Magnetic resonance imaging of aging, accommodating, phakic, and pseudophakic ciliary muscle diameters

Purpose To quantify in vivo accommodative changes in the aging human ciliary muscle diameter in phakic and pseudophakic eyes. Setting Department of Surgery/Bioengineering, UMDNJ–Robert Wood Johnson Medical School, Piscataway, and the Institute of Ophthalmology and Visual Science UMDNJ–New Jersey Medical School, Newark, New Jersey, USA. Methods Images were acquired from 48 eyes of 40 people between the ages of 22 and 91 years, 1 eye of 32 phakic volunteers and both eyes of 8 patients who had monocular implantation of a single-piece AcrySof intraocular lens (IOL) (Alcon Laboratories). Images were acquired during physiological accommodation and with accommodation at rest, and the diameter of the ciliary muscle ring was measured. Results Results show the ciliary muscle remains active throughout life. The accommodative change in its diameter (mean 0.64 mm) ( P P P Conclusion Although the undiminished ability of the ciliary muscle to decrease its diameter with accommodation can be relied on in strategies for presbyopia correction, even in advanced presbyopia, the decreasing circumlental space and its potential effects on zonular tension must also be considered.