Increased microvascular disease in X-linked and autosomal recessive Alport syndrome: a case control cross sectional observational study

Background: Retinal microvascular disease reflects, in part, poor blood pressure control and systemic microvascular disease contributes to renal failure progression. This study examined the retinal microvasculature in Alport syndrome. Materials and Methods: Retinal images from 28 males and 28 females with X-linked Alport syndrome, and 13 individuals with autosomal recessive disease were reviewed retrospectively for microvascular/ hypertensive retinopathy (Wong and Mitchell classification), and small vessel calibre (using a computerised semiautomated method and revised Knudtson formula). Data were compared with age and gender-matched individuals with normal blood pressure and renal function. Results: Microvascular/hypertensive retinopathy was more common in males and females with X-linked Alport syndrome than age- and gender-matched controls (23, 82% and 10, 36%, p < 0.01; and 21, 75% and 13, 48%, p = 0.05, respectively), and in individuals with autosomal recessive disease compared with controls (12, 92% and 16, 43%, p < 0.01). Moderate microvascular/hypertensive changes were present in males and females with X-linked or autosomal recessive disease but not controls. Arteriolar calibre was reduced in males with X-linked disease (142.5 +/- 18.7 mu m, and 150.7 +/- 10.1 mu m, p = 0.046) and in autosomal recessive disease (133.5 +/- 11.10 mu m and 149.1 +/- 10.6 mu m, p < 0.0001). Microvascular/hypertensive retinopathy and arteriolar narrowing in males with X-linked disease were not different after renal transplantation and before (p NS). Conclusions: Microvascular/hypertensive retinopathy was more common and more severe in Alport syndrome than normotensive controls. Improved BP levels may further slow the rate of renal functional decline in Alport syndrome.