[The morphology and thickness of cornea in patients with Marfan syndrome].

OBJECTIVE

To search for the characteristics of MFS in corneal morphology and thickness.

METHODS

Twenty-four patients (48 eyes) with MFS and 24 healthy age- and gender-matched volunteers (48 eyes) were recruited in this clinical prospective, and comparative series study. Firstly, biomicroscopic examination and Type-A ultrasonometry was conducted to search for ectopia lentis and axis length. Secondly, the corneal morphologic parameter [including the height of anterior and posterior surface, the centre corneal curvature, the mean astigmatism in the 3.0-mm central zone (Mean A), the mean simulated astigmatism (Sim A), the mean keratometry in the 3.0-mm central zone (Mean K), the mean simulated keratometry (Sim K), the 3.0-mm zone irregularity (3.0ZI), the 5.0-mm zone irregularity (5.0ZI), corneal thickness index (CTI)] and thickness (at the central location and at eight midperipheral locations) were obtained by the the autorefractometer and the Orbscan II Z corneal topography. Last, the statistics method including Crosstabs, One-way ANOVA, student-t test and discriminant analysis were applied and the correlations were established.

RESULTS

There is no statistically significance between MFS group and control group in ages (38 ± 7) and (37 ± 8) years, gender (8/16) and (9/15), and axis length (23.12 ± 1.06) mm and (24.26 ± 2.96) mm (age χ(2) = 0.091, P = 0.763;gender t = 0.324, axis length t = 1.976, P > 0.05). Flat cornea ratio (66.7% and 12.5%) and topography of the oval (25.0% and 16.7%), irregular bow-shaped (41.7% and 37.5%) and irregular-shaped (12.5% and 8.3%) were increased significantly in patients with MFS. The corneal topography (MFS/control) showed that there are statistically significance in the thinnest thickness of cornea (489.8 ± 42.9)µm and (544.8 ± 25.7)µm, Mean K (40.60 ± 1.30) D and (42.80 ± 1.40) D, Sim K (40.50 ± 1.30) D and (42.80 ± 1.20) D, Sim A (1.08 ± 0.86)D and (0.91 ± 0.46) D, CTI 1.57 ± 0.24 and 1.21 ± 0.14, 3.0ZI (1.76 ± 0.96) D and (1.54 ± 0.82) D, and 5.0ZI (1.91 ± 1.26) D and (0.92 ± 0.68) D (thinnest thickness t = 6.996, Mean K t = 2.554, Sim K t = 3.326, Sim A t = 2.324, CTI t = 3.116, 3.0ZI t = 2.686, 5.0ZI t = 3.768, P < 0.05), while no statistically significance in the Mean A between the MFS (1.11 ± 0.89) D and control group (0.99 ± 0.49) D (Mean A t = 1.898, P = 0.08); except for temple inferior, the significant decrease of pachymetry (including the center and the seven midperipheral locations) appeared in the MFS group compared with the control group.

CONCLUSION

The characteristic of MFS in corneal topography is that corneal axial refractive power descends and corneal thickness decreases.