This article is more than 5 years old. Information may no longer be current.
Prismatic IOL restores vision in patients with macular degeneration
The implant redirects light towards a peripheral, healthy area of the retina.
Click Here to Manage Email Alerts
Patients with AMD and other vision-impairing macular diseases can benefit from the use of a prismatic IOL system, which redirects light away from diseased tissue and toward a peripheral portion of healthy retina, according to one surgeon.
“Of all the currently available treatment options, this is the one that has the best results in terms of visual recovery. All the patients I have implanted are extremely satisfied,” said Emilio Balestrazzi, MD. Compared to other telescopic implants, he added, this system has the advantage of allowing bilateral implantation if both eyes are affected.
A rehabilitation program
According to Dr. Balestrazzi, the LenSpecial IOL-Vip system is a complete low-vision rehabilitation package, encompassing a preoperative simulator, two lenses and special software programmed with customized visual rehabilitation exercises. In addition to the surgical implantation, the system requires the presence of a low-vision rehabilitation center with qualified personnel to perform the delicate pre- and postoperative stages, he said. The rehabilitation program begins 15 days before surgery and concludes at least 3 months after implantation.
“This treatment program can be offered to patients with stabilized macular degeneration, with or without crystalline lens opacification. The axial length should be within 20.5 mm and 29.5 mm. Patients must, of course, have a healthy cornea and a sufficiently large area of healthy retina around the macula,” Dr. Balestrazzi said.
Before surgery, the IOL-Vip system software is used to localize and stimulate the area of healthy retina to which the light rays will be redirected, and to determine the orientation of the prismatic IOL, he explained. With the aid of a telescope, the patient is then guided through a series of exercises that simulate the postoperative visual outcome in terms of distance and near vision.
“After 2 weeks, if the preoperative training has been successful, the patient is ready for implantation,” he said.
Surgery only requires small variations from the classic phacoemulsification procedure, he said. A slightly larger capsulorrhexis is performed, and the incision is enlarged to 7 mm for inserting the two IOLs, which are slightly thicker than standard IOLs.
“Of the two lenses, one is a biconcave negative lens of –64 D, which is implanted in the capsular bag. The other one is a biconvex positive lens of +53D, which is fixated to the angle in the anterior chamber,” Dr. Balestrazzi said.
“The two lenses together have the effect of both magnifying (1.3X) and re- directing, with a prismatic effect, the image to a peripheral area, more often temporal in respect to the macula. This new ‘preferred retinal locus’ (PRL) becomes the patient’s new macula,” he said.
Encouraging results
In the 3 months after surgery, the patient follows an intensive program of visual training to adapt the eye and the brain to the new eccentric fixation. Part of the training is guided by low-vision experts, but some of the exercises included in the software can be performed by the patient at home, Dr. Balestrazzi said.
“We have been using the IOL-Vip system in four centers in Italy, and a total of 150 implants have been performed so far,” he noted.
“We are in the process of publishing our data, and the outcomes appear to be extremely encouraging. No complications besides the usual adverse events of cataract surgery have been reported. All patients have regained lines of useful vision and are happy with their results, particularly concerning near vision. All of them were highly motivated to follow the complete rehabilitation program,” he said.
He added that this is the first treatment option for macular diseases that can realistically promise an improvement of vision. It is also versatile and can be an option for a number of macular conditions, such as atrophic or wet macular degeneration, myopic maculopathy, Stargardt disease and macular holes, he said.
For Your Information:
- Emilio Balestrazzi, MD, can be reached at Universita Cattolica Del Sacro Cuore, 00168 Roma (RM) 8, lg. Gemelli; 39-06-30151; fax: 39-06-3051343; emibale@tin.it. Dr. Balestrazzi has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
- LenSpecial S.R.L., makers of the IOL-Vip system, can be reached at Corso Buenos Aires, 52, 20124, Milano, Italy; 39-3356562576; fax: 39-02700524571; Web site: www.lenspecial.com.
- Michela Cimberle is an OSN correspondent based in Treviso, Italy.