Graft failure after penetrating keratoplasty in eyes with Ahmed valves

Clinical Factors Impacting Outcomes From Failed Trabeculectomy Leading to Glaucoma Drainage Device Implantation and Subsequent Penetrating Keratoplasty

PRCIS

We evaluated the factors that impacted time from glaucoma drainage implant (GDI) surgery to penetrating keratoplasty (PK) in eyes with previously clear corneas (ie, GDI-first sequence), and that specifically underwent a trabeculectomy before GDI surgery for intraocular pressure (IOP) control.

PURPOSE

To describe through an event-triggered data collection method the clinical course and the long-term outcomes of 2 procedures that are commonly performed sequentially in complex clinical situations: GDI surgery and PK. The study investigates the clinical factors associated with the progression to PK and determines the GDI success rate and graft survival.

METHODS

A single, tertiary-care center retrospective interventional cases series including patients with a sequential history of trabeculectomy, GDI surgery, and PK from 1999 to 2009. Outcome measures included IOP, visual acuity, graft failure, GDI failure, and time from GDI to PK.

RESULTS

Of the eyes, 56% had primary open angle glaucoma. The time from the last trabeculectomy to GDI was 66.5 ± 66.7 months. Of the eyes, 84% received a Baerveldt GDI. Time from GDI to PK was 36.4 ± 28.4 months. IOP at the time of PK was between 5 mm Hg and 21 mm Hg in 90% of eyes. At the last follow-up, 48% of grafts were clear. At 5 years post-PK, 33% of corneal grafts remained clear, whereas 81% of tubes remained functional.

CONCLUSIONS

Nearly half of the corneal grafts are clear at the last long-term follow-up. Graft failure occurs at a higher rate than tube failure suggesting that IOP control is only one and possibly not the most important factor in graft survival in eyes with prior glaucoma surgery.

Outcomes of XEN Stent in Patients With Glaucoma and Previous Corneal Transplantation

PRCIS

The XEN stent safely and effectively controls intraocular pressure in select patients with history of corneal transplantation.

PURPOSE

Glaucoma is a common complication after corneal transplantation and can be difficult to manage in these patients. This study reports outcomes of XEN stent implantation in eyes with glaucoma in the setting of previous corneal transplantation.

PATIENTS AND METHODS

Noncomparative retrospective case series including eyes with a history of corneal transplantation and subsequent XEN stent implantation by a single glaucoma surgeon in Surrey, British Columbia, between 2017 and 2022. The analysis included patient demographics, pre and postoperative intraocular pressure (IOP), pre and postoperative glaucoma medications, peri and postoperative complications and interventions, and incidence of repeat corneal transplantation and additional glaucoma procedures to control IOP.

RESULTS

Fourteen eyes with previous cornea transplantation underwent XEN stent implantation. Mean age was 70.1 years (range: 47-85 y). Mean follow-up was 18.2 months (range: 1.5-52 mo). The most common glaucoma diagnosis was secondary open angle glaucoma (50.0%). There was a significant reduction in IOP and the number of glaucoma agents at all postoperative time points ( P < 0.05). IOP decreased from 32.7 ± 10.0 mm Hg at baseline to 12.5 ± 4.7 mm Hg at the most recent follow-up. Glaucoma agents decreased from 4.0 ± 0.7 to 0.4 ± 1.0. Two eyes required additional glaucoma surgery to control IOP, with an average time to reoperation of 7 weeks. Two eyes underwent repeat corneal transplantation, with an average time to reoperation of 23.5 months.

CONCLUSIONS

In selected patients with previous corneal transplants and refractory glaucoma, the XEN stent was safely implanted and effectively reduced IOP in the short term.

Comparison of Penetrating Keratoplasty and Descemet Stripping Automated Endothelial Keratoplasty in Eyes with Glaucoma Ahmed Valve implants

Purpose: To compare the clinical outcomes of penetrating keratoplasty (PKP) and Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with Glaucoma Ahmed Valve implants.Methods: The charts of 11 patients who underwent PKP and 11 who underwent DSAEK between February 2016 and June 2018 were retrospectively reviewed; all patients previously underwent Ahmed valve implant surgery. The best corrected visual acuity, intraocular pressure, and endothelial cell count were compared 1, 3, and 6 months after surgery. Graft rejection and graft failure were also evaluated during follow-up. The survival rates were compared using Kaplan–Meier survival analysis.Results: The difference in graft survival rates of the PKP and DSAEK groups was not significant (p = 0.295); however, graft failure occurred earlier in the PKP group (12.9 ± 10.1 vs. 18.8 ± 5.3 months). The postoperative best corrected visual acuity of the PKP group had improved at 1 (p = 0.027) and 3 (p = 0.017) months, while the DSAEK group showed significant improvement at 1, 3, and 6 months (all p = 0.005). Intergroup analysis showed better visual prognosis of the DSAEK group at 1, 3, and 6 months after surgery (p = 0.023, p = 0.007, and p = 0.004, respectively).Conclusions: In our study, the two corneal transplantation methods did not have significantly different graft survival rates; however, graft failure occured later in the DSAEK group and the postoperative visual acuity was better than in the PKP group. Although further study is needed, performing DSAEK in patients with an Ahmed valve implant seems to be a good alternative to PKP.

Corneal Endothelial Cell Loss in Glaucoma and Glaucoma Surgery and the Utility of Management with Descemet Membrane Endothelial Keratoplasty (DMEK)

The corneal endothelium has a crucial role in maintaining a clear and healthy cornea. Corneal endothelial cell loss occurs naturally with age; however, a diagnosis of glaucoma and surgical intervention for glaucoma can exacerbate a decline in cell number and impairment in morphology. In glaucoma, the mechanisms for this are not well understood and this accelerated cell loss can result in corneal decompensation. Given the high prevalence of glaucoma worldwide, this review aims to explore the abnormalities observed in the corneal endothelium in differing glaucoma phenotypes and glaucoma therapies (medical or surgical including with new generation microinvasive glaucoma surgeries). Descemet membrane endothelial keratoplasty (DMEK) is increasingly being used to manage corneal endothelial failure for glaucoma patients and we aim to review the recent literature evaluating the use of this technique in this clinical scenario.

[Descemet membrane endothelial keratoplasty after implantation of glaucoma drainage devices]

Secondary decompensation of corneal endothelium, including transplanted, is a frequent long-term complication of glaucoma drainage surgery. According to literature data, after implantation of a glaucoma drainage device into the anterior chamber, the speed of endothelial cells density (ECD) loss increases significantly.

PURPOSE

To study the possibility of performing modified Descemet membrane endothelial keratoplasty (DMEK) with maximum graft diameter, and to assess its short-term effectiveness in the treatment of bullous keratopathy (BK) in the presence of a glaucoma drainage device in the anterior chamber.

MATERIAL AND METHODS

Modified surgery ³/₄-DMEK was performed in 9 eyes of 7 patients with BK and Ahmed glaucoma drainage using graft of maximum diameter (11±1 mm). Average follow-up time was 15.3±2.5 months (12 to 18 months).

RESULTS

No intraoperative or postoperative complications were observed. Mean ECD after 12 months amounted to 1664±346 cells/mm², which corresponds to ECD reduction of 34±9.6% (24 to 49%) in comparison to preoperative values. Mean best corrected visual acuity 12 months after surgery increased from 0.04±0.03 (0.01 to 0.1) to 0.3±0.2 (0.04 to 0.7). The last follow-up examination revealed all corneas to have preserved transparency and stable pachymetry measurements (from 488 to 548 µm).

CONCLUSION

Performing ³/₄-DMEK with a mega graft for treatment of BK after drainage surgery is technically possible. Absence of Descemet membrane (DM) donor and preservation of DM recipient in the drainage tube plane eliminates its contact with the endothelium. Maximum graft diameter should in the long term help prolong the effectiveness of the surgery.

Ahmed glaucoma valve implantation with the tube placement in the ciliary sulcus: short-term results

PURPOSE

To evaluate the clinical outcomes of pseudophakic/aphakic eyes with uncontrolled glaucoma that underwent Ahmed glaucoma valve implantation with the tube placement in the ciliary sulcus.

METHODS

Medical records of the patients who underwent Ahmed glaucoma valve implantation through the ciliary sulcus, between December 2017 and June 2019, were reviewed retrospectively. Patients' age, gender, glaucoma diagnosis, visual acuity, intraocular pressure levels, and complications were recorded.

RESULTS

Forty-seven eyes of 43 patients with glaucoma were enrolled. The mean age was 54.5 ± 19.9 years (range, 7-88 years) at the time of surgery, and the mean postoperative follow-up period was 7.9 ± 3.4 months (range, 3-16 months). The mean preoperative intraocular pressure level was 35.2 ± 6.8 mmHg (range, 25-55 mmHg), and it was found as 15.6 ± 5.4 mmHg (range, 9-33 mmHg) at the last follow-up visit. Decrease in intraocular pressure level was statistically significant (P < 0.001). At the last follow-up visit, success (postoperative IOP ≥ 6 mmHg and ≤ 21 mmHg with or without antiglaucomatous medications, without further surgery for IOP control, without loss of light perception and without removal of the implant) was achieved in 41 eyes (87.2%). Hyphema was the most common postoperative complication and developed in 11 eyes (23.4%) and resolved spontaneously in all of them within one month.

CONCLUSION

In pseudophakic or aphakic eyes with uncontrolled glaucoma, placement of Ahmed glaucoma valve tube in the ciliary sulcus is a safe and effective procedure. Ciliary sulcus can be considered as a potential space during tube shunt surgery in eyes with high risk of tube-corneal touch or corneal decompensation.

Three-quarter DMEK in eyes with glaucoma draining devices to avoid secondary graft failure

PURPOSE

To present a case series of a modified three-quarter Descemet's membrane endothelial keratoplasty (3/4-DMEK) technique to treat pseudophakic bullous keratopathy in the presence of a glaucoma drainage device (GDD) tube in the anterior chamber by reducing the risk of donor endothelial damage due to absence of donor endothelial cells overlying the GGD tube area.

METHODS

In this prospective case series, four eyes of three patients with stable glaucoma underwent 3/4-DMEK surgery for pseudophakic bullous keratopathy after GDD insertion. The patients were followed up to 24 ± 2.5 months postoperatively.

RESULTS

No intraoperative or postoperative complications were noted. The average central endothelial cell density (ECD) was 1093 ± 74 cells/mm² at 12 months postoperatively, corresponding to an ECD decrease of 58 (±6)% as compared to preoperative values. Average best-corrected visual acuity increased from finger counting before surgery to 20/60 (logMar 0.5) at 12 months after 3/4-DMEK and remained stable up to 24 months postoperatively. All corneas remained clear at the last available follow-up.

CONCLUSION

This case series demonstrates the technical feasibility of 3/4-DMEK in eyes with pseudophakic bullous keratopathy in the presence of a GDD tube. The absence of a donor DM and donor cells above the silicone tube excludes direct tube contact with the graft. Longer term studies are needed to show the effect of this modified graft pattern and dimensions on transplant survival.

Surgery for glaucoma in modern corneal graft procedures

Glaucoma is a common cause of vision loss after corneal transplantion and is considered a major risk factor for graft failure. Glaucoma may be present before corneal transplant surgery, or increased intraocular pressure may develop after keratoplasty in up to one-third of patients. Pre-existing glaucoma should be controlled before keratoplasty, either medically or surgically. For postkeratoplasty increase in intraocular pressure; identifying the risk factors allows appropiate follow-up and management. Patients undergoing anterior lamellar keratoplasty may take advantage of reduced rates of postkeratoplasty glaucoma. Glaucoma also complicates eyes with endothelial keratoplasties, mostly related to management of intraocular pressure spikes derived from anterior chamber air bubbles. Nevertheless, the severity is less, and the intraocular pressure is more easily controlled when compared with penetrating keratoplasty. Adequate management of glaucoma that develops before or after keratoplasty may save eyes from irreversible damage to the optic nerve and increase graft survival.

Comparison of Endothelial Keratoplasty Techniques in Patients With Prior Glaucoma Surgery: A Case-Matched Study

PURPOSE

To compare the outcomes of Descemet membrane endothelial keratoplasty (DMEK) with those of Descemet's stripping endothelial keratoplasty (DSEK) in eyes with prior glaucoma surgery.

DESIGN

Case-matched retrospective comparative case series.

METHODS

Setting/study population: 46 DMEK procedures were matched with 46 DSEK procedures at a single institution.

OBSERVATION PROCEDURES

cases were matched based on preoperative visual acuity, lens status, and surgical indication.

MAIN OUTCOME MEASUREMENTS

the outcome measurements included visual acuity improvement, primary and secondary graft failure, endothelial rejection, intraocular pressure (IOP) elevation, and the need for additional glaucoma intervention.

RESULTS

Best-corrected visual acuity (BCVA) improved by -0.89 logMAR in the DMEK group and -0.62 logMAR in the DSEK group (P = 0.005) at 1 year follow-up. Visual acuity was significantly better in the DMEK group at postoperative months 1, 3, and 12 and at last follow-up. The percentage of patients achieving 20/40 or better best-corrected visual acuity was higher in the DMEK group at all time points, notably 47% in the DMEK group versus 15% in the DSEK group at 1 year (P = 0.002). Secondary graft failure was lower in the DMEK group (DMEK 0% vs. DSEK 17%; P = 0.006). Primary graft failure rates and rebubling rates were similar. There were no differences in the rates of postoperative IOP elevation or in the need for additional glaucoma intervention.

CONCLUSIONS

In complex eyes with prior glaucoma surgery, DMEK offers faster visual recovery, better final visual acuity, and a lower rate of secondary graft failure compared to DSEK during the first postoperative year and beyond.

Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty in Eyes With a Glaucoma Drainage Device

PURPOSE

To evaluate the feasibility and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with a glaucoma drainage device (GDD).

DESIGN

Retrospective, interventional case series.

METHODS

Clinical outcomes of 23 DMEK procedures for bullous keratopathy (52%), failed previous transplant (39%), or Fuchs endothelial corneal dystrophy (9%) in 20 eyes (19 patients) with a GDD were retrospectively analyzed at 2 tertiary referral centers. Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD), postoperative complications, and graft survival.

RESULTS

Mean length of postoperative follow-up after DMEK was 19 (±17) months. Kaplan-Meier survival analysis showed an 89% cumulative graft success rate at 1 year postoperatively. At 1 year postoperatively (n = 15 eyes), BCVA improved by ≥2 Snellen lines in 11 eyes (73%) and remained stable in 4 eyes (27%). Donor ECD decreased by 37% (n = 14), 60% (n = 11), and 71% (n = 11) at 1, 6, and 12 months postoperatively, respectively. Postoperative complications up to 2 years postoperatively comprised pupillary block in 1 eye (successfully reversed by partial air removal), visually significant graft detachment requiring rebubbling in 5 eyes (22%), allograft rejection successfully reversed with topical steroids in 2 eyes (9%), secondary graft failure in 2 eyes (9%), and cataract in 1 of 3 phakic eyes (33%). Re-keratoplasty was required in 2 eyes (9%).

CONCLUSIONS

With specific surgical modifications, DMEK provided acceptable clinical outcomes when taking the complexity of these eyes into account. However, presence of a GDD may reduce graft survival times and may pose a risk for more frequent regrafting.

Association between corneal endothelial cell densities and elevated cytokine levels in the aqueous humor

Annual reduction rate of corneal endothelial cell density (ECD) varies among etiologies, however, the cause of chronic endothelial cell loss is still unknown. We recently reported the elevation of inflammatory cytokines in the aqueous humor (AqH) in eyes with bullous keratopathy and low ECD. To evaluate the association between ECD and aqueous cytokine levels, we collected a total of 157 AqH samples prospectively. The AqH levels of cytokines were measured and multivariate analyses were conducted to find the correlation between ECD, aqueous cytokine levels and clinical factors, such as number of previous intraocular surgeries and protein concentration in AqH. As a result, ECD was negatively correlated with specific cytokine levels, including IL-1α, IL-4, IL-13, MIP-1β, TNF-α and E-selectin (all P < 0.05). The aqueous cytokine levels showed different correlations with these clinical factors; the number of previous intraocular surgeries was associated with all cytokines except MIP-1α. The AqH protein concentration and the status of intraocular lens showed similar patterns of elevation of IL-1α, IL-4, IL-6, IL-8, IL-10, IL-13, IL-17A, MIP-1β, MCP-1, E-selectin, P-selectin and sICAM-1. In conclusion, elevation of AqH cytokine levels was associated with reduced ECDs. AqH cytokine levels showed significant correlations with clinical factors associated with low ECDs.

Glaucoma Mini-Shunt Implantation After Keratoplasty

PURPOSE

To report the outcomes of patients who underwent miniature glaucoma shunt implantation after secondary glaucoma due to keratoplasty.

MATERIALS AND METHODS

Prospective study of consecutive clinical cases who underwent mini-glaucoma shunt implantation following keratoplasty. In brief, a fornix-based conjunctival flap was performed, approximately 50% thickness scleral flap. Mitomycin C 0.025% placed under Tenon's capsule. A 25-G needle created entry for mini-shunt. Ex-PRESS model P-50 was inserted. Scleral flap and conjunctiva were closed with 10-0 Nylon. STATA 8.0 and SPSS software were used for statistical analysis.

RESULTS

Seventeen eyes of 17 patients with a mean age of 39.70 years (SD=18.33, range: 18 to 76). A total of 64.70% were male and 35.30% female. Eleven cases after penetrating keratoplasty, 3 cases after triple procedure, 2 after deep anterior lamellar keratoplasty, and 1 following endothelial keratoplasty. Most of the indications for keratoplasty were keratoconus in 9 cases (52.94%), 4 due to endothelial failure (23.52%), 3 cases of herpetic keratitis (17.64%), and 1 case of post-LASIK ectasia (5.88%). Mean preoperative intraocular pressure was 35.94 mm Hg with maximal medical therapy (SD=9.65, range: 18 to 55). Decreasing intraocular pressure to 12.76 mm Hg postoperatively (SD=2.51, range 10 to 18) (P=0.001). Mean follow-up after mini-glaucoma shunt implantation was 23.76 months (SD=8.73, range: 10 to 35 mo). Preoperative mean uncorrected distance visual acuity (UDVA) was 1.31±0.63 (20/408 Snellen) and postoperative mean UDVA was 0.85±0.40 (20/141 Snellen) (P=0.001). Preoperative mean corrected distance visual acuity (CDVA) was 0.83±0.76 (20/135 Snellen) and postoperative mean CDVA was 0.56±0.44 (20/72 Snellen) (P=0.032).

CONCLUSIONS

Ex-PRESS miniature glaucoma shunt could be an alternative treatment in postkeratoplasty glaucoma resistant to medical treatment. This technique may be helpful, in trying to avoid corneal damage produced by conventional glaucoma procedures.

Glaucoma after corneal replacement

Glaucoma is a well-known complication after corneal transplantation surgery. Traditional corneal transplantation surgery, specifically penetrating keratoplasty, has been slowly replaced by the advent of new corneal transplantation procedures: primarily lamellar keratoplasties. There has also been an emergence of keratoprosthesis implants for eyes that are high risk of failure with penetrating keratoplasty. Consequently, there are different rates of glaucoma, pathogenesis, and potential treatment in the form of medical, laser, or surgical therapy.

Aqueous shunts for glaucoma

BACKGROUND

Aqueous shunts are employed to control intraocular pressure (IOP) for people with primary or secondary glaucomas who fail or are not candidates for standard surgery.

OBJECTIVES

To assess the effectiveness and safety of aqueous shunts for reducing IOP in glaucoma compared with standard surgery, another type of aqueous shunt, or modification to the aqueous shunt procedure.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 8), MEDLINE Ovid (1946 to August 2016), Embase.com (1947 to August 2016), PubMed (1948 to August 2016), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to August 2016), ClinicalTrials.gov (www.clinicaltrials.gov); searched 15 August 2016, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 15 August 2016. We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 15 August 2016. We also searched the reference lists of identified trial reports and the Science Citation Index to find additional trials.

SELECTION CRITERIA

We included randomized controlled trials that compared various types of aqueous shunts with standard surgery or to each other in eyes with glaucoma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results for eligibility, assessed the risk of bias, and extracted data from included trials. We contacted trial investigators when data were unclear or not reported. We graded the certainty of the evidence using the GRADE approach. We followed standard methods as recommended by Cochrane.

MAIN RESULTS

We included 27 trials with a total of 2099 participants with mixed diagnoses and comparisons of interventions. Seventeen studies reported adequate methods of randomization, and seven reported adequate allocation concealment. Data collection and follow-up times varied.Four trials compared an aqueous shunt (Ahmed or Baerveldt) with trabeculectomy, of which three reported one-year outcomes. At one-year, the difference in IOP between aqueous shunt groups and trabeculectomy groups was uncertain (mean difference (MD) 2.55 mmHg, 95% confidence interval (CI) -0.78 to 5.87; 380 participants; very low-certainty evidence). The difference in logMAR visual acuity was also uncertain (MD 0.12 units, 95% CI -0.07 to 0.31; 380 participants; very low-certainty evidence). In two trials, the difference in visual field score was uncertain (MD -0.25, 95% CI -1.91 to 1.40; 196 participants; very low-certainty evidence). The mean number of antiglaucoma medications was higher in the aqueous shunt group than the trabeculectomy group in one trial (MD 0.80, 95% CI 0.48 to 1.12; 184 participants; low-certainty evidence). The effect on needing additional glaucoma surgery was uncertain between groups in two trials (risk ratio (RR) 0.24, 95% CI 0.04 to 1.36; 329 participants; very low-certainty evidence). In one trial, fewer total adverse events were reported in the aqueous shunt group than the trabeculectomy group (RR 0.59, 95% CI 0.43 to 0.81; 212 participants; very low-certainty evidence). No trial reported quality-of-life outcomes at one-year follow-up.Two trials that compared the Ahmed implant with the Baerveldt implant for glaucoma found higher mean IOP in the Ahmed group at one-year follow-up (MD 2.60 mmHg, 95% CI 1.58 to 3.62; 464 participants; moderate-certainty evidence). The difference in logMAR visual acuity was uncertain between groups (MD -0.07 units, 95% CI -0.27 to 0.13; 501 participants; low-certainty evidence). The MD in number of antiglaucoma medications was within one between groups (MD 0.35, 95% CI 0.11 to 0.59; 464 participants; moderate-certainty evidence). More participants in the Ahmed group required additional glaucoma surgery than the Baerveldt group (RR 2.77, 95% CI 1.02 to 7.54; 514 participants; moderate-certainty evidence). The two trials reported specific adverse events but not overall number of adverse events. Neither trial reported visual field or quality-of-life outcomes at one-year follow-up.One trial compared the Ahmed implant with the Molteno implant for glaucoma over two-year follow-up. Mean IOP was higher in the Ahmed group than the Molteno group (MD 1.64 mmHg, 95% CI 0.85 to 2.43; 57 participants; low-certainty evidence). The differences in logMAR visual acuity (MD 0.08 units, 95% CI -0.24 to 0.40; 57 participants; very low-certainty evidence) and mean deviation in visual field (MD -0.18 dB, 95% CI -3.13 to 2.77; 57 participants; very low-certainty evidence) were uncertain between groups. The mean number of antiglaucoma medications was also uncertain between groups (MD -0.38, 95% CI -1.03 to 0.27; 57 participants; low-certainty evidence). The trial did not report the proportion needing additional glaucoma surgery, total adverse events, or quality-of-life outcomes.Two trials compared the double-plate Molteno implant with the Schocket shunt for glaucoma; one trial reported outcomes only at six-month follow-up, and the other did not specify the follow-up time. At six-months, mean IOP was lower in the Molteno group than the Schocket group (MD -2.50 mmHg, 95% CI -4.60 to -0.40; 115 participants; low-certainty evidence). Neither trial reported the proportion needing additional glaucoma surgery, total adverse events, or visual acuity, visual field, or quality-of-life outcomes.The remaining 18 trials evaluated modifications to aqueous shunts, including 14 trials of Ahmed implants (early aqueous suppression versus standard medication regimen, 2 trials; anti-vascular endothelial growth factor agent versus none, 4 trials; corticosteroids versus none, 2 trials; shunt augmentation versus none, 3 trials; partial tube ligation versus none, 1 trial; pars plana implantation versus conventional implantation, 1 trial; and model M4 versus model S2,1 trial); 1 trial of 500 mm² Baerveldt versus 350 mm² Baerveldt; and 3 trials of Molteno implants (single-plate with oral corticosteroids versus single-plate without oral corticosteroids, 1 trial; double-plate versus single-plate, 1 trial; and pressure-ridge versus double-plate with tube ligation, 1 trial).

AUTHORS' CONCLUSIONS

Information was insufficient to conclude whether there are differences between aqueous shunts and trabeculectomy for glaucoma treatment. While the Baerveldt implant may lower IOP more than the Ahmed implant, the evidence was of moderate-certainty and it is unclear whether the difference in IOP reduction is clinically significant. Overall, methodology and data quality among existing randomized controlled trials of aqueous shunts was heterogeneous across studies, and there are no well-justified or widely accepted generalizations about the superiority of one surgical procedure or device over another.

Factors associated with graft survival and endothelial cell density after Descemet's stripping automated endothelial keratoplasty

Postoperative endothelial cell loss leads to graft failure after corneal transplantation, and is one of the important issues for long-term prognosis. The objective of this study was to identify clinical factors affecting graft survival and postoperative endothelial cell density (ECD) after Descemet’s stripping automated endothelial keratoplasty (DSAEK). A total of 198 consecutive Japanese patients (225 eyes) who underwent DSAEK were analysed using Cox proportional hazard regression and multiple linear regression models. The candidate factors included recipient age; gender; diagnosis; pre-existing iris damage state, scored based on its severity; the number of previous intraocular surgeries; graft ECD; graft diameter; simultaneous cataract surgery; surgeons experience; intraoperative iris damage; postoperative rebubbling; and graft rejection. Eyes with higher pre-existing iris damage score and more number of previous intraocular surgery had a significantly higher risk of graft failure (HR = 8.53; P < 0.0001, and HR = 2.66; P = 0.026, respectively). Higher pre-existing iris damage score, lower graft ECD, and smaller graft diameter were identified as significant predisposing factors for lower postoperative ECD. The results show that iris damage status before DSAEK may be clinically useful in predicting the postoperative course. Avoiding intraoperative iris damage, especially in eyes with low ECD can change the prognosis of future DSAEK.

Graft failure and intraocular pressure control after keratoplasty in iridocorneal endothelial syndrome

PURPOSE

To describe and compare graft survival and intraocular pressure (IOP) control after penetrating keratoplasty (PK) and Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with iridocorneal endothelial (ICE) syndrome.

DESIGN

Retrospective case series.

METHODS

Multicenter study conducted at the Singapore National Eye Centre (SNEC) and Price Vision Group. Twenty-nine consecutive eyes with ICE syndrome that underwent keratoplasty between 1991 and 2011 were identified from the SNEC transplant database and Price Vision Group patient database and the following data extracted: demographics, graft failure, IOP indices, and glaucoma treatment pre- and postkeratoplasty. The main outcome measures were graft failure and need for additional IOP-lowering treatment after keratoplasty.

RESULTS

The mean follow-up duration was 7.0 ± 4.9 years in the PK group (n = 17) and 4.0 ± 2.6 years in the DSAEK group (n = 12). After a mean of 4.1 ± 3.1 years, 37.9% of grafts (11/29) failed: 7 PK compared to 4 DSAEK (P = .72). The graft failure rate was 50% in eyes with prekeratoplasty glaucoma surgery vs 31.6% in those without (P = .43). Additional glaucoma treatment was required in 37.9% of eyes (11/29): 41.2% of PK eyes and 50% of DSAEK eyes (P = .28) Eyes that had undergone glaucoma surgery before keratoplasty were less likely to require escalation of IOP-lowering therapy postkeratoplasty (9.1% vs 50%, P = .03).

CONCLUSIONS

One-third of grafts failed after keratoplasty for ICE syndrome at a mean duration of 4 years and additional IOP-lowering treatment was required in 37.9%. Both PK and DSAEK had similar outcomes with regard to graft failure and IOP control.

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.

Ahmed glaucoma valve in eyes with preexisting episcleral encircling element

BACKGROUND

To describe the use of Ahmed glaucoma valve (AGV) in the management of intractable glaucoma in eyes with a preexisting episcleral encircling element.

MATERIALS AND METHODS

This is a retrospective, consecutive, noncomparative study. The study included 12 eyes of 12 patients with a preexisting episcleral encircling element that underwent implantation of silicone AGV to treat intractable glaucoma during January 2009 to September 2010.

RESULTS

The mean patient age was 25.6 (standard deviation 17.1) years. Five (41.6%) patients were monocular. The indications for AGV were varied. The mean duration between placement of episcleral encircling element and implantation of AGV was 30.5 (33.8) months. The mean follow-up was 37.4 (22.9) weeks. Preoperatively, the mean intraocular pressure (IOP) was 31.4 (7.9) mmHg and the mean antiglaucoma medications were 2.8. At the final postoperative follow-up, the mean IOP was 12.5 (3.5) mmHg and the mean number of antiglaucoma medications was 0.8 (P < 0.001). The complications observed over the follow-up period did include corneal graft failure in three eyes, tube erosion in two eyes and rhegmatogenous retinal detachment in one eye.

CONCLUSION

AGV is an effective option in the management of intractable glaucoma in eyes with a preexisting episcleral encircling element keeping in mind the possibility of significant postoperative complications.

Clinical outcomes of Ahmed Glaucoma valve in posterior segment versus anterior chamber

PURPOSE

To compare the intermediate-term intraocular pressure (IOP) control and complication profile of the Ahmed Glaucoma Valve (AGV) implanted posteriorly through the pars plana in eyes undergoing concurrent pars plana vitrectomy (PPV) with device implantation in the anterior chamber (AC) in nonvitrectomized eyes.

METHODS

: We retrospectively reviewed the medical records of 31 case eyes (30 patients) with refractory glaucoma that underwent posterior implantation of AGV after complete PPV and compared them to 31 control eyes (31 patients) with refractory glaucoma that underwent implantation of AGV in the AC. Case-control patients were matched one-to-one on the basis of principal glaucoma diagnosis. All surgeries were performed at 1 institution using a silicone-plate device. Success was defined as intraocular pressure (IOP)≥ 5 mm Hg and ≤ 21 mm Hg with or without glaucoma medications at final follow-up, no additional glaucoma surgery, no removal of the implant, and no loss of light perception.

RESULTS

The average follow-up was 20.9 months (range, 6 to 54 mo) for the posterior group and 20.5 months (range, 4 to 48 mo) for the anterior group. The reduction in IOP was similar in both groups at all postoperative time points. The number of postoperative glaucoma medications in both groups was not statistically different at final follow-up. Success rates at final follow-up were identical, 83.9% in both groups, and Kaplan-Meier survival curve analysis showed no significant difference between the 2 groups (P=0.96). Postoperative complications were similar between the 2 groups, except there were more instances of early postoperative flat AC in the anterior group than the posterior group (P=0.01).

CONCLUSIONS

The AGV can similarly control IOP in the majority of cases, whether the tube is placed in the posterior segment after PPV or in the AC of nonvitrectomized eyes.

Five-year outcomes of eyes with glaucoma drainage device and penetrating keratoplasty

PURPOSE

To investigate intraocular pressure (IOP) control and corneal graft survival rates in eyes with glaucoma drainage device (GDD) implantation and penetrating keratoplasty (PK) and 5 years of follow-up data.

DESIGN

Retrospective review.

METHODS

We performed a review of records of all patients who underwent both GDD placement and PK at our institution between January 1, 1988 and December 31, 2003. Twenty-eight eyes of 27 patients were studied. Glaucoma outcome was assessed by postoperative IOP, number of glaucoma medications, and need for further glaucoma surgery. Corneal grafts were assessed for clarity.

RESULTS

All eyes had GDD placement in the anterior chamber. The mean pre-GDD IOP was 28.8 ± 10.3 mm Hg on a mean of 2.6 ± 0.8 glaucoma medications. At 5-year follow-up, the mean IOP was 13.0 ± 5.9 mm Hg on a mean of 0.9 ± 1.0 glaucoma medications. GDD implantation successfully controlled glaucoma in 96%, 86%, 79%, 75%, and 71% of eyes at 1, 2, 3, 4, and 5 years, respectively. Grafts remained clear in 96%, 82%, 75%, 57%, and 54% of eyes at 1, 2, 3, 4, and 5 years, respectively. Failure of glaucoma outcome or graft survival was associated with prior intraocular surgeries.

CONCLUSIONS

Our data suggests that GDD placement can provide glaucoma control in a high percentage (71%) of eyes with PK even at 5 years. Furthermore, the success of PK in eyes with GDD remains reasonable (54%) at 5 years. IOP control and graft survival rates are comparable with earlier published studies with shorter follow-up or tube placement in the vitreous cavity.

Descemet stripping with automated endothelial keratoplasty: A comparative study of outcome in patients with preexisting glaucoma

PURPOSE

To compare postoperative complications after Descemet stripping with automated endothelial keratoplasty (DSAEK) in patients with and without glaucoma.

METHODS

For this retrospective study a series of 298 DSAEK cases performed at the Doheny Eye Institute were taken, we compared postoperative complications in eyes with glaucoma on medication (55) or with previous glaucoma surgeries (64) with a time-matched group of all other DSAEK cases (179, control).

RESULTS

With a mean follow-up of 1.85 ± 1.12 years, the complication rates were 12.8%, 11.1%, and 26.8% for postoperative graft detachment, graft failure, and IOP elevation, respectively. Graft detachment was an independent risk factor for graft failure (odds ratio OR = 12.35, 95% confidence interval CI [5.46-27.90], P < 0.001). Graft detachment was not associated with either history of glaucoma or glaucoma surgery (P > 0.05). Glaucoma on medication had no increased risks of graft failure compared to normal eyes (P = 0.38). However, increased risk of failure was seen in eyes with prior incisional glaucoma surgeries (OR = 4.26, 95% CI [1.87-9.71], P < 0.001). Medically managed glaucoma has increased risks of postoperative IOP elevation (OR = 2.39, 95% CI [1.25-4.57], P = 0.013), whereas surgically managed glaucoma has no significant elevation (P = 0.23). Elevation of IOP was not significantly correlated with graft failure (P = 0.21).

CONCLUSION

DSAEK is the preferred treatment for corneal endothelial dystrophy. We observed that having glaucoma or glaucoma surgery is not associated with graft detachment. A history of glaucoma surgery and postoperative graft detachment appeared to be important risk factors for graft failure. And more studies are indicated to study long-term IOP evolution in post-DSAEK patients and its association with graft survival.

Endothelial keratoplasty: fellow eyes comparison of Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty

PURPOSE

To evaluate patients' perspectives and outcomes of 2 different endothelial keratoplasty (EK) techniques performed in the fellow eyes of the same patients: Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

In this fellow eye, comparative, retrospective case series, the records of 15 patients who underwent DSAEK in 1 eye and DMEK in the fellow eye and completed at least 1 year of follow-up after the second procedure were reviewed. Visual outcomes and endothelial cell density were assessed. Patient satisfaction was evaluated using a subjective questionnaire.

RESULTS

At 12 months postoperatively, the mean best spectacle-corrected visual acuity (BSCVA) in the DMEK group was 0.07 logarithm of the minimum angle of resolution (20/24) and 0.20 logMAR (20/32) in the DSAEK group (P = 0.004). The majority of the patients (85%) perceived better visual quality in the DMEK eye. Furthermore, 62% preferred or would recommend DMEK to a friend or relative, whereas 15% preferred DSAEK and 23% reported no preference between the surgical procedures. The 1-year endothelial cell loss and the perceived discomfort level during the postoperative period were comparable for the 2 procedures.

CONCLUSIONS

The majority of the patients preferred or would recommend the DMEK procedure. Faster visual recovery and better final visual acuity were the main benefits of the DMEK technique.

Glaucoma after penetrating keratoplasty: incidence, risk factors, and management

Purpose. To report the incidence and risk factors for postkeratoplasty glaucoma (PKG), as well as its management. Subjects and Methods. 122 eyes, (43% with pseudophakic and aphakic bullous keratopathy (PABK)) which underwent penetrating keratoplasty (PK), were analyzed. Results. The rate of PKG development was 34% within 39 months of follow-up. PABK, corneal perforations, keratitis, and previous high intraocular pressure (PHIOP) were high risk factors for PKG. Glaucoma was controlled medically in 62% of PKG cases. Surgery (Ex-PRESS shunt in 63%) and diode laser cyclophotocoagulation were applied in others (38%). The rate of postoperative complications and graft survival was similar in eyes with and without PKG. Conclusion. PHIOP, preoperative diagnoses other than keratoconus, and corneal dystrophies were highly associated with PKG. Ex-PRESS shunts were effective in refractory PKG. If glaucoma is controlled, it is possible to obtain similar rates of graft survival and postoperative complications in eyes with and without PKG.

Baseline factors related to endothelial cell loss following penetrating keratoplasty

OBJECTIVE

To identify baseline (donor, recipient, and operative) factors that affect endothelial cell loss following penetrating keratoplasty for a moderate-risk condition (principally Fuchs dystrophy or pseudophakic or aphakic corneal edema).

METHODS

In a subset (n = 567) of Cornea Donor Study participants, preoperative and postoperative endothelial cell densities (ECDs) were determined by a central reading center. Multivariate regression analyses were performed to examine which baseline factors correlated with ECD over time.

RESULTS

Larger grafts (P < .001), younger donor age (P < .001), and female donor (P = .004) were significantly associated with higher ECD during follow-up. Median endothelial cell loss at 5 years was 68% for grafts larger than 8.0 to 9.0 mm in diameter, 75% for grafts 7.0 mm to smaller than 8.0 mm in diameter, and 74% for grafts 8.0 mm in diameter. Grafts from female donors experienced a 67% cell loss compared with a 72% cell loss among grafts from male donors. Method of tissue retrieval, donor cause of death, history of diabetes, and time from death to preservation or to surgery were not significantly associated with changes in ECD over time.

CONCLUSIONS

Following penetrating keratoplasty for endothelial dysfunction conditions, larger donor graft size, younger donor age, and female donor were associated with higher ECD over 5 years. These data warrant exploring the possibility that similar associations may exist following endothelial keratoplasty.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00006411.