Corneal graft survival and intraocular pressure control after Descemet stripping automated endothelial keratoplasty in eyes with pre-existing glaucoma 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 Singapore National Eye Centre Singapore Eye Research Institute

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. Curr Opin Ophthalmol 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].

Methods Retrospective case series Inclusion criteria DSAEK 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

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

Results Value % Number of eyes, patients 47, 46 Age at DSAEK (mean ± SD) 66.6 ± 9.4 Gender (male), Race (Chinese) 24, 41 51.1, 87.2 Duration of follow-up, months 27.3 ± 8.5 Indications for DSAEK PBK with PCIOL PBK with ACIOL BK post LPI PBK with previous LPI Failed PK Fuchs endothelial dystrophy Posterior polymorphous dystrophy BK post glaucoma filtration surgery 11 4 3 5 1 23.4 8.5 6.4 10.6 2.1 Pre-DSAEK visual acuity 6/60 or worse 6/12 or better 32 1 68.1 2.1 Pre-DSAEK IOP (mmHg) 13.9 ± 4.3 Additional intraoperative procedures 16 34.0

Results Value % Pre-existing glaucoma diagnoses Acute primary angle closure Primary angle closure Primary angle closure suspect Primary angle closure glaucoma Primary open angle glaucoma Secondary angle closure glaucoma Secondary open angle glaucoma Ocular hypertension Angle closure Secondary glaucoma 2 4 5 7 3 6 18 24 4.3 8.5 10.6 14.9 6.4 12.8 38.3 51.1 Duration of glaucoma diagnosis (months) 75.4 ± 69.3 IOP lowering interventions pre-DSAEK LPI pre-DSAEK On at least 1 topical IOP medication No. of topical IOP medications Glaucoma filtration surgery pre-DSAEK Trabeculectomy Trabeculectomy with 5-FU Trabeculectomy with MMC Glaucoma drainage device Trabeculectomy + GDD 17 28 0.94 ± 0.96 14 5 1 6 36.2 59.6 29.8

Post DSAEK VA and IOP Results Value % Post DSAEK visual acuity Change in VA (Snellen lines) Improvement ≥ 2 Snellen lines Improvement < 2 Snellen lines Deprovement ≥ 2 Snellen lines VA of 6/12 or better at last follow-up Compared to pre DSAEK 5.4 ± 3.7 36 11 24 76.6 23.4 51.1 p<0.001 Post DSAEK IOP indices Post DSAEK mean IOP (mmHg) Lowest post DSAEK IOP (mmHg) Highest post DSAEK IOP (mmHg) Range of post-DSAEK IOP (mmHg) Change in IOP (mmHg) 16.0 ± 2.5 9.2 ± 2.6 27.4 ± 8.9 18.2 ± 9.6 2.1 ± 4.1 p=0.006

Graft failures Results Value % Number of DSAEK graft failures Number of repeat DSAEK Number of second DSAEK graft failures Interval to graft failure (months) 8 3 1 12.8 ± 7.0 17 37.5 33.3 Graft failure reasons Endothelial rejection Subsequent intra-ocular procedures Repositioning of IOL Trabeculectomy complicated by gross hyphaema Central graft-host dislocation Cytomegalovirus endothelitis 4 2 1 Control group No. of eyes undergoing DSAEK in the same time frame, by same surgeons, without pre-existing glaucoma No. of graft failures Compared to eyes with glaucoma 137 11 8 p=0.08

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

IOP treatment post DSAEK Results Value % On at least 1 topical medication post DSAEK Compared to pre DSAEK Requiring fewer topical medications post DSAEK Requiring additional IOP lowering treatment Requiring additional topical medication(s) only Requiring glaucoma filtration surgery only Requiring additional medication(s) and surgery Interval from DSAEK and glaucoma surgery (months) No. of topical medications post DSAEK No. of additional topical medications post DSAEK 36 3 29 21 2 6 9.3 ± 6.9 2.0 ± 1.5 1.1 ± 1.4 74.5 p=0.05 6.4 61.7 72.4 6.9 20.7 p<0.001 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)

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

LIMITATIONS CONCLUSIONS 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