Effects of Cataract on Optic Nerve Head and Macular Analysis Using Optical Coherence Tomography

Purpose: To assess the impact of cataract on optic nerve head (ONH) parameters (disc area, rim area, average cup/disc ratio, vertical cup/disc ratio, cup volume), peripapillary retinal nerve fiber layer (pRNFL) thickness, and macular ganglion cell-inner plexiform layer (mGC-IPL) thickness in patients with glaucoma and in a control group. Methods: A retrospective analysis was conducted on medical records from January to December 2021 for individuals undergoing cataract surgery. This group included normal, glaucoma suspects, and glaucoma patients, totaling 44 individuals and 63 eyes. Measurements of ONH parameters, pRNFL thickness, and mGC-IPL thickness were taken using spectral-domain optical coherence tomography before and after surgery. We analyzed postoperative changes in these parameters and related factors to preoperative segmentation errors. Results: In glaucoma patients, a significant increase in the average thickness of the pRNFL (p = 0.002) was observed after surgery, while no significant changes were seen in ONH parameters and the average thickness of the mGC-IPL (all p > 0.05). Conversely, the control group showed an increase in some areas of mGC-IPL thickness after surgery (p < 0.05). Multivariate regression analysis indicated that in glaucoma patients, thinner preoperative pRNFL and mGC-IPL thickness were predictors of increased average thickness after surgery (p < 0.001 and p = 0.008, respectively). Conclusions: Cataract significantly impacts the pRNFL and mGC-IPL thickness in glaucoma patients, with less effect on ONH parameters. These findings suggest that ONH parameters can be more reliable for monitoring patients undergoing cataract surgery and assessing glaucoma progression simultaneously.