Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnos...Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnosed at a late age between January 2020 and October 2022 at the eye center of Abass Ndao Hospital. Complete ophthalmological examination was performed with eye imaging according to the cases. Results: 09 patients (10 eyes) were diagnosed with congenital optic disc abnormalities. The mean age was 29 years, with a sex ratio of 0.8. Three patients had consulted for unilateral decreased visual acuity since childhood, two for sudden vision loss and in four cases the diagnosis was fortuitous. Visual acuity was ranged from 1/200 to 20/20. Fundus examination showed myelinated retinal nerve fibers in four eyes, optic disc pit in three eyes including two complicated by maculopathy, two cases of morning glory syndrome and a case of pseudoduplication of the optic disc. Optical coherence tomography, ocular ultrasound B and OCT-Angiography were performed according to the cases. Conclusion: Congenital optic disc abnormalities are often diagnosed late. They are potentially amblyogenic and complications are not rare, worsening the visual prognosis. Their screening should be systematic by ophthalmological examination in newborns.展开更多
We present, to the authors＇ knowledge, the first reported case of an optic disc pit （ODP） and retinal cavernous hemangioma （RCH） in the same eye in addition to a review of both clinical entities. An ODP is a rare...We present, to the authors＇ knowledge, the first reported case of an optic disc pit （ODP） and retinal cavernous hemangioma （RCH） in the same eye in addition to a review of both clinical entities. An ODP is a rare congenital or acquired cavitary defect in the optic nerve head.展开更多
Applications of Atomic Force Microscopy (AFM) in optical disc technology are summarized. AFM is ideally suited to the characterization of nanometerscale pit and bump structures in CD/DVD manufacturing, so the relati...Applications of Atomic Force Microscopy (AFM) in optical disc technology are summarized. AFM is ideally suited to the characterization of nanometerscale pit and bump structures in CD/DVD manufacturing, so the relationship between production variables and pits/bumps geometry as well as relations between pits/bumps geometry and electrical performance of discs can be established to perform direct quality control of CD/DVD manufacturing. Applications of AFM in optical disc technology mainly fall into three parts: qualitative analysis of topography of discs/stampers, semiquantitative analysis of pits/bumps geometry of discs/stampers and length analysis of data marks on bump with statistics technology. Qualitative analysis of topography of discs/stampers and semiquantitative analysis of pits/bumps geometry of discs/stampers are chiefly oriented to the measurements of high error rate at beginning of play, pit morphology and block error rate, track pitch variations, pit depth monitoring as well as bump morphology and its surface roughness. It is discovered that the efficiency of the cooling channels of the mold has deteriorated, resulting in the discs being separated from the stamper while they are too soft due to inadequate cooling in the area where high error rate and block error rate are frequently produced. Length analysis of data marks with statistics technology is aimed at the analysis of track pitch and pitch variation, bump length (offset, deviation, asymmetry) and AFM jitter, bump width and width variation, bump height and height variation as well as side wall angle (slope) and slope variation. Statistical analysis of AFM images yields important information about optical disc microstructure and in turn provides information about the performance of the manufacturing process. It is very useful to analyze geometric parameters by considering the fundamental length groups of the data marks. The obtained results demonstrate that AFM have particular advantages in the quality control of discs/stampers manufacturing.展开更多
文摘Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnosed at a late age between January 2020 and October 2022 at the eye center of Abass Ndao Hospital. Complete ophthalmological examination was performed with eye imaging according to the cases. Results: 09 patients (10 eyes) were diagnosed with congenital optic disc abnormalities. The mean age was 29 years, with a sex ratio of 0.8. Three patients had consulted for unilateral decreased visual acuity since childhood, two for sudden vision loss and in four cases the diagnosis was fortuitous. Visual acuity was ranged from 1/200 to 20/20. Fundus examination showed myelinated retinal nerve fibers in four eyes, optic disc pit in three eyes including two complicated by maculopathy, two cases of morning glory syndrome and a case of pseudoduplication of the optic disc. Optical coherence tomography, ocular ultrasound B and OCT-Angiography were performed according to the cases. Conclusion: Congenital optic disc abnormalities are often diagnosed late. They are potentially amblyogenic and complications are not rare, worsening the visual prognosis. Their screening should be systematic by ophthalmological examination in newborns.
文摘We present, to the authors＇ knowledge, the first reported case of an optic disc pit （ODP） and retinal cavernous hemangioma （RCH） in the same eye in addition to a review of both clinical entities. An ODP is a rare congenital or acquired cavitary defect in the optic nerve head.
文摘Applications of Atomic Force Microscopy (AFM) in optical disc technology are summarized. AFM is ideally suited to the characterization of nanometerscale pit and bump structures in CD/DVD manufacturing, so the relationship between production variables and pits/bumps geometry as well as relations between pits/bumps geometry and electrical performance of discs can be established to perform direct quality control of CD/DVD manufacturing. Applications of AFM in optical disc technology mainly fall into three parts: qualitative analysis of topography of discs/stampers, semiquantitative analysis of pits/bumps geometry of discs/stampers and length analysis of data marks on bump with statistics technology. Qualitative analysis of topography of discs/stampers and semiquantitative analysis of pits/bumps geometry of discs/stampers are chiefly oriented to the measurements of high error rate at beginning of play, pit morphology and block error rate, track pitch variations, pit depth monitoring as well as bump morphology and its surface roughness. It is discovered that the efficiency of the cooling channels of the mold has deteriorated, resulting in the discs being separated from the stamper while they are too soft due to inadequate cooling in the area where high error rate and block error rate are frequently produced. Length analysis of data marks with statistics technology is aimed at the analysis of track pitch and pitch variation, bump length (offset, deviation, asymmetry) and AFM jitter, bump width and width variation, bump height and height variation as well as side wall angle (slope) and slope variation. Statistical analysis of AFM images yields important information about optical disc microstructure and in turn provides information about the performance of the manufacturing process. It is very useful to analyze geometric parameters by considering the fundamental length groups of the data marks. The obtained results demonstrate that AFM have particular advantages in the quality control of discs/stampers manufacturing.
