Contact lenses are a staple in vision correction, but they may also help produce better spectral-domain OCT (SD-OCT) images of the optic nerve in patients with high myopia and glaucoma, a study in Ophthalmology Glaucoma reports. Currently, practitioners cannot correct for axial length on OCT, often creating lower signal strength and scan reliability, the researchers noted.
The team from the Wilmer Eye Institute enrolled 12 patients (20 eyes) with an average axial length of 27.06mm to evaluate contact lenses’ ability to increase signal strength and improve optic nerve dimension and nerve fiber layer thickness in SD-OCT imaging.
Testing included optic nerve cube 200x200 scans on patients with and without contact lenses. The primary outcome was change in the average nerve fiber layer thickness, and the secondary outcome included changes in cup volume and disc and rim areas.
The investigators found the average signal strength interval increased by 1.73, and the contact lenses, when worn during imaging, also significantly increased nerve fiber layer thickness.
However, none of the changes in the secondary outcome measures were noteworthy.
The researchers also reported the ability to accurately capture the perimeter of the optic disc could be limited in the setting of peripapillary atrophy, which was present in all but two subjects.
Future studies with a larger number of subjects and a wider range of axial myopia may be necessary to determine if contact lens correction has a greater effect on the highest axial lengths, the researchers noted.
|Berkenstock MK, Parikh RA, Collins MD, et al. Use of contact lenses to optimize optical coherence tomography scans of the optic nerve in open angle glaucoma suspects or patients with open angle glaucoma with high myopia. Ophthalmol Glaucoma. January 14, 2020. [Epub ahead of print].|