Most patients who undergo IOL implantation, especially those who previously presented for presbyopia correction, desire spectacle independence. In many cases, however, some degree of refractive error persists postoperatively. When this error is significant enough to affect vision, a new dilemma arises: What enhancement method is best?
As a less traumatic option than IOL explantation and one that can also be performed in eyes contraindicated for laser correction, I prefer implanting a supplementary IOL to correct a refractive surprise in these instances. However, if an IOL designed for the capsular bag is used for this purpose and implanted in the sulcus, complications such as interlenticular opacification, red rock syndrome, pigment dispersion, and iris chafing can result. Newer supplementary IOLs such as the Sulcoflex (Rayner Intraocular Lenses Ltd.), which is designed specifically for sulcus implantation, eliminate these problems. In the rare case of patient dissatisfaction, the IOL can be removed without causing trauma to surrounding eye structures.
ENCOURAGING RESULTS
In a recent study, we implanted Sulcoflex IOLs in eight eyes (seven patients); five received the aspheric monofocal design, two received the multifocal design, and one received the toric design. All patients had undergone capsular bag implantation of a primary IOL at least 6 months prior to supplementary IOL implantation.
Results achieved 6 months after supplementary IOL implantation were extremely encouraging. Each patient had a BCVA of 20/25 or better and showed improvement in distance UCVA that resulted in an overall reduction in spectacle dependence. The mean spherical equivalent decreased from -1.25 D (±0.25 D; range, -2.00 D to 4.00 D) preoperatively to -0.25 D (±0.40 D; range, -0.50 to 0.25 D) postoperatively. No complications were observed.
IOL POWER CALCULATION, SURGICAL PEARLS
Rayner’s free online IOL power calculation service, Raytrace, is accessible at rayner.com/raytrace (Figure 1). If postoperative ametropia is in the range of ±7.00 D, the required lens power usually corresponds to the spherical equivalent multiplied by 1.2 in myopic eyes and by 1.5 in hyperopic eyes. In essence, the only information required may be the present refraction of the pseudophakic eye.
In my experience, an astigmatism-neutral incision of 2.6 to 3.0 mm can be used for insertion of the Sulcoflex. I inject a cohesive ophthalmic viscosurgical device into the anterior chamber and behind the iris before implantation. The IOL’s soft hydrophilic acrylic material unfolds smoothly, and its large haptics find their way to the sulcus angle almost automatically. In some cases, particularly in pediatric patients and in small eyes, a small peripheral iridotomy may be required.
REINVENTING THE SUPPLEMENTARY IOL
My experience with the Sulcoflex demonstrates that correction of pseudophakic ametropia and enhancement of postsurgical results can be achieved with sulcus implantation of a supplementary IOL. This IOL is available in aspheric, multifocal, toric, and multifocal toric designs and can be implanted during a secondary procedure in cataract patients who require further visual enhancement. Alternatively, it can be implanted at the same time as a primary IOL in a Sulcoflex duet procedure.
The reversibility of Sulcoflex implantation provides a new dimension to the role of supplementary IOLs. These lens designs have come a long way since the early days of piggyback lenses in the capsular bag. The Sulcoflex takes the guesswork out of residual error correction, offering a userfriendly solution that is safe, predictable, and reversible.
Ryan D’Souza, MD, practices at The Center for Eye Diagnostics and Surgery, Mumbai, India. Dr. D’Souza states that he has no financial interest in the products or companies mentioned. He may be reached at e-mail: drryandsouza@ gmail.com.
