The intraocular lens inserter market has expanded rapidly over the past decade. Towards the end of 2019, over 20 different current-generation inserter devices from more than ten manufacturers were vying for attention at the ESCRS ophthalmology conference in Paris. The many legacy devices still available in certain markets add yet further to the wide variety of options available to clinicians. 

Drug delivery to the eye: overcoming the challenges of intravitreal prefilled syringes 

These recent years of progress have been marked by a series of incremental enhancements in device design – but I believe we are now on the cusp of radical improvements and significant commercial opportunity. Look at it this way: the optical quality of the intraocular lens (IOL) – the tiny artificial lens that replaces a natural lens removed during surgery – is reaching its apex, leaving little room for competitive differentiation. It is the IOL delivery device that represents the next frontier for innovation and crucial differentiation.

This article is the second in our ‘delivery to the eye’ series and follows my colleague Suresh Gupta’s insight into the challenges of intravitreal prefilled syringes. This time, I’m going to track the development arc of lens delivery, identify some of the key hurdles still to be overcome, and set out my vision for how innovation can improve both performance and patient satisfaction.

So where do we stand right now? The most notable trend we’re experiencing is the shift away from reusable, manually loaded inserters, towards single-use, preloaded devices. The newly marketed devices increasingly use this paradigm – especially in the premium tier – and in some cases include unique design elements which slightly differentiate their user interfaces and delivery performance. However, the products in this class are primarily differentiated by the quality of the technology used in their associated lenses. This remains the predominant factor for clinicians when choosing a system.

Automated lens advancement

A new class of devices is now emerging, offering all the benefits of modern single-use, preloaded systems but with enhanced features, such as single-handed use and ‘automated’ lens advancement. In principle, these features present evolution over the previous generation, but in practice have not yet achieved widespread adoption nor disrupted the market as expected. 

Arguably, this is an unsurprising outcome which merely follows a conventional diffusion of innovation trend. New innovations command a premium, initially borne by enthusiasts and visionaries, and wider adoption is achieved later once the technology is refined, more commonplace and the price has been reduced by market competition. But this competition only materialises when the breakthrough product has sufficient user appeal and tangible benefit. It remains to be seen whether these devices have addressed the right user needs. 

Before the advent of IOL injectors, surgeons manually folded lenses and pushed them through large primary incisions with forceps. Over time, this technique was superseded by manually loaded cartridge inserters, which drastically reduced the likelihood of lens damage and resulted in smaller wound sizes.  The preloaded inserters that followed simplified workflow, mitigated infection risks and eliminated reprocessing costs and logistical issues. 

These iterative developments all commanded higher price tags over their previous offering but were adopted relatively since they were combined with the latest lens technologies (for which patients were willing to accept a premium) and had clear, tangible user benefits. But as I said at the outset, the current generation of lenses is reaching a peak in terms of quality and performance, with little differentiation between similar products across providers. In many respects, users feel content with the current offerings – so future systems will need to advance more than visual performance alone in order to gain market share.

Common useability issues

So, let’s look more closely at the opportunity for innovation and differentiation. A range of common usability issues exist with the current generation of devices, and regularly cause performance related problems. Improvements can reduce complications, streamline delivery workflow and improve postoperative patient satisfaction.

The foremost need in IOL devices is to improve folding/unfolding reliability and minimise any transient damage during lens delivery. The following factors significantly affect IOL folding reliability and are key areas for innovation:

1. OVD (ophthalmic viscosurgical device) infusion. Failure to infuse sufficient OVD prior to priming, causing stiction, lens scuffing or mechanism jamming. This can disproportionately impact the effectiveness of other system elements intended to improve reliability. Enhancements might include clearer identification of fill port and fill-to markings, or elimination of the use of step through pre-lubrication of the lens within the packaging.

2. Priming. Lens folding issues caused by inconsistencies in the priming technique or sub-optimal folding geometry and tolerances. There remains potential to refine the priming process and remove some variability associated with the human element of the process.

3. Ejection control. Preventing highspeed ejection which can cause damage to internal structures. Problems here are often linked with OVD infusion and priming but can also be caused by design and manufacturing issues. Solutions should enable more consistent and predictable lens unfolding.

Let’s be clear. Building solutions to these issues into a package with a palatable cost presents significant technical challenges, which will require new and inventive solutions. Some issues may require additional components or technologies to solve, others might be overcome with a renewed focus on user-centred design. In all cases, the benefits must inspire confidence and be priced competitively to capture the market. It will be fascinating to see how manufacturers approach these challenges. Meanwhile, do drop me a line with your thoughts on other factors that might open up opportunities and new market share in this area. It would be great to continue the conversation.

Tim Phillips
Tim Phillips
Senior Human Factors Engineer

Tim is a Senior Human Factors Engineer, with a background in Design Engineering. He has a particular interest in the evaluation and integration of emergent technologies into medical devices.