 82 have shown that a drainage tube in the anterior chamber was associated with faster central ECD loss compared with a drainage tube in the sulcus in pseudophakic patients.…”

“…10 Tubes in the posterior chamber are less likely to cause damage to the cornea and to induce the formation of peripheral anterior synechiae, although evidence for this is lacking in EK recipients. 29,79 Furthermore, the risk of tube erosion may be reduced in EK patients compared with PK patients because of decreased dosing of topical cortical steroids. 9,117 Currently, no studies address the efficacy or safety of valved tube shunts in comparison with nonvalved tube shunts in keratoplasty patients.…”

Xen Gel Stent as a minimally invasive option for intraocular pressure control after DSAEK: A case study

“…11,12 In order to reduce the endothelial damage, surgeons have increased the tube-corneal distance by performing pars plana GDD implants; this new surgical technique, however, has not shown the desired enhanced graft survival. 13 Considering the previously reported scientific papers; the inflammation caused by intraoperative manipulation in case of trabeculectomy; the complications of the GDD implantations with particular focus on the high rate of graft failure; the risk of graft rejection due to inflammation and ocular surface disruption in case of cyclodestructive procedures; we decided to implant a Xen45 Gel Stent, after DSAEK, as a minimally invasive glaucoma surgery (MIGS). Xen implantation is a brief, ab interno surgical procedure that has shown to cause less chronic inflammation, and therefore fibrinogenesis, than trabeculectomy or medical therapy.…”