OCT Normative Data Insufficient for Latin Americans with Mild, Moderate Myopia

Myopia can cause RNFL thinning that mimics glaucoma on OCT. While OCT normative data can help distinguish the two conditions, new research shows that it may not perform adequately in certain ethnic populations; specifically, they found that OCT norms couldn’t distinguish myopia-related RNFL thinning from glaucoma in Latin Americans with severe myopia. Photo: Andrew Rouse, OD. Click image to enlarge.  A patient’s race or ethnicity can play a key role in the morphology of their conditions, which influences how the disease is monitored and managed. This is why it’s important to develop normative databases for different populations, something that a team of researchers from Columbia recently set out to do. Specifically, they assessed Latin American myopes’ optic nerve head and ganglion cell complex (GCC) morphology in order to better characterize retinal nerve fiber layer (RNFL) and GCC thinning in this specific population. Their findings were presented last week at ARVO 2025 in Salt Lake City.Between 2022 and 2024, myopic patients were analyzed at a single referral center in Columbia and underwent optical coherence tomography (OCT). Patients were selected if they presented without a history of glaucoma, inflammatory or infectious diseases and did not undergo refractive or filtering surgeries. Each patient that met this criterion had their myopia categorized as mild, moderate or severe. A total of 180 eyes from 90 patients were selected for this study.A majority of patients’ myopia was moderate (101 eyes; 56.1%), followed by mild (64 eyes; 35.5%) and severe (15 eyes; 8.3%) cases. Researchers noted that severe cases had an increase in peripapillary atrophy in both their alpha and beta zones, lower vertical cup-to-disc ratios and smaller cup areas. Additionally, these cases showed thinning in the inferior GCC and nasal and inferior RNFL.Since RNFL thinning from myopia can mimic glaucoma on OCT, they used a color scale to understand whether the OCT measurements they assessed could adequately determine the need for glaucoma assessment in myopic cases. Patients’ measurements in line with the green scales were determined as adequate, or normative, compared to baseline measurements, while yellow and red scale measurements needed further assessment to determine whether a case is thinning of the RNFL or glaucoma. Nearly all severe cases fell under the green scale, while mild and moderate cases had measurements that fell under the yellow and red scales.“Existing OCT normative data are sufficient for severe myopia but insufficient for mild and moderate cases in a Latin population, proving the need for specific normative databases that allow a more reliable assessment of glaucoma in myopic eyes,” concluded the authors in their abstract.Original abstract content ©2025 Association for Research in Vision and Ophthalmology. Goyeneche HFG, Pinzon LZ, Forero MAV. Characterization of the optic nerve head by optical coherence tomography in myopic patients from a Latin American population. ARVO 2025 annual meeting.