A National Consensus Forum on improving cornea donation and transplantation access in Canada

A consensus meeting was held in Toronto on February 9–10, 2020 to discuss ways to improve cornea donation and transplantation access in Canada. The meeting brought together eye and tissue bank representatives, health authority and hospital leadership, transplant ophthalmologists, organ donation organizations, transplant recipients, donor families and several national organizations. Through facilitated discussions in multidisciplinary, gender-balanced, and geographically balanced small groups, participants identified opportunities for improvement in the Canadian cornea donation and transplantation system. Discussion occurred around broad themes of donor tissue demand, supply, access, utilization, interprovincial sharing and cost recovery, interprovincial knowledge sharing and research. This event marked the first time in 10 years in which the Canadian cornea transplantation community came together.

Molecular Genetics of Keratoconus: Clinical Implications

Occurrence of keratoconus is pan-ethnic with reported prevalence ranging widely from 1:400 to about 1:8000, higher in Asian than Western populations. Its genetics is complex with undefined pattern of inheritance. Familial traits are also known. More than 50 gene loci and 200 variants are associated with keratoconus, some through association studies with quantitative traits of cornea features including curvature and central thickness. Environmental, behavioral, and epigenetic factors are also involved in the etiology, likely interactively with genetic susceptibility. Regardless of sex and age of disease onset, clinical courses and responses to treatment vary. Keratoconus is a major cause of cornea transplantation and is potentially blinding. Currently collagen cross-linking provides effective treatment although responses from some patients can be unpredictable with complications. Early diagnosis is vital to obtain good treatment outcome, but in many patients early signs and symptoms are not obvious. While there are potential biomarkers, reliable pre-symptomatic detection and prediction of treatment response may require multitude of gene variants, cornea properties, and external risk factors.

Collagen-Chitosan- Glycerol-HPMC Composite as Cornea Artificial Candidate

The number of blindness is tend to be increased year by year. One of the blindness cause is cornea ulcer.The cause of cornea ulcer is bacteria, fungi, and herpes simplex virus. Cornea transplantation is the only treatment which could widely accepted for blindness. Transplant by donor network becomes the only treatment that is acceptable on a large for blindness. However, treatment donor transplants have many shortcomings in complications post surgery such as host response, donor limitations, incompatibility and the length of time healing. As technology develops, there are many corneal substitutes based on natural ingredients derived from collagen or their derivatives because they promise better properties in biocompatibility. The aim of research are to conduct the synthesis and characterization of collagen- chitosan- glycerol - HPMC as artificial cornea such functional cluster test, cytotoxycity test, morphological test and antibacterial test. Based on functional cluster test, there are functional groups of all components of composite materials. While from cytotoxicity test, all samples have a percentage of living cells above 85%. The morphology test is showed that the pore size of sample B with composition collagen-chitosan-glycerol-HPMC is in accordance with the standard pore size for keratoprothesis. Sample A (collagen-chitosan-glycerol) and sample B (collagen-chitosan-glycerol-HPMC) have strong antibacterial properties.Biocomposite of collagen-chitosan-glycerol could be considered as artificial cornea due to the proximity with the corneal characteristics.

THE PARTIAL TRANSPLANTATION OF DESCEMET’S MEMBRANE WITH ENDOTHELIUM (½ AND ¼ DMEK)

The lamellar keratoplasty is the first operation of choice under selective pathology of cornea. In view of satisfactory results of endothelium surgery similar operations are implemented at more earlier stages that increases need in donor tissue. The life-span of population increases hence number of patients in need of cornea transplantation also increases and number of intact cadaver corneas decreases because of stable increasing of number of surgical interventions at the frontal section of eye. The purpose of study is to analyze operations of partial transplantation of Descemet's membrane with endothelium (½ DMEK and ¼ DMEK). Material and methods. The analysis was applied to the results of 10 operations ½ DMEK (semi-DMEK, hemi-DMEK) and 10 operations ¼ DMEK, implemented at eyes of 20 patients with primary endothelium dystrophy. The average age of patients made up to 64,9±10,4 years. The average visual acuity prior to implementation of partial DMEK amounted to 0,14 ± 0,08, average central thickness of cornea, according data of optical coherent tomography, made up to 669 ± 91 мкм. Results. In 16 out of 20 cases of partial DMEK, restoration of transparency of cornea, resorption of edema and increasing of visual acuity was achieved. In other 4 cases, during one week after partial DMEK, a subtotal DMEK was implemented. In 16 cases, average visual acuity increased up to 0,8 ± 0,3 three months later after operation. Conclusion. The techniques of partial transplantation of Descemet's membrane with endothelium (¼ DMEK и ½ DMEK) are efficient for treatment of primary endothelium pathology of cornea and permit to apply donor's material as much as possible rationally.