Biomedical subjects

S Priolo

Publications and source records attributed to S Priolo.

3 recordsLinked to original sources

PubMed2000

Effects of experimentally induced ametropia on the morphology and optical quality of the avian crystalline lens.

PURPOSE: To examine the effects of refractive error on avian lens morphology and optical quality. METHODS: Hatchling white leghorn chicks were unilaterally goggled for 7 days with either a form-deprivation goggle (n = 12), a -10 D defocus goggle (n = 12), or a +10 D defocus goggle (n = 12) to induce myopia and hyperopia. Optical quality of lenses (focal length and focal length variability) from treated and contralateral control eyes was assessed using a scanning laser apparatus. Lens morphology was examined by light and electron microscopy. RESULTS: Although the induction of refractive errors did not significantly alter lens size, shape, paraxial focal length, or average focal length, average focal length variability increased. Lenses from eyes goggled with form-deprivation and +10 D defocus goggles demonstrated a twofold increase in average focal length variability, when compared with their contralateral controls. The morphology of the lens is not altered by these experimental manipulations. CONCLUSIONS: This study provides evidence that the refractive development of the chick lens is not independent of the refractive development of the ocular globe and that chick lenticular development is influenced by both genetics and visual experience.

Animals↗

PubMed1999

Effect of age on the morphology and optical quality of the avian crystalline lens.

The effect of age on the avian lens was examined using White Leghorn chickens of five age groups: hatchling (n =19), 7 day (n = 15), 34 week (n =10), 2 year (n =24), and 5 year (n =25). The chick lens grows steadily up to 34 weeks of age, after which, the rate of growth slows down. During growth, average focal length of the lens becomes longer. However, no significant changes were noted between 2 and 5 year old lenses. An age related increase in average lenticular focal length variability (FLV) was observed, revealing that the optical quality of the lens decreases with age. Scanning electron microscopy demonstrated that: (1) the suture region of the lens becomes more diffuse and less precise with age; (2) the central regions of younger lenses are oblate spheroids, while older lenses become more apple-shaped; (3) individual lens fibres in the young lens are crescent-shaped, while older lens fibres are square-bracket-like in shape; (4) the edges of individual lens fibres become more jagged and irregular with age; and (5) the layering of lens fibres is more disorderly in older lenses, in contrast to the parallel and organized layering of fibres in young lenses.

Aging↗

PubMed1999

Relating clinical study design to basic research.

Devising any research study involves careful attention to its design, as well as the development of an appropriate research question and hypothesis. Together, these attributes ensure the validity of the study in question. In most clinical or epidemiological studies, the types of research designs are often explicitly noted, whereas in papers describing basic or biological research, they are couched in different terms or, more often, are ignored, thus potentially hindering communication between basic and clinical researchers. However, given that the framework for all valid scientific research is based on sound logic, it is proposed that for each study design, a direct homology exists between clinical and basic research paradigms, despite the problem of relating epidemiological vernacular to basic research. By applying examples of basic research protocols to traditional clinical study designs, this paper shows that parallels can be drawn between the two strategies, suggesting that in the absence of a conventional nomenclature to describe basic research study designs, the use of traditional clinical design jargon is valid in describing basic research protocols.

Case-Control Studies↗