SEM study suggests earlier onset of cataract in diabetes

CHAPEL HILL, N.C. — A study using scanning electron microscopy seems to confirm the idea that cataract may have an earlier onset in people with diabetes than those without the disease. Researchers here said their study suggests diabetes may lead to a higher nuclear lens compaction rate.

M. Joseph Costello and colleagues at the University of North Carolina at Chapel Hill and at Ruth-Presbyterian-St. Luke’s Medical Center in Chicago obtained six diabetic human lenses without cataract at 4 to 6 hours postmortem. They compared these to six human nuclear cataractous lens nuclei removed from patients with diabetes using extracapsular extraction. The researchers measured anterior and posterior fetal nuclear elliptical angles and embryonic nuclear anterior-posterior axial thickness.

Statistical analysis indicated significant differences in the measurements between transparent and nuclear cataractous diabetic lenses in all examined parameters, the researchers reported in BMC Ophthalmology.

Diabetic lenses with nuclear cataract exhibited smaller elliptical angle, smaller axial thicknesses and more compaction folds than noncataractous diabetic lenses.

“It appears that nuclear fiber cell compaction is responsible for these differences,” the authors said. Nuclear fiber cell compaction in the lens is normal and measurable, they said. Diabetes may elicit an increased compaction rate as well as an earlier onset of cataract formation.