Posters

Extralenticular influences on accommodation and the possibility of restoration of accommodation by decreasing ocular rigidity

Poster Details

First Author: A.Hipsley USA

Co Author(s):    Z. Boskai   D. Goldberg   D. Ma   M. Jackson     

Abstract Details

Purpose:

To present a model for extralenticular forces involved in accommodation, and propose a method to address these forces to allow restoration of accommodation in presbyopic eyes by decreasing ocular rigidity.

Setting:

Resources for this presentation were gathered from work done at Goldberg Eye in Little Silver, New Jersey in collaboration with a single arm IRB clinical trial at Chang Gung Memorial Hospital in Taipei, Taiwan and the Budapest University of Technology & Economics in Budapest, Hungary.

Methods:

While lenticular changes are primarily responsible for presbyopia, recent evidence in the literature have accredited some loss of accommodation to extralenticular biomechanics which undergo the same age-related changes as other tissues in the eye. Goldberg's Postulate incorporates zonular apparatus, the ciliary body, vitreous, sclera and choroid into the phenomenon of accommodation. Ultrasound biomicroscopy has identified changes in extralenticular ocular anatomy suggesting their role in accommodation. Ocular rigidity has also become a recent interest in correlation to age-related clinical significance. All ocular tissues are made of collagen and are impacted by age, showing an increase in ocular rigidity and scleralsclerosis. The amount of accommodation lost with age related to extralenticular apparatus (primarily the zonules, choroid, and sclera) is postulated based upon a computer-based model. Treatment of these changes may be performed without IOL exchange. Laser Anterior Ciliary Excision (LaserACE) procedure uses a 2.94µm Er:Yag laser in four quadrants on the sclera over the ciliary muscle in three key zones may restore function to these extralenticular structures. Empirical evidence from a LaserACE IRB clinical trial is utilized to simulate the mechanism of action extralenticular effects on the biomechanics of accommodation using the computer model.

Results:

Based upon a computer model, the LaserACE procedure is hypothesized to address the aging changes of the sclera, zonular apparatus and choroid by manipulating biomechanical properties of the sclera. Clinical trials results in 24 subjects over 40 years of age with a clear lens and otherwise healthy eyes were analyzed over 18 months and a biomechanical model of mechanism of action is presented. The greater than 1.50D of accommodation restored using this technique as well as wavefront findings showing changes in spherical aberrations and depth of focus suggest that manipulation of ocular rigidity may result in extralenticular alternations that can restore some accommodation function.

Conclusions:

The identification of the contribution of extralenticular forces to lenticular changes in accommodation, as well as the effect on aging upon these structures as related to presbyopia may define a new treatment strategy for presbyopia. Extralenticular treatments unrelated to IOL exchange may enable restoration of enough accommodative ability to allow functional improvement of reading vision at 60cm and 40cm. Utilizing model-based reasoning, it is shown that supporting an extralenticular component to accommodation and demonstrating an alternative to the 'vitreous support' theories is an evidence based model. Clinical trial results in 24 subjects over 40 years of age with a clear lens and otherwise healthy eyes followed over 18 months suggest greater than 1.50D of accommodation may be safely restored using this technique. This treatment focuses on reducing ocular rigidity by creating a matrix of ablations over the critical anatomy of the ciliary complex. Improvement in visual acuity at 60cm and 40cm was sustained over 18 mos. Stereoacuity improved significantly. This potentially gives empirical evidence that restoration of accommodation by manipulating extralenticular structures demonstrates clinical significance. FINANCIAL INTEREST: One of more of the authors... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, One of more of the authors... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented