2969: effect of scleral spacers on presbyopia
This patient’s pursuit of spectacle independence via radial keratotomy, PRK for the subsequent hyperopia, and the scleral expansion bands for presbyopia presents a highly complex surgical landscape. Scleral expansion bands failed because they relied on a flawed premise of tightening zonules based on Schachar’s hypothesis of a crowded lens. This directly contradicts the accepted Helmholtz theory of accommodation where ciliary contraction relaxes zonular tension to allow the lens to round up. Additionally, scleral remodeling led to swift regression of the effect. For cataract surgery, the primary challenge is avoiding old radial incisions to prevent intraoperative dehiscence. With just 6 RK cuts we can place our incision between these prior incisions without intersecting them. Furthermore, the combination of central irregular astigmatism from PRK and structural changes from radial keratotomy creates significant higher order aberrations. Surgeons must completely avoid diffractive multifocal optics, instead opting for a monofocal or perhaps a small aperture lens to prevent devastating degradation of contrast sensitivity. We have been pursuing an effective treatment for presbyopia for so many decades, but still….
