Replacing monovision

Heading a LASIK centre in the Netherlands, I am often confronted with young presbyopes (with or without concomitant refractive errors) who want to get rid of their reading glasses. Up until a year ago, the most common approach that we took at our clinic was to offer these patients monovision LASIK. However, this option is plagued by several side-effects and not all patients can become accustomed to it. The availability of newer presbyopia solutions such as corneal inlays has changed the landscape of presbyopia treatment and is now allowing us to offer our patients a better quality of vision.

The Raindrop Near Vision Inlay

At our clinic, we have begun offering our presbyopic patients the Raindrop Near Vision Inlay (ReVision Optics, Lake Forest, California, USA). This is a 2 mm wide and 30 μm thick inlay that is placed in the cornea under a flap created with a femtosecond laser. The inlay shares the refractive index of the cornea and is hence virtually invisible once implanted in the eye.

With monovision, patient selection is critical, and even when performed properly, some patients will complain about lack of stereopsis, poor distance vision and unbalanced vision. The Raindrop inlay is an additive procedure, which means it doesn't remove corneal tissue, just adds the small biocompatible hydrogel; it can easily be repositioned after implantation if needed, or removed if the patient is not completely satisfied with their vision. This is another big difference against monovision, a procedure that requires an ablation, and if the patient is unhappy a second procedure (ablating even more corneal tissue) for its reversal.

Patient selection is key

I have implanted the Raindrop inlay concurrently with LASIK for refractive correction in 20 patients, and each one has been satisfied. However, the key to patient satisfaction is patient selection. When we began offering the Raindrop procedure, we offered it first to hyperopic patients who are most likely to be satisfied with the substantial gain in near vision offered by the inlay. Gradually, we began offering it to myopic patients as well.

Although patients with only slight myopia may be harder to satisfy, patients with high myopia are also excellent candidates for this procedure. In all cases however, it is important to counsel the patient on the expected outcomes of surgery before proceeding with it.

The approach that we use with hyperopic patients and that is recommended by ReVision Optics is to first do a contact lens trial in the patients. We determine the patients' refractive error and prescribe contact lenses (CL) to correct this error. Whereas the dominant eye receives a monofocal CL that only corrects the refractive error, the non-dominant, which will receive the Raindrop inlay, receives a near-centre multifocal CL that corrects the refractive error and has a near add that simulates the type of vision patients can expect to have with the Raindrop inlay. Patients who are happy with their CL vision will be most likely to be satisfied with the Raindrop inlay.