Hydrodynamics of ageing Bruch's membrane: Implications for macular disease
ABSTRACT The hydrodynamic properties of isolated human Bruch's membrane and choroid were investigated as a function of age and retinal location. Macular and peripheral regions of the fundus showed an exponential decline of hydraulic conductivity with half-lives of 15 and 22 years respectively. Comparison of age profiles for hydraulic conductivity and lipid deposits suggests the involvement of two discrete processes for reduction in transport capability. The first appears to involve 'membrane remodelling' with a programmed decay rate leading to a major reduction in hydraulic conductivity by the fifth decade of life. The second commences in the fourth decade and is apparently dependent on the lipid content of Bruch's membrane.
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ABSTRACT: To describe the historical evolution of the role of lasers in effecting therapeutic changes in the four acellular membranes of the eye. Over the past 50 years, iterative developments have been instituted in lasers used for various forms of eye surgery predominately on the basis of data generated in early experiments in the 1960s to determine thresholds for damage and their incorporation in codes of practice for laser safety. The evolutionary steps are described. Excimer laser technology resulted in the generation of the new field of laser refractive surgery with over 40 million individuals now having undergone procedures such as photorefractive keratectomy and LASIK. Developments in lasers used for various forms of retinal surgery have undergone changes involving shorter and shorter pulse durations together with changes in beam energy distribution with implications for potential intervention in AMD prophylactically. Lasers have made a major impact on surgical treatment on all four acellular membranes of the eye but particularly Bowman's membrane in refractive surgery, where it has been demonstrated that it can be removed without significant consequences for eye health or vision.Eye (London, England) 01/2015; 29(1):46-64. DOI:10.1038/eye.2014.240 · 1.90 Impact Factor
Dataset: 671529 (2)
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ABSTRACT: Background. Recent clinical studies have shown that, in some degenerative retinal diseases, like age-related macular degeneration (AMD), the sensitivity of the rods decreases more rapidly than the sensitivity of the cones. The aim of this study was to evaluate if there is a correlation between the presence of hard drusen at the macular level and the rod damage responsible for the reduction in scotopic retinal sensitivity in subjects at risk for AMD. Methods. The authors selected 24 subjects (14 men and 10 women) with an average age of 67.25 ± 5.7 years. Macular hard drusen were present in 50% of the subjects at the fundus oculi exam.The researchers evaluated the retinal sensitivity to light in mesopic and scotopic conditions of each subject with an MP-1 scotopic microperimeter (MP-1S). Results. In subjects with hard drusen in the fundus oculi examination, there was a statistically significant reduction in scotopic retinal sensitivity, while the mesopic retinal sensitivity was not compromised. Conclusion. This study revealed how the presence of hard drusen at the macular level is associated with a reduction in scotopic retinal sensitivity compared to a control group of healthy subjects. Retinal functionality in a scotopic setting examined with MP-1S could be useful in early diagnosis of AMD.BioMed Research International 12/2014; 2014(671529):1-7. DOI:10.1155/2014/671529 · 2.71 Impact Factor