Abstract
PURPOSE: To determine the association between ABO and Rh blood groups with retinal structural indices including macular thickness and peripapillary retinal nerve fiber layer (RNFL) thickness. METHODS: This cross-sectional study was conducted using convenience sampling in a tertiary referral eye hospital in Tehran, Iran. Study participants were referred to the hospital laboratory to test their blood group. Ocular examinations were performed including measurement of visual acuity, auto-refraction, subjective refraction, and slit-lamp biomicroscopy. Retinal imaging was carried out using Spectral-domain OCT under dilated papillary conditions. RESULTS: Three hundred and twenty-eight individuals were recruited in this study. Of these, 219 (60.7%) were female and the mean age of the participants was 63.29 ± 5.57 years (range: 56 to 83 years). According to the multiple linear regression model, the global peripapillary RNFL thickness [coefficient: -3.05 (95% CI: -5.30 to -0.74); P = 0.010] and peripapillary RNFL thickness in the superior [coefficient: -4.65 (95% CI: -8.40 to -0.89), P < 0.001] and inferior [coefficient: -4.00 (95% CI: -7.81 to -0.19); P = 0.040] quadrants were significantly thinner in individuals with blood type B compared to those with other ABO blood groups. The average [coefficient: 12.69 (95% CI: 4.12-21.64); P = 0.004) and central [coefficient: 16.21 (95%: 6.44-25.97); P = 0.001) macular thicknesses were significantly thicker in AB group compared to other blood groups. The average macular thickness was significantly thinner in Rh + compared to the Rh- group [coefficient: -8.33 (95% CI: -15.4 to -1.25); P = 0.021]. CONCLUSION: Retinal structural indices may be related to blood groups implying a genetic linkage. Considering the lack of consistency among various studies, larger trials are needed to explore the effect of ABO and Rh grouping on peripapillary RNFL and macular thicknesses.