Corneal characteristics in children with Marfan syndrome with or without ectopia lentis.

Importance: Myopia of Marfan syndrome (MFS) may be ascribed to crystalline lens subluxation, abnormal corneal curvature, and increased globe axial length. Few studies have reported these measures in MFS children who did or did not have ectopia lentis (EL).

Objective: To measure eye findings longitudinally in MFS children with and without EL.

Methods: A prospective, comparative case study was conducted on 24 MFS children (48 eyes). EL necessitated lensectomy and intraocular lens implantation surgery in 16/24 children (mean age 5.6 ± 2.8 years). The remaining 8/24 MFS children (mean age 11.2 ± 4.2 years) had no EL and were phakic. Follow-up was a mean of 3.1 ± 0.5 years. At follow-up visits, visual acuity, tonometry, refractive error, central corneal thickness (CCT), biomicroscopic examination, axial length, anterior chamber depth, endothelial cell density (ECD), and corneal curvature were monitored.

Results: At the initial visit, before EL surgery, MFS children with EL had greater myopia (P < 0.01), corneal cylinder (P = 0.04), and CCT (P = 0.01) compared to children with no EL. Over the follow-up interval, EL children had a progressive increase in CCT (P = 0.02) and a reduction in ECD (P = 0.02). EL children also showed: progressive flattening of corneal curvature (P = 0.01); reduction of corneal cylinder (P = 0.02); and increase in axial length (P < 0.01). MFS children with no EL exhibited a smaller increase in CCT (P < 0.01) and a milder flattening of corneal curvature (P < 0.01). The no EL children showed no change in ECD (P = 0.09), corneal cylinder (P = 0.80), or axial length (P = 0.27).

Interpretation: MFS children who have EL exhibit differences in corneal structure and axial length when compared to MFS children with no EL. Children with EL have thicker CCT, more corneal cylinder, lower ECD, and longer axial lengths compared to children with no EL. The differences imply that the fibrillin defect of MFS is more severe in children with EL. The ocular defect is manifested chiefly as zonular hyperextension but has effects also on corneal and scleral integrity.