A Report by the American Academy of Ophthalmology Ophthalmic Technology Assessment Committee Glaucoma Panel: Hana L. Takusagawa, MD1 Ambika Hoguet, MD,2 Anna K. Junk, MD,3 Kouros Nouri-Mahdavi, MD, MS,4 Sunita Radhakrishnan, MD,5 Teresa C. Chen, MD6
Ophthalmology, Vol. 126, p1315–1323, © 2019 by the American Academy of Ophthalmology. Click here for free access to the OTA.
Purpose: To review the published literature on the use of swept-source (SS) OCT for evaluating the lamina cribrosa in glaucoma.
Methods: A PubMed and Cochrane Library literature search initially conducted on March 3, 2017, and updated on June 26, 2018, yielded a total of 64 articles. Articles that were reviews or that were not published in English were excluded, and 29 were found to fit the inclusion criteria. The panel methodologist then assigned a level of evidence rating to each study. Fifteen studies were rated level III, 14 studies were rated level II, and no studies were rated level I.
Results: Different aspects of the lamina cribrosa were studied using SS-OCT, including the anterior lamina cribrosa curvature, anterior lamina cribrosa depth, anterior lamina cribrosa insertions, laminar thickness, focal lamina cribrosa defects (FLCDs), and lamina cribrosa microarchitecture. In general, imaging of the anterior lamina can be achieved reliably, although shadowing from blood vessels at the neuroretinal rim remains an issue. Imaging of the posterior lamina can be achieved with varying levels of success. In glaucoma, there is posterior migration of the anterior lamina cribrosa insertions as well as increased thinning and posterior curvature of the lamina cribrosa. Focal lamina cribrosa defects appear more commonly in glaucoma, and this may hint at the pathogenesis of axonal damage. In addition, there may be remodeling of the microarchitecture of the lamina, resulting in more variable laminar pores. There are limited studies comparing SS-OCT with spectral-domain (SD) OCT with regard to imaging of the lamina, but the difference in image quality between enhanced depth imaging (EDI) with SD-OCT and SS-OCT seems minimal.
Conclusions: Imaging of the lamina cribrosa using SS-OCT has demonstrated that the lamina cribrosa is likely biomechanically active and that significant changes occur in glaucoma. The diagnostic utility of SS-OCT for lamina cribrosa imaging is promising, but standardized nomenclature, automated measurements, and longitudinal studies with larger and more diverse sample sizes are needed.
1 The Eye Center, Eugene, Oregon, and Casey Eye Institute, Oregon Health & Sciences University, Portland, Oregon
2 Ophthalmic Consultants of Boston, Boston, Massachusetts
3 Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida and Miami Veterans Affairs Healthcare System, Miami, Florida
4 Stein Eye Institute, Los Angeles, California
5 Glaucoma Center of San Francisco, Glaucoma Research and Education Group, San Francisco, California
6 Harvard Medical School, Department of Ophthalmology, Massachusetts Eye & Ear Infirmary, Glaucoma Service, Boston, Massachusetts