1. 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

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. 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):
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):
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 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

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

5. 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

6. 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

7. 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

8. 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

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
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 = (univariate)
Additional intra-operative procedures during DSAEK
Odds ratio = 18.2, p = (univariate)
Odds ratio = 12.2, p = (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 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