Patients with myopia are at increased risk for the development of glaucoma. The inability to correct for axial length on spectral domain OCT (SD-OCT) imaging translates into a lower signal strength and scan reliability in patients with high myopia. We evaluated the effectiveness of a contact lens to increase the signal strength, assess optic nerve dimensions and nerve fiber layer thickness using SD-OCT in patients with glaucoma or who are glaucoma suspects with high axial myopia.
Methods- A single-center, prospective, interventional study of patients with axial lengths over 25.5 mm with a diagnosis of glaucoma or glaucoma suspect. The optic nerve cube 200 x 200 scan using the Cirrus SD-OCT 400 was taken first without and then repeated after the placement of the contact lens. The primary outcome measure was the change in the average nerve fiber layer thickness before and after use of the contact lens. Secondary outcome measures included the change in cup volume, disc area, and rim area.
Results- Twelve patients were recruited (20 eyes) and the average axial length was 27.06 mm and the average signal strength interval increased by 1.73 (p= 0.001). With the use of a contact lens, the average nerve fiber layer thickness was significantly thicker. None of the changes in the secondary outcome measures were significant: rim area, cup volume, or disc area. Conclusions- Based on our data, the use of a contact lens statistically improved the signal strength and average nerve fiber layer thickness of the SD-OCT scan. The ability to accurately capture the perimeter of the optic disc can 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 to discern if contact lens correction has a greater effect on the highest axial lengths are needed.
Meghan K. Berkenstock: Dr. Berkenstock has become an emerging leader in the field of ocular immunology. As an Assistant Professor of Ophthalmology at the Wilmer Eye Institute of the Johns Hopkins School of Medicine, her research focuses on quality improvement and identifying and treating ocular side effects of oncologic immunotherapy medications.