Eye (1989) 3, 48-55 Large Corneal Grafts can be Successful C. M. KIRKNESS, L. A. FICKER, N. S. C. RICE, A. DMcG. STEELE London Summary Seventeen grafts of 10 mm in diameter or larger have been performed on 16 eyes of 15 patients. The major indications for surgery were infections or perforations or both. Follow-up has ranged from 8 - 54 months (mean 26.4). The 4 year survival probability was 0.64. Although the procedure was successful in saving all but one eye and restored useful vision in the majority, complications including cataract, glaucoma, graft rejection episodes and infections were encountered. The management of these complications is described. At final review, 13 eyes had clear grafts including those in whom regraft had been performed. These results have only been achieved by close co-operation between patients and the medical team responsible for their care. Traditional wisdom cautions against per­ examples are quoted of whole corneal trans­ forming large corneal grafts because of the plants. Recently, Guildford7 has produced risks of allograft rejection. This is likely disappointing results for such grafts. This because of the large antigen load provided, paper aims to identify possible indications for particularly so when one considers that the large penetrating grafts and to describe their Langerhans cells are only found in the management and complications. peripheral cornea,l and the proximity to the vascular tissue of the limbus.2 When corneas Patients and methods are transplanted into densely vascularised tis­ Corneal grafts in excess of 9.5 mm in diamter sue it is known that the rejection rate closely have been designated as large grafts. This approximates to rejection rates in other per­ definition is appropriate since the wound fused tissues.2 An additional problem antici­ edge will be a maximum of 1 mm inside the pated would be destruction of or damage to limbus and may extend beyond it; and the the drainage angle of the anterior chamber sutures will pass not only through the limbus when the graft size exceeded 10 mm in but may invade the angle of the anterior diameter. There are, however, instances chamber. The patients described form a con­ when large grafts may become necessary secutive series under the care of the surgeons when the eye is to be saved and visual poten­ of Corneal Clinic, Moorfields Eye Hospital, tial preserved. Young and Watson have but the surgery was performed by one sur­ described the use of large lamellar grafts geon (CMK). Only patients with a minimum when there is severe sclero-keratitis.3 Tic04 follow-up of 6 months are included. None of reported whole (10 mm) corneal transplants the donor material nor recipients were tissue and Du,s and Casey6 have described the matched. technique for keratoplasty in infected eyes without specifically dealing with the question Surgical technique of large penetrating grafts although some The surgical technique was based upon gen- From Corneal Clinic, Moorfields Eye Hospital, City Road, London. Correspondondence to: Mr CM Kirkness, FRCS, Dept of Clinical Ophthalmology, Institute of Ophthalmol­ ogy, Moorfields Eye Hospital, City Road, London EC1Y 2PD. LARGE CORNEAL GRAFfS CAN BE SUCCESSFUL 49 eral principles of corneal grafting but several junctiva which was sutured with 8/0 virgin points were of considerable importance. silk. Since many of the grafts were performed for (10) Where the indication for surgery perforations, particular care was taken in included active suppuration, specimens of all preparing the host bed. excised tissue were sent for microbiological examination. (1) The trephine size was chosen so that the entire wound edge was in healthy tissue, even Post-operatively, systemic steroids were when this meant the graft extending beyond not used routinely, but frequent application the limbus. of topical steroids was used, usually to begin (2) If, in the case of grafts extending beyond with Dexamethasone 0.1 % as frequently as the limbus, it was possible to preserve some every hour. The dosage was gradually limbal tissue, and perform either a sector reduced, but many patients received long­ keratoplasty or to place the graft slightly term therapy. Antibiotics appropriate to the eccentrically, this was done. condition were also used. (3) Having chosen the appropriate trephine In addition, any co-existent condition was size for the host, the host bed was gently treated as indicated, e.g. severe dry eye was marked but no attempt to cut host tissue with treated with frequent artificial tear drops and the trephine was made. This was done with if that was insufficient, by punctal occlusion. either a diamond blade or razor fragment In very large grafts, where a considerable free-hand using the trephine mark as a guide. amount of limbus had been excised, lid tap­ Excess pressure with trephine can distort the ing was employed when re-epithelialisation tissues excessively. was slow. Raised intraocular pressure was (4) The size of the host bed was carefully regarded as abnormal above 21 mmHg. measured (the cord length) and an approp­ Patients were seen at very frequent intervals riate donor size was chosen. Because of the during the first year after surgery and were low intraocular pressure of the host, there instructed to contact the hospital was often a disparity of 1 mm or more bet­ immediately if there were any evidence of ween the nominal trephine size used for host rejection. Rejection was diagnosed on the and donor, the donor by necessity being basis of a ciliary flush, the presence of flare larger. 8 Where possible a whole, moist and cells in the anterior chamber, in a previ­ chamber-stored eye was used as donor on the ously quiet eye, keratitic precipitates on the basis that it gave greater freedom in cutting donor endothelium, but not necessarily a an appropriate donor button. Khodadoust line. (5) Visco-elastic delamination of the \.lllderly­ ing tissue using healon or hydroxypropyl­ Results methyl cellulose 2% prevented damage to Seventeen grafts larger than 9.5 mm in the underlying structures and assisted diameter are reported, in 16 eyes of 15 gonioplasty in eyes which were perforated. patients. Included in this figure is one auto­ (6) Anterior cyclitic membranes were graft of 10 mm in diameter. Patients ages removed and posterior synechiae were bro­ ranged from 16 at the time of surgery to 74 ken but no attempt was made to remove the years, mean 47.9 years. Graft sizes ranged lens unless it was intumescent or subluxed. from 10 mm to 15 mm in diameter, median . (7) When the eyes were aphakic an interior 10.5, mean 11.3. (Fig. 1). Follow-up ranged vitrectomy was performed to prevent incarc­ from 8 months to 54 months, median 22 eration of gel, and to remOVe any inflammat­ months, mean 26.4 months. The indications ory or infected material. for keratoplasty and the nature of any under­ (8) Since all eyes in the series underwent lying relevant pathology are shown in Table keratoplasty a chaud, interrupted 10/0 nylon I. For those cases where there was suppura­ sutures were used. tion, the infecting organisms are shown in (9) Where there was bare sclera, whether Table II. In 3 cases despite rigorous host or donor, it was covered with host con- attempts, no organisms were identified. 50 c. M. KIRK NESS ET AL Table I CF, counts fingers; CSG, chronic simple glaucoma; HM, hand motion; HSK, herpes simplex keratitis; NPL, no perception of light; PBK, pseudophakic bullous keratopathy; Perf, perforation; SK suppurative keratitis The indications for keratoplasty Case no Diagnosis Precipitating Size Final event (host-mms) acuity 1. myopic SK, perf 11 6/24 (soft contact lenses) 2. Aphakia Iris prolapse 10.5 CF & SK, perf 3. Trauma Marginal 11 6/9 guttering & SK perf 4. Dysthyroid SK, perf 10 6/18 5. Rheumatoid Marginal 12 (sector) 6/9 arthritis guttering & SK perf 6. Rheumatoid Marginal 10 6/18 arthritis guttering, perf 7. Keratoconus Large, ectatic 10 6/6 cone 8. PBK SK/ 12 CF endophthalmitis perf 9. HSK SK, perf 10 6/9 10. HSK SK, perf 10.5 6/24 II. CSG SK/bleb 15 6/24 infection 12. Mooren's Perf 12 regrafted (14 in series) 13. Mooren's Perf 13 6/36 14. Mooren's Perf 14 6124 15. Cicatricial SK, perf 10.5 HM conjunctivitis 16 Aphakia Long-standing 10.5 NPL iris prolapse 17 HSK Angiosarcoma 10 (autograft) 6/6 LARGE CORNEAL GRAfTS CAN BE SUCCESSFUL 51 Table II The infecting organism in suppurative Visual acuity at final review, was 6/18 or cases. The case numbers are consistent with Table I better in 7 eyes, (41.3%) and less than 6/60 in 5 eyes, (29.4%) (Fig. 2.) In these latter cases Case no Infecting organism the poor vision was due to extensive myopic chorioretinal degeneration (1, no 2), cystoid 1 pseudomonas sp macular oedema (1, no 8), a new infective 2 Aspergillus terreus. 3 No organism identified episode (2, nos. 15,16) and graft oedema (1, 4 Moraxella no 11 - this patient is currently awaiting 5 Streptococcus pneumoniae, moraxella, Haemophillus influenzae, 100 staphylococcus epdermidis. 8 No organism identified 9 No organism identified 10 pseudomonas sp 11 Streptococcus pneumoniae 12 Staphylococcus aureus 5 5 10 20 30 40 50 ... 4 Time in months GI .a Fig. 3. The survival curve for all grafts plotted E ::J 3 according to the methods of Kaplan & Meier,9 i. e. Z the probability of graft survival is plotted against 2 time. npl • pi 0 hm • 10 10.5 11 12 13 14 15 ->- cf • • • "9 6/60 Size in mms C.I - ..- 10 -- --- --- - defined by -- Fig. I.