Abstract
Purpose: :
To determine the differences in total, corneal and internal aberrations between eyes diagnosed with ectopia lentis associated with Marfan syndrome and normal eyes.
Methods: :
The Nidek OPD-Scan topographer and wavefront aberrometer was used to measure the ocular and corneal aberrations to the sixth Zernike order for a 5 mm zone. One hundred and forty four eyes (144 patients) diagnosed as normal and 53 eyes (29 patients with Marfan syndrome) diagnosed with ectopia lentis were compared for differences in root mean square (RMS) values of the total, corneal and internal aberrations.
Results: :
RMS coefficients were lower in eyes free of ocular pathology (normal eyes) compared to eyes with ectopia lentis with respective values of 2.88 ± 2.34 microns and 3.98 ± 3.74 microns (p=0.01). The differences between the 2 groups were mainly significant for the internal aberrations, with the mean RMS of Tilt, High Order, Total Coma, Total Trefoil, Total QuadraFoil, Total Spherical aberration, and Total Astigmatism respectively of 0.24 ± 0.13 microns, 0.27 ± 0.13 microns, 0.09 ± 0.04 microns, 0.15 ± 0.11 microns, 0.07 ± 0.06 microns, 0.13 ± 0.06 microns and 0.05 ± 0.04 microns for normal eyes, and of 0.89 ± 1.14 microns, 0.68 ± 0.63 microns, 0.39 ± 0.43 microns, 0.4 ± 0.4 microns, 0.16 ± 0.18 microns, 0.11 ± 0.14 microns and 0.13 ± 0.13 microns for eyes with ectopia lentis (p< 0.00001). There was no statistical difference in corneal aberrations between the 2 groups except for the spherical aberration which was significantly lower in eyes with ectopia lentis with a mean RMS value of 0.09 ± 0.06 microns versus 0.11 ± 0.04 microns (p=0.004).
Conclusions: :
Increased optical aberrations in patients with Marfan syndrome are mainly caused by the internal aberrations secondary to ectopia lentis. Flatter keratometry in Marfan patients (40.9 D vs 43.1 D in normal eyes) may account for the lower corneal spherical aberration in these eyes.
Keywords: optical properties • imaging/image analysis: clinical • anterior segment