Transcript Long Term Corneal Endothelial Cell Loss in eyes with Clear Grafts

Long Term Corneal Endothelial Cell
Loss in eyes with Clear Grafts after
Penetrating Keratoplasty for
Keratoconus
Dr. Gerald Zaidman1,2 , Angela Vong1
1New
York Medical College, Valhalla, NY; 2 Ophthalmology, Westchester Medical Center,
Valhalla, NY
The authors have no financial interest in the subject matter
of this poster.
INTRODUCTION
Endothelial trauma from ocular surgery, specifically
penetrating keratoplasty, is known to significantly
reduce endothelial cell counts (ECC). Poor vision,
contact lens intolerance, and scarring are indications
for corneal transplant surgery (PKP) in keratoconus
(KCN). After PKP, there can be a decreased ECC in
the recipient cornea. To date we know of no study that
measures ECC loss years after PKP for KCN. Our
study aims to measure long-term ECC loss after PKP
for KCN.
METHODS
Endothelial cell counts were measured in eyes that had
PKP performed by one surgeon, GWZ, from 1994 – 2008
for KCN. Counts were done using Konan NSP-7700
Specular Microscopy. Only eyes with clear grafts were
analyzed. ECC was compared to the original donor ECC.
Eyes were divided into groups based on years following
PKP:
- Group A: 1 – 2 years
- Group B: 3 – 5 years
- Group C: 6 – 9 years
- Group D: 10 – 14 years
We also analyzed eyes that had cataract surgery, refractive
surgery, or more than 2 rejection episodes after PKP.
RESULTS
Figure 1.
Keratoconus
Figure 2.
Eye following Penetrating Keratoplasty
RESULTS
Endothelial cell counts were performed on 63 eyes.
Patients averaged 46 years old, ranging from 29 – 66
years old.
Group
Years after
surgery
No. of Eyes
Mean cell loss
Median Cell
loss
A
1–2
18
27+22%
20%
B
3–5
18
46+16%
48%
C
6–9
15
56+17%
59%
D
10 – 14
12
62+14%
64%
Figure 3. Percentage of Endothelial Cell Loss Following PKP in Uncomplicated Eyes
Figure 4.
ECC 1-2 Years after PKP
Figure 5.
ECC 3-5 Years after PKP
Figure 6.
ECC 6-9 Years after PKP
Figure 7.
ECC 10-14 Years after PKP
Figure 5. Percentage of Endothelial Cell Survival following PKP
RESULTS
No. of eyes
Mean cell
loss
Median cell
loss
Cataract sx
after PKP
7
63+13%
63%
Refractive sx
after PKP
7
58+17%
64%
>2 rejection
episodes
8
59+20%
63%
Figure 6. Penetrating Keratoplasties analyzed with other
surgeries and rejection episodes
RESULTS
Best corrected visual acuity of 60 eyes were 20/40
or better. 3 eyes had poor vision; one due to
cystoid macular edema and 2 in a handicapped
patient who could not be refracted.
CONCLUSIONS
There is continuing long term ECC loss years
after PKP with the greatest loss in the first 5
years following surgery. Corneal clarity and
visual acuity were not affected. Best
corrected visual acuity were 20/40 or better in
nearly all eyes. Cataract surgery, refractive
surgery, and resolved rejection episodes also
led to endothelial cell loss but did not affect
corneal clarity.
REFERENCES
1)
Ham L, Luijk CV, Dapena I, Wong TH, Birbal R, Wees JVD,
Melles GRJ. Endothelial Cell Density after Descemet Membrane
Endothelial Keratoplasty: 1- to 2-Year Follow-Up. Amer J of
Ophthalmology 2009; 148: 521-527
2)
Patel SV, Hodge DO, Bourne WM. Corneal Endothelium and
Postoperative Outcomes 15 Years After Penetrating Keratoplasty.
Trans Am Ophthalmol Soc 2004; 102: 57-65
3)
Ing JJ, Ing HH, Nelson LR, Hodge DO, Bourne WM. Ten-Year
Postoperative Results of Penetrating Keratoplasty.
Ophthalmology 1998; 105(10): 1855-1865
4)
Zacks CM, Abbot RL, Fine M. Long-Term Changes in Corneal
Endothelium After Keratoplasty. Cornea 1990; 9(2)