Purchase this article with an account.
Wendy S. Chen, Thomas R. Friberg, Andrew W. Eller, Carlos Medina; Advances in Retinal Imaging of Eyes with Hazy Media: Further Studies. Invest. Ophthalmol. Vis. Sci. 2011;52(14):4036.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
In eyes with media opacities, dense cataracts, corneal edema, small pupils, or vitreous opacities, biomicroscopy or indirect ophthalmoscopy of the fundus may prove impossible even for the most experienced clinician. We investigated the feasibility of using an ultra-wide angle imaging system to study the retina in eyes where indirect ophthalmoscopy could not be accomplished.
Using the Optos P200A system, we evaluated a series of 20 patients where a view to the retina was precluded because of dense cataract (8 eyes), corneal edema (4 eyes), keratic precipitates (4 eyes), small pupils (6 eyes), pupillary membranes (2 eyes), or vitreous hemorrhage (6 eyes). The primary outcome measure was a fundus or fluorescein angiographic image that was deemed to reveal sufficient information, as assessed by an independent retinal specialist, from which clinical treatment decisions could be made.
Clinically useful retinal details were revealed in 85% of eyes using this technique. In 6 eyes, fluorescein angiography was successfully performed despite the fact that substantial vitreous hemorrhage or dense vitreous opacities were present. Angiography revealed the cause of the hemorrhage in 5 of 6 eyes. Moderate to severe corneal edema degraded the images substantially, presumably secondary to light scatter, and represented a major impediment to imaging. Lens opacities proved much less problematic, even with 4+ nuclear sclerotic cataracts. Conventional photography failed to produce any interpretable retinal images in these eyes. The likely explanation for the utility of the Optos system in scanning through media opacities is the narrow illuminating beam (0.3mm), and long wavelength laser beam (633 nm). Both act to reduce back scatter induced by media opacities.
While ultra-wide angle imaging is used primarily to obtain an image of the sensory retina in a single exposure, a specialized, simple, yet potentially important clinical application of such a system is the clinical assessment of eyes with dense media opacities. Substantial corneal edema was a greater impediment to imaging than lens or vitreous opacities, in general.
This PDF is available to Subscribers Only