This article is more than 5 years old. Information may no longer be current.
SS-OCT effective for detecting early glaucoma
Click Here to Manage Email Alerts
Wide-field retinal nerve fiber layer maps using swept-source optical coherence tomography showed increased ability to detect signs of early glaucoma as compared with the conventional OCT parameters, namely circumpapillary RNFL thickness measurement and ganglion cell analysis.
In a retrospective study, 43 eyes with preperimetric glaucoma, 74 eyes with early perimetric glaucoma and 67 heathy eyes were imaged by SS-OCT using a wide-field single scan protocol. This allowed the imaging of a large, 12 x 9 mm area including the macula and optic nerve in a single scan of only 1.3 seconds. Conventional circumpapillary retinal nerve fiber layer (cpRNFL) thickness and macular ganglion cell measurement were also performed.
In some cases, wide-field RNFL thickness maps were able to detect early structural changes that were not detected with the conventional method.
As noted by the authors, the superior performance of wide-field RNFL maps is related to the higher sensitivity in visualizing the temporal margin of the RNFL defect and the ability to visualize defects apart from the optic disc. In a single scan, they provide “a wealth of information simultaneously, and the results are presented in a single, at-a-glance printout,” including wide-field RNF thickness map, SuperPixel map, clock-hour and four-quadrant cpRNFL thickness and color-coded map, ganglion cell layer with the inner plexiform layer and RNFL thickness, and color-coded map on a macular six-sector grid.
According to the authors, “this scan protocol can lower the missing rate and reduce the examination time. The examination, therefore, can be very effective, economic, time-saving and comfortable for the patients.”
They suggested using it as a complementary or alternative imaging modality to the conventional method. – by Michela Cimberle
Disclosure: The authors declare no conflict of interest.
Perspective
Back to Top
Scott Anthony, OD, FAAO
Despite significant progress in OCT imaging of the inner retinal layers that are known to be biometrically thin with glaucoma, clinicians are faced with ever changing ways to integrate new analyses into our current management schemes. The abundance of information that we gain with new OCT technologies and scanning techniques can be put to good use, but must be done so carefully and with the knowledge to apply them in practice.
I am extremely excited to see new imaging techniques such as wide-field swept-source OCT introduced into the glaucoma arena. Although I’m still navigating the nuances of adding ganglion cell layer measurements to my glaucoma OCT protocol, this study introduces a potential new parameter to this mix that should fit in seamlessly with our glaucoma diagnostic strategies.
If you are feeling a bit lost in this OCT imaging revolution, rest assured that these studies, by-and-large, identified glaucoma with a careful funduscopic or photographic evaluation of the optic nerve and RNFL, which should nearly always guide your diagnostics when integrating OCT into your glaucoma practice.
Click Here to Manage Email Alerts