Ophthalmology

Refractive interventions are widespread techniques for vision correction such as myopia or astigmatism. The cornea of the patient is reshaped by surgical intervention like incisions and laser ablation of stromal tissue. The amount of tissue to remove is traditionally estimated based on experimental nomograms or geometrical approaches. Unfortunately, the change of corneal power is frequently over- or under-estimated.

We proposed an opto-mechanical simulation framework to quantify the optical outcome induced by alteration of the corneal biomechanics. This numerical framework was used to perform personalized simulations of different surgical procedures such as corneal ring implantation and arcuate keratotomy. For example, arcuate keratotomy is a surgical technique used to correct astigmatism following cataract interventions. Our numerical simulation framework could estimate the outcome of different planning options before the surgery. Based on this numerical approach, we were also able to propose optimization algorithms to automatically determine the surgical parameters optimal for each specific patient. The patient-specific optimization of the surgery proved to better control the outcome of the intervention, leads to more reliable postoperative astigmatism, and limits the risks of overcorrection.

Hydrogel microinjections for vision correction

By 2050, more than five billion people are expected to be affected by refractive vision disorders such as presbyopia, myopia and astigmatism. Current surgical options rely largely on laser procedures that reshape the cornea by removing tissue. Although effective in many cases, these techniques reduce corneal strength and carry a risk of complications. They are also unsuitable for patients with thin corneas or high refractive errors. To respond to these limitations, we are developing a novel treatment based on hydrogel injections into the cornea to correct hyperopia while preserving corneal integrity. This approach represents a promising alternative for individuals who are not eligible for conventional laser surgery, including patients with conditions such as keratoconus.

Our technique improves vision through highly controlled microinjections of hydrogel that form implants inside the corneal stroma. These implants remodel the cornea and reinforce its structure at the same time.

We demonstrated in an in vivo animal study the feasibility of the procedure. The treatment successfully corrected large refractive errors, showed good long-term stability of the hydrogel, and revealed no signs of adverse reaction or hydrogel opacification (Fig. 4). This study provides strong support for the future translation of the technology.