97th DOG Annual Meeting 1999
P50
MORPHOLOGIC RESULTS OF ECCENTRIC HOMOLOGOUS PENETRATING KERATOPLASTY
T. Riedel, G. O. H. Naumann
Background: Due to unfavorable optical and immunological consequences an eccentric position of the corneal transplant is limited to curative or tectonic indications. The purpose of this study was to examine the morphological results of eccentric homologous penetrating keratoplasty (PK) with respect to diagnosis as well as position and size of the corneal graft.
Patients and Methods: Between 01/1989 and 10/1997, 122 eccentric homologous PKs were carried out on 96 eyes of 96 patients (average age 60±18 years, 10x nonmechanical trephination). The PK was done à chaud in 104 patients (85%) because of a corneal ulcer (36 previous PK, 21 areactive/rheumatic, 20 herpetic, 15 bacterial, 12 other). A corneal perforation was present in 44 patients (36%). Elective PK was performed in 6 eyes with corneal scars, 7 eyes with ectatic corneal diseases (ECT) and 5 others. Using postoperative slides showing a frontal slit-lamp view of the cornea in a standardized manner (x20) the following parameters were quantified: the graft diameter (GD) and transparency, the distance of the geometric center of the cornea from the central trephination (DIS) as well as from the geometric center of the graft). 25% of grafts were classified as "eccentric peripheral" PK (EPPK) with the optical axis through the host cornea, 75% as "eccentric central" PK (ECPK) with the optical axis through the graft.
Results: The mean GD of ulcers was 6.1±1.6 mm, of scars 7.1±0.6 mm, of ECT 7.9±0.4 mm, and of others 7.7±2.4 mm. In EPPK (only ulcers, 5.0±1.7 mm) the mean GD was significantly smaller than in ECPK (78% ulcers, 7.0±1.3 mm) (p<0.001). The decentration of EPPK (3.5±1.1 mm) was significantly higher than that of ECPK (1.4±0.8 mm) (p<0.001). DIS of EPPK was +1.3±0.9 mm, of ECPK it was -2.0±1.0 mm. During the average follow-up period of 25±29 months, 26 eccentric Re-PKs in 17 patients (16 in 12 patients within three months) and 8 central Re-PKs became necessary. Six patients had tectonic conjunctival grafts, 4 patients had enucleation. 46%/58% of grafts in EPPK/ECPK were cristal clear, 18%/15% showed minor opacities and 36%/27% were completely cloudy. 45%/75%/100% of ulcers/scars/ECT were cristal clear, 18%/25%/0% showed minor opacities and 37%/0%/0% were completely cloudy. Mean graft decentration increased from 1.4±1,1 mm over 1.7±1.2 mm to 2.2±1.4 mm with increasing stage of cloudiness.
Conclusion: The diagnosis leading to eccentric PK has the major impact on the long-term graft transparency. In addition, increasing decentration of the graft seems to be associated with increasing probability of clouding.
Department of Ophthalmology, University of Erlangen-Nürnberg, Schwabachanlage 6, D-91054 Erlangen
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