Penetrating Keratoplasty (Corneal Transplantation) in Saudi Arabia
1984; King Faisal Specialist Hospital and Research Centre; Volume: 4; Issue: 3 Linguagem: Inglês
10.5144/0256-4947.1984.235
ISSN0975-4466
AutoresDavid J. Paton, Khalid F. Tabbara, Eduardo Pinheiro Penna,
Tópico(s)Intraocular Surgery and Lenses
ResumoOriginal ArticlesPenetrating Keratoplasty (Corneal Transplantation) in Saudi Arabia David Paton, MD Khalid Tabbara, and MD Eduardo PennaMD David Paton Medical Director, King Khaled Eye Specialist Hospital, P.O. Box 7191, Riyadh 11462, Saudi Arabia Search for more papers by this author , Khalid Tabbara Director of Research, Chief of Cornea and External Disease, King Khaled Eye Specialist Hospital, P.O. Box 7191, Riyadh 11462, Saudi Arabia Search for more papers by this author , and Eduardo Penna Fellow, Cornea and External Disease, King Khaled Eye Specialist Hospital, P.O. Box 7191, Riyadh 11462, Saudi Arabia Search for more papers by this author Published Online:1 Jul 1984https://doi.org/10.5144/0256-4947.1984.235SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutABSTRACTABSTRACTUsing donor corneas from the United States and Sri Lanka, surgeons performed 115 penetrating keratoplasties at King Khaled Eye Specialist Hospital during its first 8 months of operation. To assess the program, 78 of these patients, who had a postoperative follow-up of 2 months or more, were studied. These patients were often blind, presented with severe corneal pathology and other ocular complications, and were selected for surgery according to need rather than favorable prognosis. At follow-up, 56 (83%) had a clear graft, 5 (6%) had a partially clear graft, and 8 (10%) had graft failure. All patients received topical steroids and antibiotics following surgery. Complications included dry eye syndrome, due both to cicatrization from trachoma and to dry weather in Saudi Arabia, which added to the risk of secondary infection and sometimes led to persistent epithelial defects. Findings suggest that heavy corneal vascularization may increase the incidence of corneal graft rejection. The high percentage of graft clarity indicates that the eye banking method and keratoplasty techniques used are appropriate.INTRODUCTIONCorneal diseases leading to blindness are common in Saudi Arabia. Badr and Qureshi1 showed that corneal infection was responsible for blindness among 69% of students attending schools for the blind in the Eastern Province of Saudi Arabia. The majority of corneal infections are preventable. Visual impairment secondary to corneal infections and other causes of corneal opacification may be treated by penetrating keratoplasty (corneal transplantation). Many problems, however, face the surgeon who attempts such procedures in Saudi Arabia.A major challenge is obtaining viable donor corneal tissues. Although none of the major religions of the world opposes the concept of grafting corneas from a cadaver, there is no country in which eye banking has become established easily or rapidly. Public education through the media and by other means and layman participation are essential in the development of eye banking. The public everywhere must come to realize that giving a cornea is comparable to taking a fingernail; yet such a simple procedure can help to restore sight to many blind patients. Until this concept is fully appreciated, ophthalmologists in Saudi Arabia must depend upon donor tissue shipped from abroad in McCarey-Kaufman (M-K) medium.2 The donor cornea with a rim of sclera is excised using sterile technique and is placed in sterile M-K medium. It is then shipped at 4 °C to an often remote hospital awaiting its arrival.At the King Khaled Eye Specialist Hospital, we have dealt successfully with most of the obstacles that confront the corneal transplant surgeon. Over the period of this hospital’s first 8 months of operation, a total of 115 penetrating keratoplasties have been performed. Most of the donor corneas were obtained from the United States, and a few have been received from Sri Lanka. The study reported constitutes a preliminary assessment of corneal transplantation as performed to date at the King Khaled Eye Specialist Hospital (KKESH).PATIENTS AND METHODSPatientsA total of 115 penetrating keratoplasties were performed during the period of 1 March to 15 October 1983. All patients were referred to the Cornea Service of the King Khaled Eye Specialist Hospital because of their corneal problems. Priority was given to blind patients. Only patients with a postoperative follow-up of 2 months or more were included in this retrospective study.Keratoplasty TechniqueThe surgical techniques employed by the eight surgeons performing these operations were quite similar. The size of the graft was usually determined at the time of surgery, and the trephine selected for the host eye was always between 6.5 mm and 8.0 mm in diameter. The donor button was prepared from corneal tissue by placing the corneal endothelium facing upwards on a cutting block. A trephine was applied from the endothelial surface with uniform pressure to penetrate through to the epithelial surface. The button was set aside, endothelium up, in a moist sterile chamber and covered with M-K medium. The patient’s diseased corneal tissue was marked with a trephine of appropriate size with the blade pressed against the eye and rotated in a uniform manner to partially penetrate the cornea. The anterior chamber was entered by cutting with a super-blade and the diseased corneal tissue was excised using scissors.Some patients had cataract extraction combined with the penetrating keratoplasty. In certain instances posterior chamber intraocular lens implantation was done at the time of the cornea operation.The donor button was then placed in the recipient corneal bed, and in most cases the graft was sutured in place with a continuous 10-0 monofilament nylon suture (Fig. 1). The corneal graft had the same or slightly larger diameter (up to 0.5 mm larger) than that of the recipient corneal bed. Therapeutic soft contact lenses were not used routinely after surgery. In certain instances, however, soft contact lenses were used in patients who had postoperative epithelial effects of the grafts. Tear film insufficiency as a result of trachoma is a common and important observation in patients requiring keratoplasty.Fig. 1. An eye with severe postinflammatory corneal blindness is shown before and after penetrating keratoplasty. The donor tissue constitutes a graft of 7.5 mm in diameter and is secured by a single continuous No. 10-0 monofilament nylon suture.Download FigurePostoperative Follow-upAll patients were placed on topical corticosteroids and antibiotics following surgery. Most patients were kept in the hospital for 1 week and followed in the KKESH outpatient clinic at weekly intervals for 3 weeks, followed by periodic check-ups at 2 to 4 weeks thereafter.RESULTSAge and Sex DistributionTable 1 shows the age and sex distribution of the patients in the study. There were 48 male and 30 female patients. Sixty-nine percent of the 78 recipients were over the age of 50 years. No patients were under age 10. The patients were randomly selected among referral cases; generally the patients with most visual need were offered surgery—not those patients with the better prognosis.Table 1. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: age and sex distributionTable 1. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: age and sex distributionIndications for KeratoplastyTable 2 lists the indications for penetrating keratoplasty among the 78 patients in the study. Fifty-six (71%) had postinfectious corneal scars. One third of this group had anterior adherent leukomata from previous corneal perforation. None of the patients had evidence of herpetic keratitis. The causes of the corneal infections included bacterial corneal ulcers, trachoma, and smallpox. Corneal dystrophy was observed in seven (9%) of the patients. Keratoconus, bullous keratopathy, Labrador keratopathy, and post-traumatic corneal scarring were less frequently encountered (Fig. 2).Table 2. Indications for penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983Table 2. Indications for penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983Fig. 2. A post-traumatic vascularized corneal scar is shown in the photograph on the left. The right photograph shows the same eye after penetrating keratoplasty. Often such surgery requires additional steps during the operative procedure for lysis of iris adhesions, removal of a traumatic cataract, excision of membranes, and sometimes vitrectomy.Download FigureTable 3 deals with preoperative corneal vascularization. At least 62% of the patients had noteworthy corneal vascularization prior to surgery. Table 4 demonstrates the secondary diagnoses. Evidence of trachoma was observed in 48 (62%) of the 78 patients.Table 3. Penetrating keratoplasty at King Khaled Eye Specialist Hospital 1983: preoperative corneal vascularizationTable 3. Penetrating keratoplasty at King Khaled Eye Specialist Hospital 1983: preoperative corneal vascularizationTable 4. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: secondary diagnosisTable 4. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: secondary diagnosisPenetrating keratoplasty combined with cataract extraction was performed in 33 (42%) of the 78 patients. The high preponderance of cataracts among this group is readily explicable in that 54 (69%) of the 78 recipients were over age 50. Twenty patients had extracapsular cataract extraction, and 13 patients had intracapsular cataract extraction combined with the penetrating keratoplasty.Type of SuturingSeventy-one percent of the patients had continuous 10-0 monofilament nylon suture used for their corneal grafts; only 7 (9%) patients had interrupted nylon sutures.Outcome of KeratoplastyTable 5 depicts the clarity of the graft at 2 or more months following surgery. Sixty-five (83%) patients had clear grafts while 8 patients (10%) had graft failure. The failures were mostly due to allograft reaction, related principally to the high prevalence of preoperative corneal vascularization. Fig. 3 demonstrates the category of visual impairment before and 2 or more months after penetrating keratoplasty.3Table 5. Penetrating keratoplasty at King Khaled Eye Specialist Hospital 1983: clarity of graftTable 5. Penetrating keratoplasty at King Khaled Eye Specialist Hospital 1983: clarity of graftFig. 3. Pre- and postoperative category of visual acuity. Categories 1 and 2, 20/70 to 20/400: category 3, counting fingers (CF) at 3m to CF at 1 m; category 4, CF at 1 m to light perception; category 5, no light perception.Download FigureComplicationsThere were no serious intraoperative complications. Postoperative complications, as shown in Table 6, included persistent postoperative epithelial defects in 13 (17%) patients. Wound dehiscence occurred in 3 patients; one of these patients had a loose suture. Postoperative bacterial corneal ulcers were seen in five patients and occurred after the patients were discharged from the hospital. Pseudomonas species, Streptococcus pneumoniae, and Staphylococcus aureus and S. epi-dermidis were the organisms encountered. Table 7 lists the causes of poor visual outcome in patients with clear grafts. Optic atrophy from a variety of causes was the leading culprit in 6 (8%) patients. Chorioretinal degeneration was observed in 3 (4%) patients. Preoperative evaluation by A- and B-scan ultrasonography is the best diagnostic modality that can be employed when corneal opacification and cataract prevent visualization of the fundus, but such diagnostic procedures do not detect chorioretinal degeneration, optic atrophy, or macular disease.Table 6. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: complicationsTable 6. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: complicationsTable 7. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: causes of poor visual outcome with clear graftTable 7. Penetrating keratoplasty at King Khaled Eye Specialist Hospital in 1983: causes of poor visual outcome with clear graftDISCUSSIONThe success of penetrating keratoplasty depends on a number of factors: the severity of the corneal disease, corneal vascularization, corneal thickness, intraocular pressure, aphakia, tear-film, and lid function.4 The surgical technique is of considerable importance. In addition, the postoperative follow-up and patient compliance are mandatory for success in keratoplasty. The cases selected in this group generally represent patients with severe corneal pathology associated with other ocular complications at the time of surgery; patient selection was not based upon favorable prognosis but upon visual need as first priority.The technique of keratoplasty employed at KKESH and the “eye banking” method summarized appear to be appropriate and yield a high incidence of success as demonstrated by the clarity of the grafts, reflecting good viability of the donor endothelium. Approximately two thirds of the patients in this study had evidence of trachoma, which causes conjunctival scarring leading to mucous deficiency and instability in the tear film. Furthermore, cicatrization from trachoma may obliterate lacrimal ductules, causing aqueous deficiency and dry eye syndrome. These factors, in addition to the weather conditions of Saudi Arabia, contribute to the instability of the tear film and dryness of the corneal epithelial cells, leading to persistent epithelial defects and an added risk of secondary infections. Such factors may certainly influence the survival of the graft and may compromise the visual outcome. It is highly recommended that these patients use artificial tears on a long-term basis following surgery.Furthermore, the presence of corneal vascularization (especially deep blood vessels) may increase the incidence of corneal graft rejection.5–7 In the group studied, approximately 62% of the patients had evidence of corneal vascularization before surgery. Such patients must be followed closely and should be maintained on topical corticosteroid therapy to suppress the immunologic response to the donor corneal tissue. One may have to risk reactivating trachoma by prolonged steriod therapy to prevent or control an allograft reaction. In many of our patients, we had to administer simultaneous antimicrobial therapy for trachoma, consisting of systemic doxycycline 100 mg orally twice daily and topical tetracycline 1% ointment applied twice daily. The two patients who developed endophthalmitis following penetrating keratoplasty were the recipients of infected donor tissue received from Sri Lanka in M-K medium that did not contain antibiotics; this fact was unknown to the surgeons at the time of surgery. The bacteria that were recovered from the infected eyes were the same bacteria cultured from the donor tissue.The preliminary results of this study have prompted us to pursue a larger series, with even further emphasis on patient education to assure compliance and achieve adequate postoperative care. Despite the difficulties that we face in the postoperative care of patients undergoing keratoplasty, we strongly believe that the facilities offered at KKESH and the support of many physicians who have referred their patients to our facility make the environment for this surgical procedure quite favorable, as documented in this preliminary report.Authors’ note: Since this preliminary report was written, an additional 127 keratoplasties have been performed at KKESH. The results, in general, remain very encouraging as to the future of corneal transplant surgery in Saudi Arabia with the techniques reported here.ARTICLE REFERENCES:1. Badr IA, Qureshi IH: "Cause of blindness in the Eastern Province blind schools" . Saudi Medical Journal 4(4): 331–411983. Google Scholar2. McCarey BE, Kaufman HE: "Improved corneal storage" . Invest Ophthalmol 13:165–731974. Google Scholar3. International Classification of Disease. 9th Revision. Geneva, World Health Organization, 1978. Google Scholar4. Paton D: "The prognosis of penetrating keratoplasty based upon corneal morphology" . Ophthalmic Surg 7(3):36–451976. Google Scholar5. Paton D: "The principal problems of penetrating keratoplasty" ., in: Symposium on Medical and Surgical Diseases: Transactions of Ophthalmology. St Louis, CV Mosby Company, 1980. Google Scholar6. Stark WJ: "Transplantation immunology of penetrating keratoplasty" . Trans Am Ophthalmol Soc 78:1079–1171980. Google Scholar7. Aldredge OC, Krachmer JH: "Clinical types of corneal transplant rejection: their manifestations, frequency, preoperative correlates, and treatment" . Arch Ophthalmol 99(4):599–6041981. Google Scholar Previous article Next article FiguresReferencesRelatedDetails Volume 4, Issue 3July 1984 Metrics History Published online1 July 1984 KeywordsCorneaCorneal diseasesACKNOWLEDGEMENTSWe would like to acknowledge the help of Najwa Tabbara, Monzer Jabak, and Donna Harclerode.InformationCopyright © 1984, Annals of Saudi MedicinePDF download
Referência(s)