Anterior scleral thickness in Marfan syndrome: A quantitative analysis

Purpose

To investigate the anterior scleral thickness (AST) in patients with Marfan syndrome (MFS).

Methods

A prospective, cross-sectional study was conducted at the Department of Ophthalmology, Ghent University Hospital, Ghent, including patients with a genetically confirmed clinical diagnosis of MFS and age-, gender- and axial length-matched controls. Subjects with known corneal, conjunctival or scleral pathology and a history of ocular surgery, including pars plana vitrectomy, recent contact lens use or high-grade astigmatism were excluded. Subjects underwent non-cycloplegic autorefraction, Scheimpflug-based corneal tomography, axial length measurement and spectral-domain optical coherence tomography (OCT). AST was manually measured at 1 mm (AST1), 2 mm (AST2) and 3 mm (AST3) from the scleral spur, temporally and nasally.

Results

A total of 56 subjects (28 subjects in the MFS group and 28 matched subjects in the control group) were included in this study. In patients with MFS, AST was significantly reduced compared to matched controls, both overall and at every analysed measuring point in the nasal and temporal areas (p < 0.001). Central corneal thickness (CCT) and mean keratometry (Kmean) values were significantly lower in patients with MFS (p < 0.05). A positive correlation was found between nasal AST and CCT in patients with MFS. No correlation was found between AST and Kmean or between AST and axial length. In patients with MFS with ectopia lentis, compared to those without, temporal AST3 was significantly lower (p < 0.05). AST was significantly lower in patients with MFS harbouring a variant predicted to cause haploinsufficiency compared to those with a variant expected to lead to a dominant negative effect for both nasal and temporal measurements.

Conclusion

Based on anterior segment OCT measurements, AST of patients with MFS is significantly lower compared to matched controls.