This Small Business Innovation Research Phase I project aims to develop a novel intraocular lens implant (IOL) with the goal to restore full visual function in patients undergoing cataract surgery. Currently, during cataract surgery, an IOL is implanted in the capsular bag that used to contain the cataract. This lens provides focused vision at only one distance. All attempts to develop an effective variable focus (accommodating) IOL have failed, and this project concept overcomes the current limitations with a zonular capture haptic (ZCH) that has individual components. The company has established proof of concept in animal models and shown that a ZCH parallels the movement of the ciliary body that controls focus within the eye. The technical goals of this project are to measure the actual forces exerted by the eye during accommodation using a ZCH dynamometer, and then use these measurements to engineer and perfect our ZCH prototypes.
The broader impact/commercial potential of this project is addressing the degradation of sight affecting almost every person. By 2020 it is estimated that 30 million Americans will suffer from cataracts and 9.5 million people would have undergone cataract surgery. All human beings are affected by presbyopia (inability to focus up close) if their life span extends past the fourth decade of life. ?Premium? IOLs such as Bausch and Lomb?s Crystalens, Abbott Medical Optics? ReZoom, and Alcon?s ReSTOR only achieve one diopter of accommodation equivalent which is inadequate. Yet about 7% of cataract patients pay about $2,000 out of pocket per eye above their Medicare coverage to receive a Premium IOL. The worldwide market size for Premium IOLs is approximately $500MM. In addition 700,000 patients undergo refractive surgery via Lasik-type procedures each year and pay $2,000-$6,000 per eye with the possibility of later requiring cataract surgery and the certainty of needing reading glasses. If successful, the proposed ZCH would be the sole technology that restores movement to an IOL and as such has the potential of being a successful surgery that corrects cataracts, refractive errors and presbyopia.
This Small Business Innovation Research Phase I project had an eventual objective of developing a novel intraocular lens implant (IOL) with the goal to restore full visual function in patients undergoing cataract surgery. Currently, during cataract surgery, an IOL is implanted in the capsular bag that used to contain the cataract. This lens provides focused vision at only one distance. All attempts to develop an effective variable focus (accommodating) IOL have failed. Our novel concept is to replace the function of the capsule bag with a zonular capture haptic (ZCH) that has individual components, and then section the capsule bag to free the ZCH movement thus creating an accommodative- disaccommodative intraocular lens system (AD-IOL). We have established proof of concept in animal models and have shown that a ZCH parallels the movement of the ciliary body in the eye. Our innovation solves the rigidity problem associated with the capsular bag contraction and fibrosis following cataract surgery. Capsular bag rigidity is a common denominator that limits the effectiveness of current accommodative IOL’s. For an IOL to correct presbyopia, that IOL must harness the forces of accommodation. Therefore, obtaining an accurate measurement of the force of accommodation, i.e. the force the zonules exert on the capsular bag, is a critical element in the design criteria of an A-IOL. All research efforts to measure these forces in the past have been conducted in vitro, in cadaver eyes with complex external apparatus that potentially introduce extraneous error in the force calculation. The goal of this Phase I was to measure the actual forces exerted by the eye during accommodation using a ZCH dynamometer, and then use these measurements to engineer and perfect our existing AD-IOL prototypes. Before the start of our Phase I project, we performed experiments using our own funds that showed that an experimental ZCH-based A-IOL could generate substantial axial movement and achieve an average of four diopters of accommodation – in comparison, current A-IOL designs have not surpassed two diopters of accommodation. We subsequently designed a dynamometer based on the knowledge gained in our earlier experiments, which also allowed us to advance our product design. Two of these newly designed dynamometers were implanted into a rhesus monkey and we were able to successfully measure in vivo accommodative forces of the eye. Our results show a force of <40mN for maximal disaccommodation of our thinnest Nitinol device, although the evidence suggests a thinner, more responsive device would have been more optimal. Furthermore, the experience we gained working with Nitinol and the data we were able to gather put us in an enviable position as we continue on our design and development path. Using the data generated, we have already manufactured new ZCH devices and begun experimenting with them.
