PubMed · 16340558
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
Vasumathy Vedantham. 2005. Correspondence.. https://doi.org/10.1097/00006982-200512000-00035
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
AIM: To determine the temporal retinal vessel angle in babies and its relation to preterm birth. METHODS: Digital images were obtained during routine screening for retinopathy of prematurity (ROP). The temporal retinal vessel angle was measured in 164 eyes of 82 babies born "very preterm" (24-27 weeks gestational age (GA)), "preterm" (28-31 weeks GA), and "near term" (>/=32 weeks GA). RESULTS: Mean temporal vessel angle (TVA) for all three GA groups together is 80.0 degrees (SD 17.0 degrees ) for the right eye and 80.5 degrees (16.7 degrees ) for the left eye. The range is right eye 59-106 degrees , left eye 69-97 degrees , with 95% data above 67 degrees for the right and 63 degrees for the left eye. For babies born near term, TVA is 82 degrees in each eye. There is a high degree of interocular symmetry between right and left eyes and a statistically insignificant trend for increasing TVA with increasing GA. The presence and stage of ROP affected one parameter of the left eye alone. CONCLUSIONS: These data provide normative data on the TVA in babies and will facilitate, especially if there is interocular asymmetry, determining whether there is macular displacement.
Myopic foveoschisis (MF) can now be recognized as the result of recent progress in imaging diagnostic technology such as optical coherence tomography (OCT). MF predominantly occurs in highly myopic eyes with posterior staphyloma, and often induces visual loss and/or metamorphopsia. In order to better understand the detailed pathogenesis of MF, we observed 21 myopic eyes after vitrectomy using OCT. Retinal microfolds along the retinal vessels were observed in over 60% of the patients 6 months after surgery. Relative inflexibility of retinal arterioles/venules may be one of the causes for MF. We performed a pilot study (6 eyes of 5 patients) to treat MF by vitrectomy including vitreous cortex removal, internal limiting membrane peeling, and gas tamponade. In all 6 eyes the fovea was reattached and vision improved by more than two lines. This pilot study indicates that vitrectomy is an effective and safe treatment for MF.
Macular degeneration (MD), the leading cause of visual impairment in the developed world, damages the central retina, often obliterating foveal vision and severely disrupting everyday tasks such as reading, driving, and face recognition. In such cases, the macular damage eliminates the normal retinal input to a large region of visual cortex, comprising tens of square centimeters of surface area in each hemisphere, which is normally responsive only to foveal stimuli. Using functional magnetic resonance imaging, we asked whether this deprived cortex simply becomes inactive in subjects with MD, or whether it takes on new functional properties. In two adult MD subjects with extensive bilateral central retinal lesions, we found that parts of visual cortex (including primary visual cortex) that normally respond only to central visual stimuli are strongly activated by peripheral stimuli. Such activation was not observed (1) with visual stimuli presented to the position of the former fovea and (2) in control subjects with visual stimuli presented to corresponding parts of peripheral retina. These results demonstrate large-scale reorganization of visual processing in MD and will likely prove important in any effort to develop new strategies for rehabilitation of MD subjects.