Patients who have low levels of vitamin C are likely to have decreased foveal thickness and choroidal thicknesses, according to a study published in BMC Ophthalmology. Researchers believe that the finding suggests that vitamin C deficiency influences the onset of some retinal and choroidal diseases, according to the report.
Researchers reviewed the cases of 69 participants with vitamin C deficiency (mean age, 57.26±14.16 years) and 69 participants without it (58.13±12.37 years), who reported to a hospital between May and December 2019. Clinicians collected blood samples (for vitamin analysis), and ocular examination data for each participant. Swept-source optical coherence tomography (SS-OCT) was used to determine retinal and choroidal thicknesses. All participants had best corrected visual acuities (BCVA) of at least 20/25, a refractive error between +3.0 to -3.0 D, intraocular pressure (IOP) between 10 mm Hg and 21 mm Hg, and no presence of systemic disease, inherited disease, or past retinal surgery.
The investigation found retinal thickness in the vitamin-C deficient group was significantly lower than in the nondeficient group (269.07±13.51 vs 276.92±13.51 μm, P =.001, respectively). The average subfoveal choroidal thickness was also significantly lower patients who were vitamin C deficient compared with patients in the control group (195.62±66.40 μm vs 238.86±55.08 μm; P <.001, respectively).
This study is limited by its small sample size. Additionally, researchers did not account for smoking history among patients, which could affect the results considering the link between smoking and choroid thinning. Also, the researchers did not document the levels of vitamin C in each patient’s blood past normal or deficient.
Many links between retinal and choroidal disease and oxidative stress exist in the literature. Because a known cause of oxidative stress is thought to be vitamin C deficiency, the researchers suggest there may be a connection between retinal and choroidal disease and decreased vitamin C levels.
“Vitamin C is an important antioxidant which can prevent the oxidative damage to the retina,” researchers explain. “A high level of vitamin C in [the] retina alleviates free radicals and improves immune cell function generated by its high metabolic activity.”
Qian X, Wang L, Qiang X, et al. Choroidal and retinal thickness in patients with vitamin C deficiency using swept-source optical coherence tomography. BMC Ophthalmol. Published online July 18, 2022. doi:10.1186/s12886-022-02530-8