Preva­lence of myopia (short­sight­ed­ness) increases consid­er­ably in indus­tri­al­ized countries. The mecha­nisms behind this devel­op­ment need to be fully under­stood in order to attain preven­tion. Research has previ­ously provided indica­tions support­ing a possi­ble link between myopia onset and near vision. The process of chang­ing the eye lens’ refrac­tive power to adapt to differ­ent viewing distances, referred to as accom­mo­da­tion, is initi­ated by the ciliary muscle.

This PhD project, super­vised by Hector Fellow Eberhart Zrenner, compared the accom­mo­da­tion system of young adults with myopia and emmetropia (normal sight­ed­ness) regard­ing changes in both crystalline lens power and ciliary muscle morphol­ogy during regular and sustained accom­mo­da­tion. Further­more, the possi­bil­ity to volun­tar­ily control accom­mo­da­tion using auditory biofeed­back train­ing was assessed.

Inves­ti­ga­tions of the ciliary muscle’s anatomy were realized using the imaging technique of optical coher­ence tomog­ra­phy (see Figure), and a new approach to evalu­ate morpho­logic changes during the muscle’s contrac­tion was devel­oped. This tool will lay the scien­tific founda­tion for under­stand­ing how the ciliary muscle’s anatom­i­cal changes may corre­late with the neuronal signals control­ling its activity.

Findings derived from this project will allow a better under­stand­ing of accom­mo­da­tion, address unanswered question regard­ing myopia onset, and support the devel­op­ment of new devices.