Reproducibility Of Retinal Nerve Fiber Layer And Macular Volume Measurements In Patients Receiving Retinal Protection Pharmacotherapy

Background — High-quality monitoring of the glaucoma plays an important role in the early diagnosis and treatment of glaucoma, for which structural optical coherence tomography (OCT) is used. Technology that increases the repeatability and reproducibility of OCT may differ in different devices, thereby yielding different results. Objective — To assess the effect of the frequency of retinal protection pharmacotherapy courses on quantitative data regarding the macular volume and the thickness of the retinal nerve fiber layer (RNFL) measured by two instruments, SPECTRALIS and OPTOPOL, and also to evaluate the agreement between the data collected by these devices. Material and Methods — We monitored 17 patients (34 eyes) diagnosed with primary open-angle glaucoma in the advanced stage from 2019 to 2023. Group 1 including 9 patients (18 eyes) received a course of retinal protection pharmacotherapy with Retinalamin® at an interval of 3 months, while Group 2 comprising 8 patients (16 eyes) received similar treatment at an interval of 6 months. All observed patients underwent structural OCT on REVO NX (OPTOPOL Technology) and SPECTRALIS devices at the onset of the study, as well as after 3 and 6 months. Results — The agreement between the two devices in measuring RNFL thickness was estimated by the Lin’s concordance correlation coefficient (LCCC): in manual mode, LCCCstart=0.69 (95% CI: 0.51-0.81); while in automatic mode, LCCCstart=0.73 (95% CI: 0.57-0.84). The agreement between the macular volume measurements was as follows: in manual mode, LCCCstart=0.21 (95% CI: 0.21-0.29); while in automatic mode, LCCCstart=0.21 (95% CI: 0.21-0.29). Conclusion — The agreement between the SPECTRALIS and OPTOPOL devices in terms of RNFL thickness should be considered substantial, while in terms of macular volume, it should be classified as fair. As measured in the manual mode, the RNFL thickness in both groups receiving Retinalamin increased, which can be interpreted as a favorable effect of retinal protection pharmacotherapy.