Clinical investigationsCorneal Endothelial Cell Changes Twenty Years After Penetrating Keratoplasty
Introduction
Penetrating keratoplasty (PK) is a very common form of corneal transplantation. Corneal clarity following PK depends on the maintenance of the endothelial cells in the transplanted cornea. In some cases, the endothelial cells did not decrease after PK;1 in others, a decrease was reported.2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 There are a few reports about endothelial cell loss during a long postoperative period.3, 4, 5, 6, 7, 8 Endothelial cell loss occurred for several years and rapidly in the first year postoperatively.8, 9, 10, 11, 12 The rate of endothelial cell loss was reported to be 10.4–17.0% at 2 weeks after PK, 16.0% at 1 month, 18.3–33.0% at 3 months, 39.4% at 6 months, and 33.6–48.2% at 12 months.8, 9, 10, 11, 12 During the long postoperative period, the rate of endothelial cell density loss per year was reported at 150% by 2 months after PK, 20% between 2 months and 2 years, 7.3% between 2 and 5 years, and 1.3% between 5 and 20 years.3 The rate of endothelial cell density loss per year was reported at 4.2% between 5 and 10 years after PK.8
We evaluated the corneal endothelial cell density only in cases showing clear cornea for 20 years or longer after PK.
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Materials and Methods
We made a retrospective study of the records of 15 PK surgery patients who showed clear cornea for 20 years or longer after PK. The surgery had been performed at the Tokyo University Hospital between July 1970 and February 1978. Endothelial cell density was measured at 10 and 20 years following PK. These 15 transplants were performed on 13 patients (9 male and 4 female patients) (Table 1). The causative lesion was keratoconus in 10 eyes and herpetic keratitis in 5 eyes. In Table 1, cases 2 and
Results
The overall endothelial cell density averaged 998 ± 343 cells/mm2 (range, 645–1,980 cells/mm2) 10 years after PK, and 852 ± 245 cells/mm2 (range, 622–1,569 cells/mm2) 20 years after PK (Table 2). The rate of endothelial cell density loss had averaged 12.1 ± 16.3% over the last 10 years.
The endothelial cell density 10 years after PK averaged 879 ± 162 cells/mm2 (range, 645–1,124 cells/mm2) in keratoconus eyes and 1,235 ± 497 cells/mm2 (range, 779–1,980 cells/mm2) in herpetic keratitis eyes. The
Discussion
Owing to recent developments in surgical techniques, materials, and postoperative management, indications for PK have been extended to high-risk patients with conditions such as regrafting, bullous keratopathy, or chemical burn. One of the most important factors that effects the clinical outcome of PK is still allograft rejection.13 As high-risk patients are more likely to suffer from allograft rejection than low-risk ones, their outcomes after PK have not been good.13
In this study, we
Acknowledgements
A Japanese version of this paper was published in Rinsho Ganka (Jpn J Clin Ophthalmol) 2001;55:685–9. With the permission of Igaku Shoin, the publisher of Rinsho Ganka, it appears here in a modified form after peer review and editing for The Japanese Journal of Ophthalmology.
References (18)
- et al.
Long-term changes in corneal endothelium following penetrating keratoplasty. A specular microscopic study
Ophthalmology
(1983) - et al.
Endothelial morphology in long-term keratoconus corneal transplants
Ophthalmology
(1981) - et al.
Ten-year postoperative results of penetrating keratoplasty
Ophthalmology
(1998) - et al.
Ten-year postoperative results in penetrating keratoplasty
Opthalmology
(1982) One-year observation of transplanted human corneal endothelium
Ophthalmology
(1980)- et al.
A 10-year review of penetrating keratoplasty
Jpn J Ophthalmol
(2000) - et al.
The prognosis for keratoplasty in keratoconus
Ophthalmology
(1982) - et al.
Corneal transplantation for herpes simplex keratitis
Am J Ophthalmol
(1983) Specular microscopic study of cases treated with penetrating keratoplastymorphological changes in the endothelium
Nippon Ganka Gakkai Zasshi (Acta Soc Ophthalmol Jpn)
(1988)