Research suggests that individuals with retinitis pigmentosa (RP) may benefit from a dietary iodine supplement. RP patients often experience retinal swelling as a result of Cystoid Macular Edema (CME). A study published in JAMA Ophthalmology showed swelling due to CME to be inversely related to iodine intake.
The study was conducted by researchers from Massachusetts Eye and Ear, Harvard Medical School, and Boston University School of Medicine. Using a sample of 212 RP patients at Massachusetts Eye and Ear, the observational study measured central foveal swelling in relation to iodine levels estimated from urine samples. Patients were aged 18 to 69, did not smoke, and had no worse than 20/200 visual acuity in at least one eye.
The observation showed an inverse relationship between swelling from CME and urinary iodine levels. Those patients with the lowest concentrations of iodine in their system tended to experience the highest amount of retinal swelling.
After this initial study, further research into the relationship between iodine intake and swelling due to CME are required. These findings may suggest that an iodine supplement could be used to limit or reduce swelling in RP patients with CME.
Study: “The Relationship of Central Foveal Thickness to Urinary Iodine Concentration in Retinitis Pigmentosa With or Without Cystoid Macular Edema” by Michael A. Sandberg et. al. JAMA Ophthalmol. 2014;132(10):1209-1214. doi:10.1001/jamaophthalmol.2014.1726.