Advances in the Surgical Correction of Presbyopia

George O. Waring IV, MD; Duncan E. Berry, BA

Disclosures

Int Ophthalmol Clin. 2013;53(1):129-152. 

In This Article

Intrastromal Femtosecond Ring Incisions

Theory and Technique

Although the primary application of the femtosecond laser has been its use in the creation of the LASIK flap, its precision and safety make it a useful tool in many types of corneal refractive surgery, including the intrastromal correction of presbyopia (INTRACOR; Technolas Perfect Vision GmbH, Munich, Germany). This procedure was first described in 2009 by Ruiz and colleagues and creates a hyperprolate, multifocal cornea by making a series of intrastromal corneal ring incisions.[55,56] There are now more than a handful of femtosecond lasers in the market and they may differ from one another in their pulse energy and frequency, laser docking and applanation (flat or curved), flap creation laser delivery (raster or spiral pattern, versatility, and mobility).[57] The accepted pattern for presbyopia correction consists of 5 concentric rings that are cut in area between 2.0 and 4.0 mm from the line of sight, which is marked before surgery using the first Purkinje image.[58]

Efficacy

In the longest follow-up to date, Holzer et al[59] recently reported that at 18 months, the median uncorrected near visual acuity (UNVA) improved significantly from 0.7 logMAR preoperatively to 0.2 logMAR (P<0.001) and that the median corneal true net power increased significantly by 1.1 to 0.9 D (P<0.001). Ruiz et al[55] reported that at 6 months postoperatively, all 83 (100%) eyes had improved UNVA, with minimal or no change in UDVA. At 12 months, 22 eyes had UNVA improved to J1 with improvement in mean UDVA as well. Two (2.4%) eyes lost 2 lines of CDVA at 6 months, but this did not occur in the 22 eyes seen at 1 year. It is also important to note that Holzer et al[59] reported no gain in UNVA 1 month postoperatively. This should be kept in mind during preoperative counseling.

Safety

Corneal manipulation can be associated with a risk for keratectasia. Several cases of corneal ectasia have been reported after LASIK and photorefractive kerectomy and at least 1 case of anterior corneal protrusion after hyperopic LASIK followed by INTRACOR has been reported.[60,61] However, Holzer et al[59] reported stable corneal steepening and found no significant changes in median pachymetry at the thinnest point over 12 months postoperatively.

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