Purpose: We aimed to investigate whether macular pigment optical density (MPOD) has a diagnostic value by comparing MPOD and retinal nerve fiber layer (RNFL), ganglion cell layer++ (GCL++) of patients with primary open-angle glaucoma (POAG) and pseudoexfoliation (PEX) glaucoma and normal individuals.
Methods: We included in the study 54 eyes of 34 patients with diagnosis POAG, 40 eyes of 25 patients with PEX glaucoma and 40 eyes of 20 normal individuals. The MPOD measurements of the cases were performed in the MPOD mode of the fundus fluorescein angiography (Carl Zeiss Visucam Meditec, Germany) device while the pupils were in dilated status. RNFL and GCL++ measurements of all individuals included in the study were done by swept source optical coherence tomography (DRI Triton swept source optical coherence tomography; Topcon, Tokyo, Japan). Intraocular pressures of all three groups were measured by Applanation tonometer. The relationship between MPOD, RNFL and GCL++ values were examined. Patients with additional ophthalmic disease, intraocular surgery, history of chronic drug use, and smokers were excluded in the study.
Results: MPOD mean and MPOD max values were significantly higher in patients with PEX glaucoma than POAG and control group (p < 0.05). MPOD mean and MPOD max measurements were not different when compared to POAG patients and control group (p > 0.05). RNFL and GCL++ measurements were found significantly thinner in patients with POAG and PEX glaucoma compared to the control group (p < 0.001). There was no correlation between MPOD values and RNFL or GCL++. MPOD max values show a very high correlation with age in a statistically significant positive direction (r = 0.90, p < 0.001). The average age of PEX glaucoma group was higher than the control group (p = 0.006). There was no age difference between the PEX glaucoma group and the POAG group (p > 0.05). Also, there was no difference in age between POAG and control groups. In POAG and PEX glaucoma groups, mean intraocular pressure values are significantly higher than the control group.
Conclusions: In our study, no MPOD change was observed in the POAG group, while a statistically significant increase in MPOD was found in the PEX glaucoma group. As a result of these findings, we think that PEX syndrome also affects the posterior segment. Well-organized, large, prospective, and randomized studies should be developed for preventive treatment to the negative effects of PEX syndrome on all eye tissues.
Keywords: Ganglion cell complex; Macular pigment optical density; Primary open-angle glaucoma; Pseudoexfoliation glaucoma; Pseudoexfoliation syndrome; Retinal nerve fiber layer.