Factors influencing the suitability of organ-cultured corneas for transplantation. Invest Ophthalmol Vis Sci 38: 16

Purpose. To assess the influence of donor and storage factors on the suitability of organcultured corneas for penetrating keratoplasty (PKP) using multifactorial regression analysis. Methods. Corneas (mean donor age, 57 years; standard deviation, 21 years) were stored by organ culture at 34°C for up to 5 weeks (mean, 22 days; standard deviation, 6 days). The endothelium was assessed by light microscopy, and corneas with <2200 cells/mm 2 were considered unsuitable for PKP. Results. Of the 9250 corneas stored between 1992 and 1994, 59% were issued for PKP, 5% were discarded because of bacterial or fungal contamination, and 30% were unsuitable for PKP owing to endothelial deficiencies. Donor age had the strongest influence on suitability for PKP: >80% of corneas from donors younger than 40 years of age were issued for PKP compared with only 45% of corneas from donors 80 years of age and older. There was an overall decline in the percentage of corneas suitable for PKP with increasing storage time, but the rate of this decline was inversely related to donor age. Cause of death and post mortem times to enucleation and to storage had only a small influence on suitability for PKP. Conclusions. Criteria based on endothelial assessment rather than on donor age allow corneas from donors of all ages, stored by organ culture for extended periods, to be used for PKP. Organ culture also allows corneas with bacterial or fungal contamination to be identified and discarded before they are grafted. Invest Ophthalmol Vis Sci. 1997; 38:16-24

Age related changes in the non-collagenous components of the extracellular matrix of the human lamina cribrosa

AIMS To investigate age related alterations in the non-collagenous components of the human lamina cribrosa. METHODS Fibronectin, elastin, and glial fibrillary acidic protein (GFAP) staining were assessed in young and old laminae cribrosae. An age range (7 days to 96 years) of human laminae cribrosae were analysed for lipid content (n=9), cellularity (n=28), total sulphated glycosaminoglycans (n=28), elastin content (n=9), and water content (n=56), using chloroform-methanol extraction, fluorimetry, the dimethylmethylene blue assay, and ion exchange chromatography, respectively. RESULTS Qualitatively, an increase in elastin and a decrease in fibronectin and GFAP were demonstrated when young tissue was compared with the elderly. Biochemical analysis of the ageing human lamina cribrosa demonstrated that elastin content increased from 8% to 28% dry tissue weight, total sulphated glycosaminoglycans decreased, and lipid content decreased from 45% to 25%. There were no significant changes in total cellularity or water content. CONCLUSION These alterations in composition may be indicative of the metabolic state of the lamina cribrosa as it ages, and may contribute to changes in mechanical integrity. Such changes may be implicated in the susceptibility of the elderly lamina cribrosa and also its response to glaucomatous optic neuropathy

Adenovirus mediated gene delivery of tissue inhibitor of metalloproteinases-3 induces death in retinal pigment epithelial cells

Background: Sorsby's fundus dystrophy (SFD) and age related macular degeneration (ARMD) are retinal diseases associated with a high level of accumulation of mutant and wild type TIMP-3, respectively, in Bruch's membrane. The pathogenic role of TIMP-3 in these diseases is uncertain, but causative mutations have been identified in the TIMP-3 gene of patients with SFD. Recent reports that TIMP-3 causes apoptosis in certain cell types and not in others prompted the authors to investigate whether TIMP-3 causes apoptosis in cultured retinal pigment epithelium (RPE) cells. Methods: RPE and MCF-7 cells (as a positive control) were initially infected with replication deficient adenovirus, to overexpress β-galactosidase (RAdLacZ) or TIMP-3 (RAdTIMP-3). TIMP-3 was detected by western blotting and ELISA. Cell viability was defined by cell counts. ISEL was used to investigate the mechanism of cell death. Results: Cultured RPE cells produced small quantities of endogenous TIMP-3 and remained viable. However, overexpression of TIMP-3 caused a dose related death of RPE cells. The mechanism of cell death was apoptosis. Conclusion: The previously unreported finding of TIMP-3 induced apoptosis of RPE cells may account for some of the early features seen in SFD and ARMD

The Bristol shared care glaucoma study: outcome at follow up at 2 years

AIM—To examine the outcome of care for patients with glaucoma followed up by the hospital eye service compared with those followed up by community optometrists.
METHODS—A randomised study with patients allocated to follow up by the hospital eye service or community optometrists was carried out in the former county of Avon in south west England. 403 patients with established or suspected primary open angle glaucoma attending Bristol Eye Hospital and meeting defined inclusion and exclusion criteria were studied. The mean number of missed points on visual field testing in the better eye (using a "better/worse" eye analysis) in each group were measured. The visual field was measured using the Henson semiautomated central field analyser (CFA 3000). Measurements were made by the research team on all patients at baseline before randomisation and again 2 years after randomisation. The mean number of missed points on visual field testing in the worse eye, mean intraocular pressure (mm Hg), and cup disc ratio using a "better/worse" eye analysis in each group at 2 years were also measured. Measurements were made by the research team on all patients at baseline before randomisation and again 2 years after randomisation. An analysis of covariance comparing method of follow up taking into account baseline measurements of outcome variables was carried out. Additional control was considered for age, sex, diagnostic group (glaucoma suspect/established primary open angle glaucoma), and treatment (any/none).
RESULTS—From examination of patient notes, 2780 patients with established or suspected glaucoma were identified. Of these, 752 (27.1%) fulfilled the entry criteria. For hospital and community follow up group respectively, mean number of missed points on visual field testing at 2 year follow up for better eye was 7.9 points and 6.8 points; for the worse eye 20.2 points and 18.4 points. Similarly, intraocular pressure was 19.3 mm Hg and 19.3 mm Hg (better eye), and 19.1 mm Hg and 19.0 mm Hg (worse eye); cup disc ratio at 2 year follow up was 0.72 and 0.72 (better eye), and 0.74 and 0.74 for hospital and community follow up group respectively. No significant differences in any of the key visual variables were found between the two groups before or after adjusting for baseline values and age, sex, treatment, and type of glaucoma.
CONCLUSIONS—It is feasible to set and run shared care schemes for a proportion of patients with suspected and established glaucoma using community optometrists. After 2 years (a relatively short time in the life of a patient with glaucoma), there were no marked or statistically significant differences in outcome between patients followed up in the hospital eye service or by community optometrists. Decisions to implement such schemes need to be based on careful consideration of the costs of such schemes and local circumstances, including geographical access and the current organisation of glaucoma care within the hospital eye service.


Pulping processes project advisory committee meeting

"October 18-19, 1988."Copy 2 includes handouts.Fine structure of wood pulp fibers: project 3288 / R. H. Atalla ; Raman microprobe investigation of molecular structure and organization in the native state of woody tissue: project 3521-2 / R. H. Atalla ; The resolved Raman microprobe system / R. H. Atalla ; Smelt water explosions: project 3456-2 / T. M. Grace ; Energy conversion and scaling rules for steam explosions / T. M. Grace, N. T. Shiang, J. R. Hopenfeld ; Fundamental processes in alkali recovery furnaces: project 3473-1 / T.M. Grace ; Fundamental studies of black liquor combustion: project 3473-6 / T. M. Grace, A. Macek ; In-situ fume particle size and number density measurement from synthetic smelt: project 3473-6 / Jay C. L. Hsu, David T. Clay, Cary Presser ; Improved process for bleached pulp: project 3474 / T. J. McDonough ; Fundamentals of selectivity in pulping and bleaching: project 3475 / D. R. Dimmel ; Development and application of analytical techniques: project 3477 / D. B. Easty ; Fundamentals of brightness stability: project 3524 / U. P. Agarwal ; Strong, intact high yield fibers: project 3566 / T. J. McDonough, S. Aziz ; Computer model of recovery furnace: project 3605 / T. M. Grace -- Handout