Scleral expansion: A legitimate contender in the presbyobia arena?

Implications: This article describes the Phase II trial results of the PreView Scleral Implants (ReFocus Group Inc.) for the treatment of presbyopia.  Presbyopia is the natural age related loss of accommodation, or near focusing ability that leads to people wearing reading glasses. Scleral implants alter the configuration of the eye around the lens equator allowing some restoration of accommodation.  The Phase I trials with scleral implants were of limited success.  The Phase II Trials utilized an automated tunneling device designed to ease the surgical procedure.  As well, changes were made to the scleral implants enhancing stability.  The six month postoperative data shows that 80% of patients had 20/40 vision at near without significant loss of distance vision.  Phase III trials began enrolling in summer of 2006 and have currently enrolled more than 150 eyes. 

Analysis: While the visual results of scleral implants appear to be promising, there are still significant questions about the safety and the difficulty of this procedure.  When evaluating treatments for presbyopia, several important issues exist including quality of near vision, preservation of distance vision, reversibility of the procedure, technical difficulty of the procedure, and overall safety of the procedure.  When compared to the other available options for presbyopia, scleral implants are significantly more invasive and have a higher potential for complications.  This is due to the fact that the implants have to be placed in the sclera which can lead to inflammation and erosion. Given the other less invasive presbyopia options available such as multifocal lenses, intracorneal lenses, conductive keratoplasty, and multifocal LASIK, it is unlikely that a more invasive procedure is likely to catch on.