Morphometric Assessment of the Ciliary Body in Patients With Marfan Syndrome and Ectopia Lentis: A Quantitative Study Using Ultrasound Biomicroscopy

To explore the biometric characteristics of the ciliary body in patients with Marfan syndrome (MFS) and ectopia lentis (EL).Cross-sectional study.Seventy-two consecutive patients with MFS and EL and 72 nondiseased control subjects were recruited. Ciliary body biometric parameters such as ciliary muscle cross-sectional area at 2000 µm from the scleral spur (CMA2000), ciliary muscle thickness at 1000 µm from the scleral spur (CMT1000), and maximum ciliary body thickness (CBTmax) were measured from multiple directions with ultrasound biomicroscopy (UBM). The relationship between ciliary body parameters and other ocular characteristics was also evaluated.Average CMA2000, CMT1000, and CBTmax were 0.692 ± 0.015 mm2, 0.405 ± 0.010 mm, and 0.855 ± 0.023 mm in eyes of patients with MFS, respectively, and were significantly smaller than these values in control subjects (all P < .001). The prevalence of ciliary body thinning was 22.2% in the MFS group vs 0 in the control group (P < .001); eyes with more severe EL had smaller CMA2000 (P = .050), thinner CMT1000 (P = .022), and shorter CBTmax (P = .015). Patients with microspherophakia (MSP) had even smaller CMA2000 (P = .033) and CMT1000 (P = .044) than those without MSP. The most common subluxation direction was in the superonasal quadrant (n = 25; 39.7%), which probably correlates with the thinnest CMT1000 in the inferotemporal quadrant (P = .005).Patients with MFS and EL had thinner ciliary muscles, shorter ciliary processes, and a higher prevalence of ciliary body thinning, especially those with MSP. Both the extent and direction of subluxation were associated with ciliary body biometry..