Changing Trends in Corneal Transplantation in Aotearoa/New Zealand, 1991 to 2020: Effects of Population Growth, Cataract Surgery, Endothelial Keratoplasty, and Corneal Cross-Linking for Keratoconus.

PURPOSE: The purpose of this study was to identify trends in the primary indication for keratoplasty in New Zealand/Aotearoa (NZ) after significant population growth, increase in the number of cataract surgeries per population, widespread adoption of endothelial keratoplasty, and introduction of corneal cross-linking for keratoconus. METHODS: Statistical analysis of the New Zealand National Eye Bank's prospective database of all keratoplasties was performed between January 1991 and January 2020. Indications for keratoplasty were isolated for the primary diagnosis. RESULTS: In total, 6840 corneas were transplanted with mean 236 ± 57.5 transplants/year, increasing from 2.55 to 6.06 per 100,000 NZ population/year. Over the past decade, the number of transplant recipients aged 60 years or older has increased and recipients aged 20 to 39 years have plateaued. In 2019, for the first time, regraft became the most common indication (30.9%), followed by keratoconus (27.9%) and corneal dystrophy (18.8%), with a steady decline in bullous keratopathy. Proportions of the keratoplasty technique changed dramatically: penetrating keratoplasty fell from 91.4% in 2006 to 55.0% in 2019, Descemet's stripping endothelial keratoplasty increased from 0% to 29.5%, anterior lamellar keratoplasty increased from 2.5% to 5.7%, and Descemet membrane endothelial keratoplasty increased from 0% to 9.1%. CONCLUSIONS: Keratoplasty trends in Aotearoa/NZ have changed considerably because of the evolution of phacoemulsification and keratoplasty techniques. Unlike proportions observed overseas, NZ still performs penetrating keratoplasties in over half of all transplants. Corneal cross-linking may be having an early effect of reducing keratoplasty rates for keratoconus.

New Zealand trends in corneal transplantation over the 25†years 1991-2015.

AIMS: To report the 25-year longitudinal trends in indications and corneal transplantation techniques in New Zealand. METHODS: Statistical analysis of prospectively acquired New Zealand National Eye Bank (NZNEB) electronic database from 1991 to 2015 inclusive. Subjects were recipients of corneal transplants in 62 centres supplied by the NZNEB. Main outcome measures were indications, recipient age and transplantation techniques. RESULTS: From January 1991 to December 2015, NZNEB supplied tissue for 5574 corneal transplants, increasing annually from 89 (1991) to 290 (2015). Penetrating keratoplasty remained the most commonly performed technique throughout the 25-year period, although it decreased from 98.9% of all transplants in 1991 to 60.3% in 2015. There was a corresponding increase in deep anterior lamellar and endothelial keratoplasty over the most recent decade from 2.5% to 7.2% and 4.9% to 31.4%, respectively. Keratoconus remained the leading indication for keratoplasty through to 2015 (34.5%). Regrafts (23.1%) and Fuchs endothelial corneal dystrophy (17.0%) have become more common indications, while bullous keratopathy has become less common (10.8%). There was a bimodal distribution in age with peaks at 20-29 and 60-79 years. There was a reduction in recipients under age 40 and corresponding increase in the percentage of recipients aged 40-69. CONCLUSION: Changing indications and increasing uptake of lamellar keratoplasty have been significant international trends over the last 25 years. However, New Zealand's corneal disease and population characteristics create unique longitudinal trends, with keratoconus remaining the leading indication and penetrating keratoplasty the leading technique from 1991 to 2015.

Standard terminology and labeling of ocular tissue for transplantation.

PURPOSE: To develop an internationally agreed terminology for describing ocular tissue grafts to improve the accuracy and reliability of information transfer, to enhance tissue traceability, and to facilitate the gathering of comparative global activity data, including denominator data for use in biovigilance analyses. METHODS: ICCBBA, the international standards organization for terminology, coding, and labeling of blood, cells, and tissues, approached the major Eye Bank Associations to form an expert advisory group. The group met by regular conference calls to develop a standard terminology, which was released for public consultation and amended accordingly. RESULTS: The terminology uses broad definitions (Classes) with modifying characteristics (Attributes) to define each ocular tissue product. The terminology may be used within the ISBT 128 system to label tissue products with standardized bar codes enabling the electronic capture of critical data in the collection, processing, and distribution of tissues. Guidance on coding and labeling has also been developed. CONCLUSIONS: The development of a standard terminology for ocular tissue marks an important step for improving traceability and reducing the risk of mistakes due to transcription errors. ISBT 128 computer codes have been assigned and may now be used to label ocular tissues. Eye banks are encouraged to adopt this standard terminology and move toward full implementation of ISBT 128 nomenclature, coding, and labeling.

The New Zealand National Eye Bank study: trends in the acquisition and storage of corneal tissue over the decade 2000 to 2009.

PURPOSE: To evaluate trends in the acquisition, storage, and utilization of donated corneal tissue in New Zealand, 2000 to 2009. METHODS: The New Zealand National Eye Bank records were analyzed for the decade January 2000 to December 2009. Variables analyzed included donor demographics (age, sex, and ethnicity), donor source, donor cause of death, death-to-preservation interval (DPI), corneal storage time, tissue contamination, endothelial assessment, cornea suitability for transplantation, and corneal tissue utilization. RESULTS: A total of 1268 eye donors were identified during the 10-year period. Overall, 36% (n = 457) were female and 64% male (n = 813). Median donor age was 67 years, and 23% of donors were younger than 50 years (range, 5-90 years). There was a decrease in donor age over the decade (P = 0.006). The median DPI was 18.5 hours. No relationship was identified between cornea suitability for transplantation and DPI (P = 0.28) or donor gender (P = 0.54). There was a low microbial contamination rate (1%). Human immunodeficiency virus, hepatitis B, or hepatitis C serology was positive in 48 donors (4%). Overall, 90% of corneas were suitable for transplantation with a high utilization rate (88%). A novel association was identified between male sex and lower corneal endothelial cell density (P = 0.03). CONCLUSIONS: This New Zealand National Eye Bank analysis identified trends in the acquisition, storage, and utilization of donated corneal tissue throughout New Zealand over the past decade and provides valuable additional information to the international eye bank data.

Trends in the distribution of donor corneal tissue and indications for corneal transplantation: the New Zealand National Eye Bank Study 2000-2009.

BACKGROUND: To investigate the indications for corneal transplantation and the distribution of donor corneal tissue in New Zealand. DESIGN: Analysis of the prospective database of the New Zealand National Eye Bank. PARTICIPANTS: A total of 2205 corneal transplants were assessed. METHODS: New Zealand National Eye Bank records were analysed for the decade 2000-2009. MAIN OUTCOME MEASURES: Variables analysed included donor corneal tissue distribution (including public and private sectors), indications for transplantation, donor corneal tissue recipient demographics (age and gender) and corneal transplantation type. RESULTS: An average of 220 corneal transplants were performed each year over the 10-year period (n=2205). The median recipient age was 45years (range 3 to 102years) and 54.0% of recipients were male. In total 71.8% of transplants were performed in the public health sector. Surgeons in the Auckland metropolitan area performed 47.2% of all corneal transplants. The most common indications for corneal transplantation were: keratoconus (41.1%), repeat transplant (17.0%), aphakic/pseudophakic bullous keratopathy (13.9%), corneal dystrophy (10.7%), keratitis (7.9%) and trauma (3.7%). Overall, penetrating keratoplasty accounted for 90.7% of all corneal transplants, however, during the latter half of the study there was a progressive shift in transplantation type, with deep anterior lamellar keratoplasty and Descemet's stripping endothelial keratoplasty combined accounting for 32.3% of all transplants in the final year of the study period. CONCLUSIONS: This New Zealand National Eye Bank study provides valuable data regarding the indications for corneal transplantation, transplant recipient demographics and changes in transplantation type in New Zealand over the past decade.

The New Zealand National Eye Bank: survival and visual outcome 1 year after penetrating keratoplasty.

PURPOSE: To identify potential donor, recipient, surgical, and postoperative factors that may influence survival and visual outcome of penetrating keratoplasty (PKP). METHODS: As part of a prospective longitudinal study, the electronic records of the New Zealand National Eye Bank were analyzed for the 10-year period from 1994-2003. Both univariate and multivariate analysis was performed. RESULTS: During the study period, the New Zealand National Eye Bank supplied 1820 corneas for PKP and 1629 (90%) had 1-year follow-up data. Overall, the 1-year survival rate was 87% (n = 1429). Donor factors including age, donor source, cause of death, death-to-preservation interval, endothelial cell density, donor lens status, and storage duration, were not significantly associated with decreased survival. The leading cause of PKP failure was irreversible rejection (7%, n = 114). Independent risk factors identified for decreased PKP survival were: 1 or more episodes of reversible rejection, active inflammation at PKP, preexisting corneal vascularization, intraoperative complications, small graft size (≤ 7.25 mm), large graft size (≥ 8.5 mm), preoperative glaucoma, and a preoperative diagnosis of regraft or trauma. A best-corrected Snellen visual acuity of 6/12 or better was achieved in 60% of eyes [mean: 6/15 (logarithm of the minimum angle of resolution 0.40)]. Keratoconus and Fuchs endothelial dystrophy were the diagnoses with best survival and visual outcome, whereas, bullous keratopathy, trauma or noninfective keratitis were associated with poorer visual outcome. CONCLUSIONS: Several independent risk factors were identified that significantly influenced PKP first year survival outcome. This information is valuable to patients and surgeons with respect to determining prognosis and clinical decision making.

Centennial review of corneal transplantation.

Abstract One hundred years ago, on 7 December 1905, Dr Eduard Zirm performed the world's first successful human corneal transplant. This significant milestone was achieved only after many decades of unsuccessful trial and error; however, it did not lead to relatively 'routine' keratoplasty success for several more decades. The idea of replacing an opaque cornea had been suggested for centuries, and had stimulated theoretical approaches to the problem by many esteemed physicians throughout history. However, little practical progress was made in the ultimate realization of the dream until the 19th century when pioneering surgeons pursued extensive studies in relation to both animal and human 'keratoplasty'. Clinical progress and scientific insight developed slowly, and it was ultimately due to parallel advances in medicine such as anaesthesia and antisepsis that Zirm's success was finally achieved. Key concepts were enshrined such as the use of fresh tissue from the same species, careful placement and handling of tissue, and the development of specialized instrumentation such as the circular trephine. In the latter half of the 20th century, many 'masters' of corneal surgery evolved significant refinements in technique and instrumentation with the development of corticosteroids, antibiotics, surgical microscopes, improved trephines, viscoelastics and suture materials, that enable this delicate procedure to be routinely performed with the prospect of success. There are still limitations to corneal transplantation, and corneal allograft rejection still poses the greatest challenge to the modern corneal surgeon. In the foreseeable future it may be in the laboratory, rather than the theatre, that further milestones will be achieved. This review aims to highlight the significant milestones in the rich history of corneal transplantation, and to pay tribute to the many inspired and dedicated individuals involved in the development of keratoplasty to a point where the procedure is now a standard tool in the repertoire of ophthalmic surgery and more than a million people have enjoyed restoration of useful sight.