Purchase this article with an account.
Susan A. Strenk, Bosco Tjan, Liliana Werner, Nick Mamalis, Lawrence M. Strenk; In Vivo and In Vitro MRI of Pseudophakic Human Eyes. Invest. Ophthalmol. Vis. Sci. 2011;52(14):4728.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Complications of new intraocular lens (IOL) designs are often not discovered until years after their introduction and often linked to Soemmering’s ring (SR), a growth that develops to some extent after most cataract surgeries. SR abundance is directly related to the post operative period and inversely to patient age and care taken in cortical clean-up. IOL design also plays a significant role. MRI is not impeded by the iris or optical distortions and has the unique ability to visualize the entire IOL and surrounding SR.
Donor eyes (N=100, ages 60-99) were imaged either at 1.5T (General Electric) or 3T (Siemens) using custom rf coils (MRI Research) and T1 weighting. Several donor eyes underwent gross and pathological evaluation in order to characterize SR and validate that the image contrast at 3T was comparable to 1.5T. Cataract patients (N=14, ages 69-87) were imaged at 3T to allow shorter scans, which is an important consideration for geriatric volunteers. The location, size, and nature of SR were measured with MRI, gross and histopathological analysis.
MRI revealed up to three distinct layers of SR: a dark inner-area; a concentric gray layer; and a concentric bright, outer-most layer. Gross analysis confirmed the presence of SR and pathological analysis revealed the dark areas to be calcification; the gray areas to be dense, irregular cortical material; and the bright concentric outmost layer to be normal cortical material. SR appears to reach its maximum size within several years post surgery; after which time it may become bi-lamellar, and, ultimately, tri-lamellar as the innermost layer calcifies. In-vivo images were at a lower in plane resolution (156 vs 39 microns) but were otherwise consistent with in-vitro findings.
This study cross-validates MRI of cataract patients with MRI of donor eyes, on which gross and histopathological analysis have been conducted. Accommodating-IOLs may be implanted in younger people with whom SR is likely to develop more abundantly and thus potentially lead to more complications. Additionally, A-IOLs are likely to be in place for longer periods of time, thus allowing multi-lamellar SR to develop; the resulting calcifications may limit haptic movement. Longitudinal in vivo MRI studies of cataract patients provide an opportunity to obtain timely feedback on SR development in newly introduced IOLs.
This PDF is available to Subscribers Only