Changes in Vitreoretinal Adhesion With Age and Region in Human and Sheep Eyes.

Christopher J Creveling,Brittany Coats,Jourdan Colter

doi:10.3389/fbioe.2018.00153

Christopher J Creveling, Brittany Coats + Show 1 more

Open Access

https://doi.org/10.3389/fbioe.2018.00153

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Abstract

While several studies have qualitatively investigated age- and region-dependent adhesion between the vitreous and retina, no studies have directly measured the vitreoretinal strength of adhesion. In this study, we developed a rotational peel device and associated methodology to measure the maximum and steady-state peel forces between the vitreous and the retina. Vitreoretinal adhesion in the equator and posterior pole were measured in human eyes from donors ranging 30 to 79 years of age, and in sheep eyes from premature, neonatal, young lamb, and young adult sheep. In human eyes, maximum peel force in the equator (7.24 ± 4.13 mN) was greater than in the posterior pole (4.08 ± 2.03 mN). This trend was especially evident for younger eyes from donors 30 to 39 years of age. After 60 years of age, there was a significant decrease in the maximum equatorial (4.69 ± 2.52 mN, p = 0.016) and posterior pole adhesion (2.95 ± 1.25 mN, p = 0.037). In immature sheep eyes, maximum adhesion was 7.60 ± 3.06 mN, and did not significantly differ between the equator and posterior pole until young adulthood. At this age, the maximum adhesion in the equator nearly doubled (16.67 ± 7.45 mN) that of the posterior pole, similar to the young adult human eyes. Light microscopy images suggest more disruption of the inner limiting membrane (ILM) in immature sheep eyes compared to adult sheep eyes. Interestingly, in human eyes, ILM disruption was significantly greater in the posterior pole (p < 0.05) and in people over 60 years of age (p < 0.02). These findings supplement the current discussion surrounding age-related posterior vitreous detachment, and the risk factors and physiological progressions associated with this condition. In addition, these data further our understanding of the biomechanical mechanisms of vitreoretinal adhesion, and can be used to develop age- appropriate computational models simulating retinal detachment, hemorrhaging, or retinal trauma.

Highlights

Any disruption to the layers of the retina, the separation of the photosensitive cells from the retinal pigment epithelium, can result in blindness or severe visual impairment
By the time the sheep developed into young adults (∼28–36 years human age equivalent), the equatorial vitreoretinal adhesion significantly increased while adhesion in the posterior pole remained unchanged from the immature sheep eyes
We developed a novel device to quantify vitreoretinal adhesion in the equator and posterior pole of human and sheep eyes

Summary

Introduction

Any disruption to the layers of the retina, the separation of the photosensitive cells from the retinal pigment epithelium, can result in blindness or severe visual impairment. Sebag (1991) manually peeled the posterior vitreous from the retina in 59 post-mortem eyes from donors with ages spanning 33 weeks gestation to 100 years old. They reported that peeling was “more difficult” in younger ages (20 years old or younger). It correlates with theories that suggest vitreoretinal adhesion is a function of collagen density and structural integrity (Sebag, 1992; Fivgas and Capone, 2001; Gandorfer et al, 2001, 2002; Bishop et al, 2004; Ponsioen et al, 2008; Mitry et al, 2010). If adhesion is dependent on collagen density and structure, the decrease and weakening of collagen with age would alter and diminish adhesion at the vitreoretinal interface

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