title: The accommodative ciliary muscle function is preserved in older humans.
abstract: Presbyopia, the loss of the eye's accommodation capability, affects all humans aged above 45-50 years old. The two main reasons for this to happen are a hardening of the crystalline lens and a reduction of the ciliary muscle functionality with age. While there seems to be at least some partial accommodating functionality of the ciliary muscle at early presbyopic ages, it is not yet clear whether the muscle is still active at more advanced ages. Previous techniques used to visualize the accommodation mechanism of the ciliary muscle are complicated to apply in the older subjects, as they typically require fixation stability during long measurement times and/or to have an ultrasound probe directly in contact with the eye. Instead, we used our own developed method based on high-speed recording of lens wobbling to study the ciliary muscle activity in a small group of pseudophakic subjects (around 80 years old). There was a significant activity of the muscle, clearly able to contract under binocular stimulation of accommodation. This supports a purely lenticular-based theory of presbyopia and it might stimulate the search for new solutions to presbyopia by making use of the remaining contraction force still presented in the aging eye.
authors.affiliation: Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Tabernero
authors.affiliation: Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chirre
authors.affiliation: Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Hervella
authors.affiliation: Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Prieto
authors.affiliation: Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Artal
mesh_terms: D000065:Accommodation, Ocular; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D019591:Pseudophakia