OBJECTIVE: To determine the relationship between hypothyroidism and color vision deficiency among Filipinos ages 20-60 years
DESIGN AND METHODS: A cross-sectional study was performed on 91 biochemically hypothyroid and euthyroid patients seen at the Makati Medical Center from July to December 2013. All subjects underwent the Ishihara color test, followed by the Farnsworth-Munsell D15 test if this was positive. The patient who tested positive in the Farnsworth-Munsell D15 test was referred to an ophthalmologist to rule out any anatomic problem, and was excluded from the study if found to have any. Fisher's exact test assessed the significant correlation between hypothyroidism and color vision deficiency. A p-value less than 0.05 was considered significant.
RESULTS: Of the 91 patients that were included in the study, the average age was 42 years, majority (87%) were females, and 41% were biochemically hypothyroid. All euthyroid patients (100%) had normal color vision, while one hypothyroid patient (3.0%) tested positive for color vision deficiency (p-value 0.407).
CONCLUSION: Based on this study, the hypothyroid state of the patients had no effect on their color vision, unlike those seen in rodents, probably because mature human cones are not as easily affected by changes in thyroid hormone levels.