Desmond QUEK 1 , Tina WONG 1,2 , Donald TAN 1,2 , Jodhbir MEHTA 1,2,3

1. Corneal graft survival and intraocular pressure control after Descemet stripping automated endothelial keratoplasty in eyes with pre-existing glaucoma Singapore National Eye Centre Singapore Eye Research Institute Desmond QUEK1, Tina WONG1,2, Donald TAN1,2, Jodhbir MEHTA1,2,3 1Singapore National Eye Centre and Singapore Eye Research Institute 2Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore 3Clinical Sciences, Duke-NUS Graduate Medical School The authors have no financial interest in the subject matter of this e-poster

2. Background • DSAEK now the procedure of choice for endothelial dysfunction1-3 • Reports on effect of DSAEK on IOP control and graft failure in eyes with pre-existing glaucoma limited • Incidence of post-DSAEK IOP elevation 45%4 • Graft failure rates higher in eyes with prior glaucoma filtration surgery or tube shunts5 • Aim • To describe the effect of DSAEK on IOP control and corneal graft survival in Asian eyes with pre-existing glaucoma or ocular hypertension • 1. Koenig SB, Covert DJ. Early results of small-incision Descemet stripping and automated endothelial keratoplasty. Ophthalmology 2007;114(2):221-6. • 2. Price MO, Price FW. Descemet stripping endothelial keratoplasty. CurrOpinOphthalmol 2007;18(4):290-4. • Bahar I, Kaiserman I, McAllum P, Slomovic A, Rootman D. Comparison of posterior lamellar keratoplasty techniques to penetrating keratoplasty. Ophthalmology 2008;115(9):1525-33. • Vajaranant TS, Price MO, Price FW, Gao W, Wilensky JT, Edward DP. Visual acuity and intraocular pressure after Descemet stripping endothelial keratoplasty in eyes with and without preexisting glaucoma. Ophthalmology 2009;116(9):1644-50. • Letko E, Price DA, Lindoso EM, Price MO, Price FW, Jr. Secondary Graft Failure and Repeat Endothelial Keratoplasty after Descemet Stripping Automated Endothelial Keratoplasty. Ophthalmology 2010 Sep 22 [Epub ahead of print].

3. Methods • Retrospective case series • Inclusion criteria • Consecutive eyes with pre-existing glaucoma or OHT undergoing DSAEK • Minimum follow-up duration of 12 months • DSAEK • By 5 surgeons • Standard surgical technique • Donor graft inserted via taco-folded or Sheets glide insertion technique • Post-op prednisolone forte 1% q3H gradual taper • Main outcome measures • Graft failures • Additional IOP lowering treatment post DSAEK

4. Variables examined • Demographics • Duration of f/u • DSAEK indications • Glaucoma diagnoses • Duration of glaucoma • Pre-DSAEK • VA • IOP • Glaucoma treatment • Additional intra-op procedures • Phacoemulsification • Synechiolysis • ACIOL exchange • Vitrectomy • Post-DSAEK • VA • Mean post-op IOP • Change in mean IOP • IOP range

7. Post DSAEK VA and IOP

8. Graft failures

9. Kaplan-Meier curve for graft survival • KM estimated probability of graft survival at • 1 year = 100% • 2 years = 94.2% • Risk factors for graft failure • None identified

10. IOP treatment post DSAEK Risk factors for need for additional IOP lowering treatment • No pre DSAEK glaucoma filtration surgery • Odds ratio = 10.8, p = 0.002 (univariate) • Additional intra-operative procedures during DSAEK • Odds ratio = 18.2, p = 0.008 (univariate) • Odds ratio = 12.2, p = 0.033 (multivariate)

11. Discussion • Eyes that had undergone glaucoma surgery pre-DSAEK were less likely to require additional IOP lowering treatment post-DSAEK • Suggests that pre-DSAEK glaucoma filtration surgery is able to adequately control post-DSAEK IOP elevations in majority of eyes • Eyes that underwent additional intraoperative procedures during DSAEK were more likely to require additional IOP-lowering therapy post-DSAEK • Additional procedures presumably incited additional post-operative inflammation, or caused further direct damage to the trabecular meshwork, leading to post-DSAEK IOP rise • Monitoring of glaucoma progression remains a challenge in eyes with corneal decompensation secondary to endothelial dysfunction • Perimetry results pre-DSAEK are seldom reliable nor accurate • Optic disc is often not clearly visualized • Angle assessment hindered by peripheral corneal opacification • In our study, mean highest IOPs of 27.4 ± 8.9 and a wide range of IOP fluctuation of 18.2 ± 9.6 mm Hg were observed post-DSAEK • However, the mean rise in IOP post-DSAEK was modest, with an overall mean increase of 2 mm Hg • Prompt and efficient lowering of raised IOP post-DSAEK could explain for the overall low rise in IOP • Efforts should be made to reduce raised IOP in post-DSAEK glaucomatous eyes, to prevent progression of glaucomatous optic nerve damage

12. LIMITATIONS • Retrospective • Small sample size • Lack of control group • Non-standardization of glaucoma treatment protocols • Further prospective randomized controlled studies will be required to better elucidate • True effect on intraocular pressure control • Glaucoma progression CONCLUSIONS • With prompt and appropriate intervention, IOP in glaucomatous eyes undergoing DSAEK can be controlled with minimal increase post-DSAEK • Glaucomatous eyes without prior filtration surgery and eyes that underwent additional intraoperative procedures during DSAEK are more likely to require additional IOP-lowering therapy • These eyes should be carefully monitored, and IOP-lowering therapy promptly instituted to prevent possible progression of glaucoma