Prevalence of Blue Sclera in the United States
Blue sclera is primarily associated with osteogenesis imperfecta (OI) and has an estimated prevalence of 1 in 5,000 individuals in the United States, though this figure may be underestimated due to variable clinical presentations and limited awareness among healthcare professionals.
Definition and Appearance
Blue sclera refers to the bluish discoloration of the normally white sclera (the outer coating of the eyeball). This coloration occurs due to increased visibility of the underlying uveal tissue through an abnormally thin sclera, which is most commonly associated with connective tissue disorders.
Prevalence by Associated Conditions
Osteogenesis Imperfecta
- Blue sclera is a characteristic feature of OI, particularly in OI type I, where it remains intensely blue throughout life 1
- In OI types III and IV, the sclera may be blue at birth and during infancy, but the intensity fades with time, becoming normal by adolescence 1
- OI has an estimated prevalence of 1 in 5,000 individuals in the United States 2
Ehlers-Danlos Syndrome (EDS)
- Blue sclera is also a feature of EDS, which has an estimated prevalence of 1 in 5,000 individuals in the United States 2
- The true prevalence may be underestimated due to variable clinical presentations and limited awareness among healthcare professionals 2
Diagnostic Considerations
- The 'BLUES' (BLUe Eye Sclera) procedure has been developed to objectively identify and quantify blue sclera in patients with OI, with 89% sensitivity and 87% specificity 3
- The optimal cut-off point for diagnosing blue sclera using this method is a scleral blue peak of 17% 3
Clinical Significance
- Recognition of blue sclera is clinically important as it could prompt a more thorough diagnostic evaluation of possible systemic and dental malformations 4
- Blue sclera can be associated with 66 genetic syndromes, 8 non-genetic disorders, and 4 pharmacologically induced pigmentations 4
- In patients with OI, blue sclera is often accompanied by increased bone fragility, with fractures occurring after minor trauma 5
Management Implications
- Identification of blue sclera should trigger consideration of underlying systemic conditions, particularly connective tissue disorders
- For OI patients with blue sclera, bisphosphonates may be considered to reduce significantly increased bone turnover 5
- Regular ophthalmologic follow-up is recommended for patients with blue sclera to monitor for associated ocular complications
Blue sclera is an important clinical sign that can indicate underlying systemic disorders. While specific prevalence data for blue sclera alone in the United States is not well documented, its association with conditions like OI and EDS suggests it affects approximately 1 in 5,000 individuals, though this may be an underestimate.