Macular Optical Coherence Tomography Findings in Patients with Methanol Toxicity: A Cross-Sectional Study
Mojtaba Abrishami1 *, Mohammad Moshiri2
- Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
- Medical Toxicology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Abstract: To evaluate the course of Optical Coherence Tomography (OCT) changes in methanol toxicity (MT) cases.
Methods: This cross-sectional study included MT patients referred to two tertiary referral toxicology centers in southeast Iran between March 2021 and March 2022. The diagnosis of MP was based on harmful methanol serum concentrations or strong clinical suspicion. The participants' retinal and choroidal thickness were evaluated by OCT, and the results were compared with those of the normal population reported in other studies.
Results: A total of 39 patients, with an average age of 33.79±11.18 years and mean methanol serum level of 46.38±35.8 mg/dL, were included in the study. The mean choroidal thickness of the right and left eyes was 403.84±67.6 μm and 387.1±57.8 μm, respectively. The mean foveal thickness of the right and left eyes was 258.33±8 μm and 260±24 μm, respectively. These measurements were significantly higher than the average thickness observed in the healthy population (P < 0.05). Thickness of the macula in all six partitions increased, and the retinal nerve fiber layer (RNFL) and choroid exhibited substantial augmentation in thickness (P < 0.05). No notable association was found between the quantity of methanol consumed and the rise in macular thickness. Analysis of VBG parameters showed a correlation between BCVA (logMAR) and pH in both eyes (OS: r = -0.489, p = 0.029; OD: r = -0.561, p = 0.010). No association was found between bicarbonate (HCO3), PCO2, and BCVA.
Conclusion: MT led to thickening of the retina, an increase in RNFL, notable choroidal alterations, and a decline in visual acuity. The concentration of methanol in blood serum did not significantly correlate with these changes in visual acuity.
