Skin Melanin Affects FAZ Morphology, Study Finds

An observational study identified a positive correlation between skin melanin index and FAZ area; specifically, every 100-unit increase in melanin index was associated with a 0.12mm2 increase in FAZ area. According to the authors, this finding highlights “the importance of pigment-related pathways in shaping normal retinal architecture.” These images from the study show (left) a smaller and more irregular FAZ in a low-pigment subject and (right) study data showing a significant positive correlation between FAZ and the melanin index. Photo: Folegani V, et al. Invest Ophthalmol Vis Sci. 2026;67(3):43. Click image to enlarge. A new cross-sectional study revealed a significant connection between skin pigmentation and foveal avascular zone (FAZ) size in healthy Caucasian adults. This suggests that physiological pigmentation influences OCT angiography (OCT-A)-derived FAZ metrics that clinicians increasingly use as biomarkers in ocular and systemic disease. The study findings, published last week in Investigative Ophthalmology & Visual Science, are summarized below.A total of 154 white adults with a BCVA of 20/25 or better and no history of ocular or systemic disease were enrolled from an eye clinic in Milan. Researchers randomly selected one eye to study in each participant, the majority of whom were female (68.8%) with an average age of 32 years (range: 26 to 51 years). The FAZ area of each eye was manually segmented from OCT-A images, while skin melanin content was quantified with a colorimeter at three standardized anatomical sites to derive a melanin index. Various analyses were conducted to examine associations among the melanin index, FAZ area, axial length, central foveal thickness and the presence of persistent foveal inner retinal layers.A significant positive association emerged between the melanin index and FAZ area. In multivariable modeling, each 100-unit rise in the melanin index corresponded to a 0.12mm² increase in FAZ area. Conversely, age, sex and axial length were not associated with FAZ size. Additionally, lower melanin levels were linked to a higher likelihood of persistent foveal inner retinal layers (odds ratio per unit increase in melanin index = 0.98) and greater central foveal thickness.In their paper, the study authors conveyed, “Our findings support the hypothesis that melanin contributes to the developmental and regulatory processes involved in foveal morphogenesis, highlighting the importance of pigment-related pathways in shaping normal retinal architecture.” Therefore, they proposed “that variations in skin pigmentation, often overlooked in clinical and research settings, should be taken into account alongside ethnicity, axial length and comorbidities when interpreting FAZ metrics as biomarkers in common retinal diseases.”Click here for the journal source. Folegani V, Cozzi M, Menghi A, et al. Skin melanin content and the foveal avascular zone correlation in a healthy white population. Invest Ophthalmol Vis Sci. 2026;67(3):43.  This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.