Abstract
Purpose :
Marfan syndrome (MFS) is a connective tissue disorder with manifestations in the cardiovascular, musculoskeletal and ocular systems. MFS affects approximately 1:3,000 people; it is inherited in autosomal dominant fashion, caused by mutations in the FBN1 gene on chromosome 15. The ocular features consist of lens dislocation, increased axial length, presenile cataract formation, open angle and phacolytic glaucoma, and retinal detachments. The purpose of this study is to evaluate the utility of ultrasound biomicroscopy (UBM) in quantifying lens subluxation and zonular stability.
Methods :
We conducted a retrospective review of UBM exams of 8 eyes of 4 patients with MFS aged 21-43 years; diagnosis was confirmed using Ghent II criteria. Eight eyes of 4 age-matched normal patients in our database were measured for comparison. Examinations were performed using Quantel Aviso UBM system with 50 MHz probe. We measured anterior chamber (AC) depth, lens thickness, anterior radius and displacement from the pupil center as well as appearance of the zonules.
Results :
Central AC depth averaged 2.59±0.39 mm in MFS versus 2.92±0.38 mm in controls. Lens thickness averaged 4.3±0.6 mm in MFS patients versus 3.9±0.4 for controls and the anterior radius of curvature averaged 6.3±2.1 mm in MFS versus 9.8±1.5 mm in controls. The difference in anterior lens radius from controls was statistically significant (p=.002). The lens was displaced superonasally in 3 eyes, superotemporally in 1 eye and inferotemporally in 2 eyes. There was no displacement in 2 eyes. Zonules were enhanced in all MFS eyes compared to normals, particularly in the quadrant opposite to the direction of lens displacement or herniation.
Conclusions :
MFS patients on average showed decreased central AC depth. The lens tended to be greater in thickness than in age-matched controls and its anterior radius was significantly reduced. Ectopia lentis is a diagnostic criterion of MFS and many patients will undergo lens extraction, which may be complicated by weakened zonular support. UBM can be a useful adjunct in evaluating zonular stability and lens size and subluxation.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.