Spectral-Domain Optical Coherence Tomography and Multifocal Electroretinography Results in the Long-Term Follow-Up of Glaucoma Patients

Objective: To investigate the changes in macular retinal layers and panretinal neuroretinal functions in the long-term follow-up of patients with primary open-angle glaucoma.

Materials and Methods: Forty-one patients diagnosed with primary open-angle glaucoma were followed up for 12 months. According to their mean deviation (MD) values), the patients were put into two groups as Group 1 with early stage glaucoma (MD≥-6) and Group 2 with middle-advanced stage glaucoma (MD<-6). Optical coherence tomography (OCT) and multifocal electroretinography (mfERG) were performed at the baseline and at the sixth- and 12th-month evaluations. The OCT, retinal layer and mfERG findings were compared between the two groups.

Results: There was no statistically significant difference between the groups in terms of gender and age In Group 2, the mean baseline macula Retina Nerve Fiber Layer, Ganglion Cell Layer and Inner Pleksiform Layer measurements were lower in each quadrant compared to Group 1. Concerning progression in OCT measurements, there was no significant difference between the two groups. However, it was noteworthy that in Group 2, there was a decrease especially in the first and second ring amplitudes of the P1 and N2 waves and prolongation of the implicit time. At the 12-month evaluation, there was prolongation of the implicit time of the N1 wave and a decrease in the P1 wave amplitude in Group 1.

Conclusion: Retinal layers are affected in patients with intermediate and advanced stage glaucoma. In the follow-up of early stage glaucoma patients, mfERG measurements can show damage that may occur.