PURPOSE: To explore the attachments of the posterior zonule and vitreous in relation to accommodation and presbyopia in monkeys and humans. METHODS: Novel scanning electron microscopy (SEM) and ultrasound biomicroscopy (UBM) techniques were used to visualize the anterior, intermediate, and posterior vitreous zonule and their connections to the ciliary body, vitreous membrane, lens capsule, and ora serrata, and to characterize their age-related changes and correlate them with loss of accommodative forward movement of the ciliary body. alpha-Chymotrypsin was used focally to lyse the vitreous zonule and determine the effect on movement of the accommodative apparatus in monkeys. RESULTS: The vitreous attached to the peripheral lens capsule and the ora serrata directly. The pars plana zonule and the posterior tines of the anterior zonule were separated from the vitreous membrane except for strategically placed attachments, collectively termed the vitreous zonule, that may modulate and smooth the forward and backward movements of the entire system. Age-dependent changes in these relationships correlated significantly with loss of accommodative amplitude. Lysis of the intermediate vitreous zonule partially restored accommodative movement. CONCLUSIONS: The vitreous zonule system may help to smoothly translate to the lens the driving forces of accommodation and disaccommodation generated by the ciliary muscle, while maintaining visual focus and protecting the lens capsule and ora serrata from acute tractional forces. Stiffening of the vitreous zonular system may contribute to age-related loss of accommodation and offer a therapeutic target for presbyopia.
PURPOSE: To explore the attachments of the posterior zonule and vitreous in relation to accommodation and presbyopia in monkeys and humans. METHODS: Novel scanning electron microscopy (SEM) and ultrasound biomicroscopy (UBM) techniques were used to visualize the anterior, intermediate, and posterior vitreous zonule and their connections to the ciliary body, vitreous membrane, lens capsule, and ora serrata, and to characterize their age-related changes and correlate them with loss of accommodative forward movement of the ciliary body. alpha-Chymotrypsin was used focally to lyse the vitreous zonule and determine the effect on movement of the accommodative apparatus in monkeys. RESULTS: The vitreous attached to the peripheral lens capsule and the ora serrata directly. The pars plana zonule and the posterior tines of the anterior zonule were separated from the vitreous membrane except for strategically placed attachments, collectively termed the vitreous zonule, that may modulate and smooth the forward and backward movements of the entire system. Age-dependent changes in these relationships correlated significantly with loss of accommodative amplitude. Lysis of the intermediate vitreous zonule partially restored accommodative movement. CONCLUSIONS: The vitreous zonule system may help to smoothly translate to the lens the driving forces of accommodation and disaccommodation generated by the ciliary muscle, while maintaining visual focus and protecting the lens capsule and ora serrata from acute tractional forces. Stiffening of the vitreous zonular system may contribute to age-related loss of accommodation and offer a therapeutic target for presbyopia.
Authors: Mary Ann Croft; Jared P McDonald; Alexander Katz; Ting-Li Lin; Elke Lütjen-Drecoll; Paul L Kaufman Journal: Invest Ophthalmol Vis Sci Date: 2013-07-26 Impact factor: 4.799
Authors: Mary Ann Croft; T Michael Nork; Jared P McDonald; Alexander Katz; Elke Lütjen-Drecoll; Paul L Kaufman Journal: Invest Ophthalmol Vis Sci Date: 2013-07-26 Impact factor: 4.799
Authors: Yanrong Shi; Yidong Tu; Alicia De Maria; Robert P Mecham; Steven Bassnett Journal: Invest Ophthalmol Vis Sci Date: 2013-04-01 Impact factor: 4.799
Authors: Mary Ann Croft; Gregg Heatley; Jared P McDonald; Alexander Katz; Paul L Kaufman Journal: Ophthalmic Physiol Opt Date: 2016-01 Impact factor: 3.117
Authors: Cassandra M Flügel-Koch; Mary Ann Croft; Paul L Kaufman; Elke Lütjen-Drecoll Journal: Ophthalmic Physiol Opt Date: 2015-10-21 Impact factor: 3.117
Authors: Adam M Zysk; Alfred B Garson; Qiaofeng Xu; Eric M Brey; Wei Zhou; Jovan G Brankov; Miles N Wernick; Jerome R Kuszak; Mark A Anastasio Journal: Biomed Opt Express Date: 2012-07-24 Impact factor: 3.732