Subconjunctival Air Leakage After Descemet's Stripping Automated Endothelial Keratoplasty(DSAEK) in a Post-Trabeculectomy Eye

Graft detachments in endothelial keratoplasty

Graft detachment is the most common complication of endothelial keratoplasty. With the ongoing advancements in the field of endothelial keratoplasty, our understanding of risk factors of graft detachments and its management has been evolving. Various prevention measures have been described in literature including presoaking the donor graft, anterior chamber tamponade, venting incisions, sutures to prevent dislocation of graft. Management of a detached graft involves secondary interventions such as rebubbling, suturing and regrafts. In this review, we discuss graft detachment in different types of endothelial keratoplasty techniques including Descemet stripping endothelial keratoplasty, Descemet stripping automated endothelial keratoplasty and Descemet's membrane endothelial keratoplasty; with emphasis on incidence, risk factors, preventive measures and their management.

Ahmed glaucoma valve implant: surgical technique and complications

Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications.

Elevated Intraocular Pressure after Descemet Stripping Automated Endothelial Keratoplasty in Patients with a Trabeculectomy: A Case Series

We report a case series of three patients with previous trabeculectomies who developed elevated intraocular pressure (IOP) in the immediate postoperative period after routine Descemet stripping automated endothelial keratoplasty (DSAEK). All patients had functioning trabeculectomies preoperatively, and developed elevated IOP between 41 and 69 mm Hg within 24 hours following DSAEK surgery. The IOP was successfully controlled in all patients with topical IOP-lowering medications and oral acetazolamide, with the addition of ocular massage and release of aqueous for two patients. Thereafter, all patients maintained well-controlled IOPs. Patients with trabeculectomies should be followed-up closely immediately after DSAEK to monitor for raised IOP. The mechanism for this pressure rise is uncertain, but may involve air in the trabeculectomy sclerostomy or bleb resulting in blockage of aqueous flow.

How to cite this article: Sheales MPH, Chan E, Ang GS, Kong YXG. Elevated Intraocular Pressure after Descemet Stripping Automated Endothelial Keratoplasty in Patients with a Trabeculectomy: A Case Series. J Curr Glaucoma Pract 2015;9(3):100-103.

Corneal transplantation and glaucoma

Glaucoma is the leading cause of irreversible vision loss post-keratoplasty and an important cause of graft failure. With newer techniques, such as lamellar, endothelial, and laser-assisted keratoplasty as well as keratoprosthesis gaining popularity, clinicians will need to consider the incidence, risks, evaluation, and management of glaucoma for each type of keratoplasty when determining which type of transplant may be most appropriate. A comprehensive literature search of glaucoma in the setting of corneal transplantation was performed and serves as the basis for this review. Preexisting glaucoma and aphakia are notable risk factors. Patients that are candidates for deep anterior lamellar keratoplasty may benefit from reduced rates of post-keratoplasty glaucoma. Although glaucoma also complicates eyes with Descemet stripping endothelial keratoplasty, the severity is less and the intraocular pressure is more easily controlled when compared to penetrating keratoplasty. Endothelial keratoplasty creates unique perioperative issues mostly related to management of anterior chamber air bubbles.

Combined deep sclerectomy and descemet stripping automated endothelial keratoplasty

PURPOSE

The aim of this study was to evaluate a novel surgical combination of Descemet stripping automated endothelial keratoplasty (DSAEK) and deep sclerectomy (DS) for the management of concomitant corneal endothelial decompensation and uncontrolled glaucoma.

METHODS

This retrospective case series noncomparative study included 9 eyes of 6 consecutive patients with coexistence of corneal edema resulting from Fuchs dystrophy or pseudoexfoliation keratopathy and medically uncompensated glaucoma; these patients underwent combined DSAEK and DS with mitomycin C and an absorbable collagen implant. Corneal graft clarity, endothelial cell density, visual acuity, intraocular pressure (IOP), and identification of complications were assessed over a 2-year follow-up.

RESULTS

All eyes obtained graft clarity throughout the follow-up, with a final average endothelial cell decrease of -36% from baseline, and showed improved vision and good IOP control without hypotensive therapy. Measured at 3 and 24 months postoperation, the mean visual acuity improvement was 154% and 372% and IOP decrease was 51.1% and 46.4%, respectively. Two anterior segment complications occurred in 2 (22%) patients' eyes. This consisted of a graft dislocation and a modest IOP elevation, treated successfully.

CONCLUSIONS

Combined DSAEK and DS was longitudinally associated with good corneal graft survival and IOP control, with few complications. These findings suggest that this surgical approach is a viable option for patients with coexisting glaucoma and corneal endothelial dysfunction. Our study should stimulate a multicenter, randomized, controlled trial of our technique.

New continuous air pumping technique to improve clinical outcomes of descemet-stripping automated endothelial keratoplasty in asian patients with previous ahmed glaucoma valve implantation

BACKGROUND

To evaluate the outcomes of Descemet-stripping automated endothelial keratoplasty (DSAEK) with the use of continuous air pumping technique in Asian eyes with previous Ahmed glaucoma valve implantation.

METHODS

The DSAEK procedure was modified in that complete air retention of the anterior chamber was maintained for 10 min using continuous air pumping at 30 mm Hg. The primary outcome measurement was graft survival, and postoperative clinical features including, rate of graft detachment, endothelial cell count, intraocular pressure (IOP), surgical time and cup/disc ratio were also recorded.

RESULTS

A total of 13 eyes of 13 patients which underwent modified DSAEK and 6 eyes of 6 patients which underwent conventional DSAEK were included. There was a significant difference in graft survival curves between two groups (P = 0.029); the 1-year graft survival rates were estimated as 100% and 66.7% for patients with modified DSAEK and those with traditional DSAEK, respectively. The rate of graft detachment were 0% and 33.3% for the modified DSAEK and conventional DSAEK groups, respectively (P = 0.088). The significantly lowered surgical time for air tamponade was noted in the modified DSAEK group compared to that in the conventional DSAEK group [median (IQR): 10.0 (10.0, 10.0) min vs. 24.5 (22.0, 27.0) min; P<0.001] Postoperatively, patients in the modified DSAEK group had significantly lower IOP as compared to the conventional DSAEK group [12.0 (11.0, 15.0) mm Hg vs. 16.0 (15.0, 18.0) mm Hg; P = 0.047]. Modified DSAEK patients had higher endothelial cell counts as compared to conventional DSAEK patients [2148.0 (1964.0, 2218.0) vs. 1529.0 (713.0, 2014.0)], but the difference did not reach statistical significance (P = 0.072).

CONCLUSIONS

New continuous air pumping technique in DSAEK can be performed safely and effectively in patients with prior GDDs placement who have corneal failure.

Increased Rates of Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) Graft Failure and Dislocation in Glaucomatous Eyes with Aqueous Shunts

PURPOSE

To investigate the rates of Descemet's stripping automated endothelial keratoplasty (DSAEK) graft dislocation and failure in glaucomatous eyes, including eyes with history of trabeculectomy and/or aqueous shunts.

METHODS

A retrospective, case-control study on a total of 424 consecutive eyes undergoing DSAEK at an academic setting compared 96 glaucomatous eyes to a control group of 328 eyes. Pre- and post DSAEK procedure data was aggregated for up to 2 years (mean follow-up, 6.5±6.9 months) including rates of graft dislocation and failure.

RESULTS

Out of 96 glaucomatous eyes, 20 had undergone trabeculectomy, 27 had received one or more aqueous shunts, 12 had undergone both procedures and 37 were on medical therapy. Complete DSAEK graft dislocation and failure occurred in 2.7% and 3% of non-glaucomatous patients, respectively. Eyes with history of aqueous shunt surgery experienced graft dislocation and failure rates of 26.0% (OR=4.6, 95% CI 1.5-13.7, p=0.0067) and 26.0% (OR=10.3, 95% CI 3.8-27.1, p<0.0001), respectively. In contrast, glaucomatous eyes only on medical therapy (p=0.13) or with history of trabeculectomy (p>0.40) had no significant increase in graft dislocation or failure rates.

CONCLUSION

Eyes with medically controlled glaucoma or prior trabeculectomy demonstrated comparable rates of graft dislocation and failure as compared to controls. Aqueous shunt surgery was associated with increased rates of graft dislocation and failure after DSAEK.

Histopathological findings of failed grafts following Descemet's stripping automated endothelial keratoplasty (DSAEK)

PURPOSE

To study the histopathological findings of the early cases of failed DSAEK grafts and to analyze the causes of graft failure.

METHODS

Retrospective study of 13 failed DSAEK grafts (four grafts submitted alone with no host cornea) of 12 patients. The histopathologic features are correlated with the clinical and operative findings.

RESULTS

Significant attenuation of the endothelial cells found in 10/13 cases (77%), retained recipient Descemet's membrane in 7/13 (54%), variability of graft thickness in 5/13 (38%) and two of these had stromal irregularity. Retrocorneal fibrous membrane along the donor's Descemet's membrane was found in 4/13 (31%) resulting in endothelial detachment in one case. Eight of the nine host cornea-graft specimens were found to have: total graft-cornea detachment (in one), subtotal in four and partial (⩽50% of graft length) in three. The detached flaps showed infection at the interface of the graft-host cornea in two, epithelial ingrowth and fibrous proliferation along the anterior stromal surface of the graft (one case each). An additional histopathological finding was secondary amyloid deposition within the host stroma (in one).

CONCLUSION

Irregular or thick graft, graft-host interface fibrous/epithelial ingrowth, and infection all predispose to DSAEK failures related to graft detachment. Endothelial cells attenuation and retrocorneal fibrous membrane are major causes for primary graft failure.