A new scoring system that includes optical coherence tomography (OCT) topographic parameters may be beneficial for clinicians to differentiate real glaucomatous damage from myopic healthy eyes, according to research published in Ophthalmology.

The cross-sectional study enrolled 517 patients, including 175 highly myopic eyes. The participants were divided into two test sets: 241 study eyes and a validation set of 276 eyes.

Researchers selected retinal nerve fiber layer (RNFL) and ganglion cell–inner plexiform layer (GCIPL) topographic signs based on the morphologic patterns of RNFL (size, shape, location and agreement between deviation and thickness maps) and GCIPL (size, shape, location, color tone, agreement between maps and step sign) abnormalities indicative of higher likelihood of myopic glaucoma. They compiled the diagnostic score according to the sensitivity, specificity and positive likelihood ratio of each diagnostic sign using the training set, and used statistical measures to compare the OCT-provided parameters with the scoring system in the validation set.

Among all the RNFL and GCIPL parameters, the researchers found the presence of temporal hemifield asymmetry on the GCIPL thickness map showed the highest diagnostic ability, followed by location of the RNFL defect and color tone of the GCIPL defect. For highly myopic eyes, the scoring system also showed a higher diagnostic performance than that of the RNFL and GCIPL thickness parameters.

“Our scoring system including OCT topographic parameters demonstrated to be beneficial for clinicians to differentiate real glaucomatous damage from myopic healthy eyes,” the researchers wrote. "Our results support the value of using multitopographic OCT parameters for detecting glaucoma in myopic eyes."